Advanced Traffic Management Systems - · PDF fileto exercise engineering judgement and...

Advanced Traffic Management Systems

Ontario Traffic Manual

December 2007

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Ontario Traffic Manual • December 2007 1

Book 19 • Advanced Traffic Management Systems

OntarioTraffic Manual

Foreword

The purpose of the Ontario Traffic Manual (OTM)is to provide information and guidance fortransportation practitioners and to promoteuniformity of treatment in the design, application andoperation of traffic control devices and systemsacross Ontario. Further purposes of the OTM are toprovide a set of guidelines consistent with the intentof the Highway Traffic Act and to provide a basis forroad authorities to generate or update their ownguidelines and standards.

The OTM is made up of a number of Books, whichare being generated over a period of time, and forwhich a process of continuous updating is planned.Through the updating process, it is proposed that theOTM will become more comprehensive andrepresentative by including many traffic controldevices and applications specific to municipal use.Some of the Books of the OTM are new, while othersincorporate updated material from the OntarioManual of Uniform Traffic Control Devices (MUTCD)and the King’s Highway Guide Signing PolicyManual (KHGSPM).

The Ontario Traffic Manual is directed to its primaryusers, traffic practitioners. The OTM incorporatescurrent best practices in the Province of Ontario. Theinterpretations, recommendations and guidelines inthe Ontario Traffic Manual are intended to providean understanding of traffic operations and theycover a broad range of traffic situations encounteredin practice. They are based on many factors whichmay determine the specific design and operationaleffectiveness of traffic control systems. However, nomanual can cover all contingencies or all casesencountered in the field. Therefore, field experienceand knowledge of application are essential indeciding what to do in the absence of specificdirection from the Manual itself, and in overridingany recommendations in this Manual.

The traffic practitioner’s fundamental responsibility isto exercise engineering judgement and experienceon technical matters in the best interests of thepublic and workers. Guidelines are provided in theOTM to assist in making those judgements, but theyshould not be used as a substitute for judgement.

Design, application and operational guidelines andprocedures should be used with judicious care andproper consideration of the prevailingcircumstances. In some designs, applications, oroperational features, the traffic practitioner’sjudgement is to meet or exceed a guideline while inothers a guideline might not be met for soundreasons, such as space availability, yet still produce adesign or operation which may be judged to be safe.Every effort should be made to stay as close to theguidelines as possible in situations like these, todocument reasons for departures from them, and tomaintain consistency of design so as not to violatedriver expectations.


Ontario Traffic Manual • December 20072

Custodial Office

Inquiries about amendments, suggestions orcomments regarding the Ontario Traffic Manual maybe directed to:

Ontario Traffic Manual CommitteeMinistry of Transportation OntarioTraffic Office301 St. Paul Street, 2nd FloorSt. Catharines, OntarioL2R 7R4

Telephone: (905) 704-2960Fax: (905) 704-2888E-mail: [email protected]

A user response form is provided at the end of Book 1.Inquiries regarding the purchase and distribution of theOTM Books and the Master Sign Library (MSL) may bedirected to the custodial office identified above, or tothe OTM Committee’s current publishing agent.

Inquiries specific to Book 19 (Advanced TrafficManagement Systems) can be directed to the LeadOffice for this book as shown below:

Advanced Traffic Management SectionMinistry of Transportation Ontario1201 Wilson Ave., 6th Floor, Building DDownsview, OntarioM3M 1J8

Telephone: (416) 235-3798Fax: (416) 235-4097E-mail: [email protected]

Book 19 (Advanced Traffic Management Systems) wasdeveloped with the assistance of a Technical AdvisoryCommittee organized by the Ministry of TransportationOntario.

Acknowledgements

Project Consultant Team

Tim Schnarr, Delcan Corporation

Lorita Wong, Delcan Corporation

Simon Lau, Delcan Corporation

Ron Stewart, IBI Group

Anna Dybka, IBI Group

Maryann Lovicsek, IBI Group

Milton Harmelink, Dillon Consulting Limited

Rodney Edwards, Harpar Management Corporation

Suzanne Rodenkirchen, Green Leaf Communications

Technical Advisory Committee

Ataur Bacchus, ITS Section, Ministry of TransportationOntario

Dave Banks, Transportation Engineering, RegionalMunicipality of Waterloo

Jim Bell, Regional Municipality of Ottawa-Carlton andMunicipal Engineers Association

Wayne Bell, Central Region East, Ministry ofTransportation Ontario

Steve Birmingham, Central Region West, Ministry ofTransportation Ontario

Nick Buczynsky, Traffic Office, Ministry ofTransportation Ontario

Harold Doyle, Traffic Office, Ministry of TransportationOntario

Stephen Erwin, ITS Section, Ministry of TransportationOntario

Martin Maguire, Transportation Services, City ofToronto

Philip H. Masters, Advanced Traffic ManagementSection, Ministry of Transportation Ontario

John Proctor, Central Region West, Ministry ofTransportation Ontario

Randy Sanderson, Road Safety & Motor VehicleRegulation, Transport Canada

Lizuarte Simas, Traffic Control Systems, RegionalMunicipality of York

Felix Tam, Advanced Traffic Management Section,Ministry of Transportation Ontario

Bruce Zvaniga, Transportation Services, City of Toronto

2



Table of Contents

1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.1 Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.2 Purpose and Scope . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

1.3 History of ATMS in Canada . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

2. Advanced Traffic Management Systems Overview . . . . . . . . . . . . . . . . . . . . 11

2.1 Information Collection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.1.1 Roadway Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

2.1.2 Probe-Based Sensors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13

2.2 Surface Street Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

2.3 Highway Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

2.4 Regional Traffic Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.5 Traffic Information Dissemination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

2.6 Special Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

3. Planning for ATMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3.1 Identification of Existing Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3.1.1 Description of Roadway Geometry . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3.1.2 Operating Characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

3.1.3 Incidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

3.1.4 Ontario Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.2 Prediction of Future Traffic Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.2.1 Level of Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

3.2.2 Collision Experience . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24


3.3 Identification of Needs and Problems, Existing and Future . . . . . . . . . . . . . . . . . 25

3.3.1 Geometric Constraints . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

3.3.2 Network Operating Conditions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26



3.3.3 Incidents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

3.3.4 Environmental Concerns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.3.5 Stakeholder Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.3.6 Other Factors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.3.7 Development of Consolidated Problem and Needs Statement . . . . . . . . . . 27


3.4 Establishment of ATMS Goals and Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

3.4.1 Increase Capacity and Operational Efficiency . . . . . . . . . . . . . . . . . . . . . . . . . 28

3.4.2 Increase Productivity for Commercial Vehicles . . . . . . . . . . . . . . . . . . . . . . . . 28

3.4.3 Improve Safety . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

3.4.4 Increase Traveller Comfort and Convenience . . . . . . . . . . . . . . . . . . . . . . . . . 28

3.4.5 Improve Public Transportation Services and Operations . . . . . . . . . . . . . . . 28

3.4.6 Improve Cooperation Amongst Transportation Operators . . . . . . . . . . . . . . 28

3.4.7 Reduce Environmental and Energy Impacts . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3.4.8 National Context . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29

3.4.9 Performance Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29


3.5 Review of Network Requirements and Plans . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30

3.5.1 Coordination of Diversion Route Management . . . . . . . . . . . . . . . . . . . . . . . 30


3.6 Selection of Appropriate Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

3.6.1 Incident Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

3.6.2 Congestion Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

3.6.3 Corridor Management and Network Management . . . . . . . . . . . . . . . . . . . . 35

3.6.4 Travel Demand Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

3.6.5 Summary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38

3.7 Identification of ATMS Subsystems and Components . . . . . . . . . . . . . . . . . . . . . 39

3.7.1 Mapping Subsystems to Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.7.2 Subsystem Descriptions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

3.8 Project Implementation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

3.9 Determination of Recommended Solutions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

4. ATMS Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4.1 Information Collection (Real-time Data) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4.1.1 Vehicle Detection System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

4.1.2 Detector Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44

4.1.3 Future Trends . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54



4.1.4 Standards/Interoperability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

4.1.5 Incident Detection Algorithms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55

4.1.6 Closed Circuit Television Monitoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

4.1.7 Call Boxes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61

4.1.8 Vehicle Probes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62

4.1.9 Patrol Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

4.1.10 Private Citizen Calls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

4.1.11 Information from Other Agencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

4.1.12 Advanced Road Weather Information Systems (ARWIS) . . . . . . . . . . . . . . . . 66

4.2 Surface Street Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66

4.2.1 Control Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67

4.2.2 System Types . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68

4.2.3 Design Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69

4.2.4 Lane Control Signs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70

4.3 Highway Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

4.3.1 Ramp Metering System (RMS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72

4.3.2 Access Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

4.4 Regional Traffic Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

4.4.1 Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 76

4.4.2 Centre-to-Centre Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

4.4.3 Technologies and Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

4.4.4 Integration of Legacy Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77

4.5 Traffic Information Dissemination . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

4.5.1 Pre-Trip . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78

4.5.2 In-Vehicle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79

4.5.3 Roadside Dynamic Message Signs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

4.5.4 Role of Private Value-Added Service Providers . . . . . . . . . . . . . . . . . . . . . . . . 82

4.6 Computer System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

4.6.1 System Architecture Functional Requirements . . . . . . . . . . . . . . . . . . . . . . . . 83

4.6.2 Software Functional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 83

4.6.3 Other Functional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

4.6.4 Urban Traffic Control Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86

4.7 Communications System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

4.7.1 Transmission Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87

4.7.2 Transmission Media . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91

4.7.3 Supplementary Communications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95



5. Special ATMS Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

5.1 Bridge/Tunnel Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

5.1.1 High Wind Warning Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

5.1.2 Overheight/Overweight Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96

5.1.3 Noxious Fume Detection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 97

5.1.4 Lane Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

5.1.5 Traffic Control for Lift Bridges . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

5.2 Smart Work Zones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

5.2.1 Portable Variable Message Signs (PVMSs) . . . . . . . . . . . . . . . . . . . . . . . . . . . 98

5.2.2 Highway Advisory Radio (HAR) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99

5.2.3 Traveller Information Telephone Lines and Websites . . . . . . . . . . . . . . . . . . . 99

5.2.4 Radar – Speed Display Signs (Speed Trailers) . . . . . . . . . . . . . . . . . . . . . . . . . 99

5.2.5 Queue Warning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

5.2.6 Roadway Information/Monitoring Systems . . . . . . . . . . . . . . . . . . . . . . . . . . 100

5.2.7 Merge Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100

5.2.8 Work Zone Intrusion Alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

5.3 Queue Warning at Border Approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 101

5.4 Rural Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103

5.5 Enforcement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104

6. Institutional and Management Considerations . . . . . . . . . . . . . . . . . . . . . . . . 105

6.1 Operations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

6.2 Traffic Operation Centres . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

6.2.1 Functional Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105

6.2.2 Spatial Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108

6.2.3 Proximity Relationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110

6.2.4 Traffic Operation Centre Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 111


6.3 Interaction with External Agencies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

6.3.1 Centre-to-Centre . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

6.3.2 Incident Management Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112

6.3.3 The Role of ATMS in Incident Management Plans . . . . . . . . . . . . . . . . . . . . 116

6.3.4 ATMS Roles in Disaster Command and Control . . . . . . . . . . . . . . . . . . . . . . . 118

6.3.5 Coordination of Planned Special Events . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 119

6.4 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120



6.5 Legal Issues . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120

6.5.1 Liability . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

6.5.2 Privacy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

6.5.3 Intellectual Property . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

6.5.4 Procurement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122


7. Evaluation of ATMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1 Overview of Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1.1 Benefit-Cost Analysis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1.2 Performance Rating Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1.3 Linear Scoring Function Tables . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1.4 Incremental Analysis Technique . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123

7.1.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

7.2 Measures of Effectiveness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 124

7.3 Evaluation and Ongoing Bench-Marking . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125

7.3.1 Quality of Service Evaluation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

7.3.2 Communications System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126

8. Integration with Other Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128

8.1 ATMS Integration with Traveller Information Services (ATIS) . . . . . . . . . . . . . . 129

8.2 ATMS Integration with Advanced Road WeatherInformation Services (ARWIS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

8.3 ATMS Integration with Advanced Public Transport Services (APTS) . . . . . . . . 130

8.4 ATMS Integration with Electronic Payment Services . . . . . . . . . . . . . . . . . . . . . . 131

8.5 ATMS Integration with Commercial Vehicle Operations (CVO) . . . . . . . . . . . . . 131

8.6 ATMS Integration with Emergency Management Services . . . . . . . . . . . . . . . . . 132

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

Appendix A • Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 141

Appendix B • References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147



List of Tables

Table 1 – ATMS Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Table 2 – Mapping of Subsystems to Strategies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Table 3 – Summary of Traffic Detectors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46

Table 4 – Summary of Example of RESCU Incident Detection . . . . . . . . . . . . . . . . . . . . . . . 58

Table 5 – Summary of Land-Line Technologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 93

Table 6 – Roles of Emergency Response and Related Agencies . . . . . . . . . . . . . . . . . . . . . . . 114

Table 7 – Example Incident Severity Level Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 115

Table 8 – Example Emergency Agency Response Matrix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116

Table 9 – Typical Measures of Effectiveness (MOEs) for ATMS . . . . . . . . . . . . . . . . . . . . . . . 125

List of Figures

Figure 1 – Historical Traffic Growth on Highway 401 at Keele Street . . . . . . . . . . . . . . . . . . . 25

Figure 2 – Typical Cabinet Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Figure 3 – Typical Inductive Loop Arrangement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

Figure 4 – Typical Image from VID . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Figure 5 – Microwave Detection Unit (Side-Fire Mode) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Figure 6 – Example of RESCU Incident Detection Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57

Figure 7 – Typical CCTV Camera Types for COMPASS ATMS . . . . . . . . . . . . . . . . . . . . . . . . . 59

Figure 8 – Champlain Bridge Lane Control Signs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Figure 9 – Thorold Tunnel Lane Control Signs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Figure 10 – Jarvis Street Lane Control Signs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71

Figure 11 – Signals for Ramp Metering . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74

Figure 12 – MTO Overhead Gantry-Mounted DMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 81

Figure 13 – MTO Roadside-Mounted (Cantilever) DMS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82

Figure 14 – Pamphlet of Road Reports for both MTO and City of Toronto . . . . . . . . . . . . . . . 99

Figure 15 – Typical Elements of a Queue Warning System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Figure 16 – Locations of QWS in Ontario . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102

Figure 17 – Basic Proximity Relationships . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110



1. Introduction

1.1 Background

For many years, the two primary traffic manualsused in Ontario were the Ontario Manual of UniformTraffic Control Devices (MUTCD) and the King’sHighway Guide Signing Policy Manual (KHGSPM).In recent years, the Ministry of TransportationOntario (MTO) has been moving away from directservice delivery, towards a role of servicemanagement with service delivery provided byothers, including the private sector andmunicipalities. As a result, traffic management andthe design and implementation of traffic controldevices are becoming the direct responsibility of agreater number of governing road authorities or theiragents. This includes new players in the field withvarying degrees of knowledge and expertise. Thisnew direction has prompted the need to move awayfrom the reference manuals of the past, towards amore comprehensive user’s manual.

1.2 Purpose and Scope

Book 19 (Advanced Traffic Management Systems)is one of a series of volumes that makes up theOntario Traffic Manual (OTM). Book 19 should beread in conjunction with Book 1 (Introduction to theOntario Traffic Manual) and its appendices, whichcontain essential information on the fundamentalprinciples and policies behind the design andapplication of traffic control signs, signals, markingsand delineation devices. Applicable Ontarioexperience has also been provided to illustratecurrent practices within the Province of Ontario.

This Ontario Traffic Manual, Book 19, providesinformation about the planning, design, installationand operation of ATMS and incorporates relevantoperational guidelines and technical standards. It isintended for use by both the experienced practitioneras well as the newcomer to the field. Book 19

therefore presents a greater amount of informationwith respect to practical guidance, engineeringprinciples and application details than containedwithin previous manuals. The book explains not justthe “what to do” aspects, but also the “why”, interms that will lead the reader to think carefullyabout relevant considerations and the choices to bemade, in order to reach the best decision for thegiven circumstance. Book 19 serves as a practicaland useful user manual instead of purely a referencemanual and is available for use by the traffic andtransportation community within Ontario, NorthAmerica and the world.

It is assumed that the readers of the OTM have abasic understanding of traffic engineering principles.

1.3 History of ATMS in Canada

Canada is a leader in Advanced TrafficManagement Systems (ATMS) with many pioneeringefforts that have taken place in Ontario and acrossthe country. The world’s first computerized trafficsignal management system commenced operationin Toronto in 1959. Freeway traffic managementsystems (FTMS) also have a history in Toronto withthe first implementation of the COMPASS system(FTMS) initiated in 1975 in the Queen ElizabethWay (QEW) corridor through Mississauga. Sincethen, COMPASS has been expanded to several keyhighway corridors where it now manages over 190centreline kilometres of freeway including the QEWin Mississauga and Burlington, Highway 401 acrossToronto and Highway 417 in Ottawa. Based on thesuccesses of these initial installations, ATMSdeployment has expanded across the country. Today,ATMS continues to be a major focus in managingthe nation’s transportation networks with systemsbeing deployed throughout the country.



Highlights of some of the more significant ATMSachievements in Ontario are listed below:

1959 World’s 1st experiment in computerizedtraffic control for the City of Toronto

1964 World’s 1st full-scale traffic signal systemusing digital computer technology for theCity of Toronto

1975 Field tests of real-time control of trafficsignals in the City of Toronto

1975 COMPASS freeway traffic managementsystem (FTMS) for the QEW in Mississauga

1976 Canada’s second centralized traffic signalsystem in the City of Ottawa

1978 World’s 1st second-generation traffic signalsystem in the City of Toronto

1982 Computerized traffic signal control availablefor smaller municipalities

1985 Canada’s 1st corridor management system(COMPASS) implemented on the QEW inBurlington, Ontario

1990 Canada’s first PC-based centralized trafficsignal system implemented in the City ofOttawa

1991 COMPASS on Highway 401 in Toronto,North America’s 1st freeway trafficmanagement system (COMPASS) to utilizean all fibre optic communications system andamber-coloured LED variable message signs

1992 First SCOOT demonstration in City of Toronto

1994 Start of operation of the City of Toronto’sRESCU FTMS system on the GardinerExpressway, Lake Shore Boulevard and DonValley Parkway

1995 SCOOT system in Toronto, now 3rd largestinstallation in the world

1995 Combo smartcard implemented for the publictransportation system in Burlington, Ontario

1996 Ministry of Transportation Ontario as partnerin the AURORA consortium of U.S., Canadianand European highway agencies, promotescollaborative research, development anddeployment of advanced road weatherinformation systems (ARWIS)

1996 Use of CCTV cameras in City of Ottawa tomonitor arterial roads and supplement trafficsignal management

1997 World’s 1st all-electronic open road tollingsystem, fully accessible to general public –407 Express Toll Route (407 ETR)

1999 Total conversion of Toronto SCOOT to version7 software and decommissioning of originalSCOOT computer systems

2003 Implementation of cellular communications(GSM/GPRS) for City of Ottawa’s trafficsignal system

2003 Operation of Canada’s 1st Queue WarningSystem (QWS) along General Brock Parkway(previously known as Highway 405) andQEW on the approaches to the U.S.international border in the Niagara Region

2004 Operation of an incident detection andAdvance Warning Sign (AWS) System for theHigh Occupancy Vehicle Bypass Tunnel atthe Highway 404/401 Interchange

2007 Operation of a QWS along Highway 402 onthe approaches to the U.S. internationalborder in Sarnia



The concepts and objectives of ATMSs areintroduced and discussed throughout this documentunder the following five categories:

• Information Collection• Surface Street Control• Highway Control• Regional Traffic Control• Traffic Information Dissemination• Special Applications

Detailed descriptions of each category are providedin Section 2 of this document.

2. Advanced TrafficManagement SystemsOverview

Intelligent Transportation Systems (ITS) is theapplication of technology to better manage thetransportation network. More specifically, theIntelligent Transportation Systems Society of Canada(ITS Canada) has defined ITS as:

“the application of advanced and emergingtechnologies (computers, sensors, control,communications, and electronic devices) intransportation to save lives, time, money, energy andthe environment.”

The goal of ITS in road transport is to achieveimprovements in mobility, safety, and the productivityof the transportation system through the integratedapplication of advanced monitoring,communications, computer, display, and controlprocess technologies, both in the vehicle and on theroad. Under the umbrella of ITS, Advanced TrafficManagement Systems (ATMS) have proven to beone of the most successful components inaccomplishing these objectives. This sectionprovides an overview of the types of systems andfunctionality that can be provided through AdvancedTraffic Management Systems.

Under the ITS Architecture for Canada, TrafficManagement is one of the eight user-servicebundles. The primary focus of OTM Book 19 is theTraffic Control user service contained within thisbundle. For more information on the ITS Architecturefor Canada and the related user services, the readeris referred to Transport Canada’s website(www.its-sti.gc.ca/Architecture/).



2.1 Information Collection

Strategic traffic management and control requiresinformation about the operational state andcharacteristics of traffic flow. The parameters mostrelevant to ATMS include:

• Traffic Flow or Volume – the number of vehiclespassing a point per unit of time;

• Vehicle Speed – the distance travelled by a vehicleper unit of time, usually expressed in km/h;

• Traffic Density – the number of vehicles occupyinga road lane per unit of length at a given point intime;

• Occupancy – similar to traffic density, usuallyexpressed as a percentage representing thepercentage of time a detection zone on the road isoccupied;

• Incident – an unplanned event that occurs within aroadway (on the travelled portion, shoulder orroadside) that impacts the capacity of theroadway. Relevant details of an incident includedate/time, location, direction of travel, type ofimpact, class of collision (fatal, personal injury,property damage), weather condition, road surfacecondition, number of vehicles involved, number oflanes blocked, etc.; and

• Weather Conditions – relevant details on currentweather conditions, such as wind speed, humidity,temperature, visibility, etc.

To measure these parameters, many different typesof detectors/sensors are available, includingroadway sensors and vehicle probes. Part of thechallenge of information collection is to gatherinformation that is both accurate and relevant fortraffic management purposes, and current enoughto be useful.

2.1.1 Roadway Sensors

Roadway sensors can be divided into severalcategories: embedded or intrusive (i.e., embedded inthe pavement), non-intrusive (i.e., installed off thepavement), and environmental. The following is a listof the more commonly used sensors:

Embedded (Intrusive) Detectors

• Inductive Loop – An Inductive Loop Detectorconsists of a copper wire embedded in the roadsurface in the shape of a loop (e.g., square,rectangular, diamond, etc.). Passing an electricalcurrent through the copper wire induces amagnetic field in the vicinity of the loop. Typically,a loop will consist of three to five “turns” of copperwire in the ground. Connecting the loop to aroadside cabinet through a lead-in cable allowselectronic equipment to monitor the magnetic fieldand changes in inductance as a vehicle passesover the loop.

• Magnetometer – Magnetic detectors are littlepencil-shaped/cylindrical probes, placed verticallyin or beneath the road surface. They measurechanges in the earth’s magnetic field as a vehiclepasses over them.

Non-Intrusive Detectors

• Radar – Radar detectors actively emit radio wavesignals and can register vehicular presence andspeed, depending upon the characteristics of thesignal returned to them by the moving vehicles.Currently, there are two types of radar detectors:Doppler, which measure the change of frequencybetween the transmitted and received signals, andTime of Flight, which measure the difference intime between when the signal is transmitted andreceived.



• Infrared – Infrared detectors send out invisibleinfrared radiation pointed at the road surface. Bycomparing the radiation reflected from a passingvehicle with the radiation from the road surface,the sensor can detect the presence of a vehicle.

• Ultrasonic – Ultrasonic detectors emit continuous(Doppler) or short interval (Pulsed) signals directedto the road surface. The Doppler detectormeasures the shifts in frequency of signalsreflected by passing vehicles to detect anddetermine their speeds. The Pulsed detectormeasures the time taken by reflected signals toreturn to the sensor.

• Acoustic – Acoustic detectors use microphonesand signal processing technology to listen forsounds made by passing vehicles to determine thepresence of a vehicle.

• Video Image Processing (VIP) – Video imageprocessing utilizes images provided by videocameras installed near the roadway. “MachineVision” algorithms are combined withcomputerized pattern recognition software todetect passing vehicles.

• Closed Circuit Television (CCTV) Cameras – CCTVcameras are used to monitor traffic flowconditions and verify traffic congestion andincidents. Typically, CCTV cameras provide visualimages to aid operations centre personnel indetermining and verifying causes of congestion,such as collisions, vehicle breakdown, load spills,construction/maintenance activities, police/fireoperations, or just heavier than normal traffic.

Environmental Sensors

• Atmospheric Sensors – measure a variety ofweather-related data, including wind speed anddirection, air temperature, humidity, precipitationoccurrence/accumulation and visibility. Videoimages can also be utilized to confirm conditions(e.g., precipitation, visibility, etc.).

• Road Surface Sensors – measure road surfacetemperature as well as ascertain a variety ofinformation with respect to the road surface suchas wet or dry, presence of chemicals (e.g., anti-icing, de-icing, etc.), presence of snow, ice orfrost, etc.

• Sub-surface Sensors – measure the temperatureat different depths in the substrate directly belowthe roadway.

2.1.2 Probe-Based Sensors

Probe-based sensors measure the movement of apercentage of the vehicles in the traffic stream inorder to assemble real-time traffic information.Probe-based monitoring can be a very effectivemethod of data collection for wide area monitoringwhere large geographic areas are involved. Probe-based sensors typically provide measurements onlink speeds, link travel times, and origin anddestination of vehicles travelling through thetransportation system. The following is a list of themore commonly used probe-based sensors:

• Vehicle Probes – Vehicles equipped with on-boardunits that allow the time and location of thevehicle to be tracked using Automatic VehicleIdentification (AVI) or Automatic Vehicle Location(AVL) devices. Examples of commonly useddevices include Global Positioning Systems (GPS)for AVL such as those used for monitoring ofcommercial vehicle fleets and E-ZPasstransponders for AVI purposes, used throughoutthe Northeastern United States for electronic toll



collection purposes. Cellular telephones can alsobe used for this purpose where the handset islocated using either GPS or through informationcollected via the cellular transmission towers.

• Mobile Reports – Traditionally, emergencytelephones (i.e., call boxes) installed alongroadside facilitates have been used to reporttraffic problems to a traffic operations centre.However, with the proliferation of cellulartelephones in recent years, the use of call boxeshas significantly reduced. Instead, mobilereporting from patrol vehicles and private citizencalls through toll-free hotlines has become avaluable resource for quick detection of incidentsand collection of traffic and incident information.This system has the advantage of low start-upcost and two-way communications between thecaller and the response agency. It can, however,cause a high volume of calls when a majorincident occurs. Also, it is sometimes difficult toverify the location of an incident when calls arereceived from private callers.

• Designated Spotters – Designated vehicles can beutilized to act as vehicle probes and/or as spottersfor traffic incidents. These vehicles can be selectvehicles from a government agency fleet (e.g.,road maintenance, service patrol, etc.) or vehiclesof regular commuters.

2.2 Surface Street Control

Surface Street Control refers to the monitoring,control and management of traffic operations onmunicipal streets and arterials. The primaryapplication of ITS within Surface Street Control isthe management of signalized intersection controland the assignment of right-of-way for all users ofthe transportation network including vehicles (e.g.,passenger cars, trucks, transit vehicles, emergencyresponse vehicles, maintenance vehicles, etc.),cyclists and pedestrians. This section describes

surface street control systems from a networkperspective addressing signal coordinationtechniques, system types and vehicle prioritysystems. A range of traffic signal control systemsare represented ranging from static pre-timed controlsystems to fully traffic-responsive systems thatdynamically adjust control plans and strategiesbased on current traffic conditions and priorityrequests. For a more detailed discussion on theoperational aspects of traffic signals (e.g., signalphasing, timing, vehicle actuation, etc.), the readeris referred to OTM Book 12 (Traffic Signals). Theremainder of the traffic signal information in thisbook refers to the operation of groups of signals insystems.

The major objectives of Surface Street ControlSystems are to:

• Maximize the capacity of the existing roadnetwork through the optimization of traffic signaloperation;

• Improve safety for all road users, includingvehicles, cyclists and pedestrians;

• Reduce delays, stops and fuel consumptionassociated with the operation of traffic signals forall road users;

• Monitor the operation of traffic signal equipmentand report malfunctions to minimize equipment“down time” and maximize maintenanceefficiency; and

• Monitor traffic conditions and collect real-timetraffic data.



A typical Surface Street Control System consists ofintersection control equipment (i.e., intersectioncontroller, signal heads, etc.), detection equipment(i.e., vehicle detector, pedestrian detector, bicycledetector, etc.), communications network and acomputer system to provide central control andmonitoring functions of the field equipment.

Multiple Surface Street Control Systems in a regionshould be capable of sharing data with each otherelectronically. The objective of this informationexchange is to allow adjacent jurisdictions to providearea-wide signal coordination along major corridorsand road networks regardless of jurisdictionalboundaries.

The primary objective of a traffic signal is to safelyassign right-of-way to vehicles, cyclists andpedestrians all competing for the use of the sameroad space at intersecting roadways. Typically, this isachieved using intersection control equipment withright-of-way assigned, based on the presence ofvehicles, pedestrians and bicycles. Prioritiesbetween road users and vehicle types can vary, andfor this reason many traffic signal systems offer amethod of providing priority service to accommodatetransit vehicles, emergency response vehicles andoperation of at-grade rail crossings located in closeproximity to signalized intersections. Both local andcentralized methods of priority control are available.

A secondary application of ITS within Surface StreetControl is lane management, which involves therestriction of specific lanes of a roadway todesignated vehicle types, direction of travel or otherpurposes. It involves the use of lane control signs(LCSs) and a central control and monitoring system.Lane management systems are commonly used forreversible lane operation on urban arterials as wellas bridges and tunnels, for high occupancy vehicle(HOV) / high occupancy toll (HOT) lanemanagement, and have also been applied for trafficmanagement purposes through construction zones.Typically, they are applied to traffic bottlenecks

where roadway expansion is difficult due to right-of-way or cost restrictions. Their primary objective is tomaximize the capacity of existing roadwayinfrastructure for specific vehicles or to alter adirection of travel.

2.3 Highway Control

Highway Control uses roadside equipment andcommunications to monitor traffic conditions on thehighway network for traffic management, incidentdetection and management, ramp metering andaccess control. Typically, it is applied to high-volume,access-controlled highways located within or inclose proximity to large population centres.

Highway control employs monitoring techniques andadaptive control strategies to maximize theefficiency of traffic movement and better managetraffic congestion.

It is widely recognized that the occurrence of anincident and the resultant blockage of travel lanesand/or shoulders has a dramatic effect on thecapacity of the roadway. It therefore follows that thefaster an incident can be cleared the less impact itwill have on the operation of the highway network.Incident management refers to the timely detectionof incidents and the dissemination of relevantinformation to emergency response agencies,maintenance personnel, traffic management staffand motorists in order to minimize the duration andimpact of the incident on the transportation network.

Ramp metering and access control is the applicationof control devices such as traffic signals, signingand gates to regulate the rate of vehicles enteringthe freeway. In general, the primary focus of rampmetering and access control is to reduce congestionand the associated delays on the mainline, with theobjective of balancing demand and capacity of thefreeway.



2.4 Regional Traffic Control

Regional Traffic Control enhances the SurfaceStreet Control and Highway Control by adding thecommunications links and integrated controlstrategies that enable integrated inter-jurisdictionaltraffic management. Regional traffic control can beapplied to a freeway/arterial corridor consisting of afreeway, arterial road or combination of both. Atypical Regional Traffic Control System consists oftraditional traffic control such as regulation, warningand guidance of traffic, as well as freewaymanagement activities such as vehicle monitoring,incident detection and management, provision ofmotorist assistance and traffic informationdissemination. The major objectives of RegionalTraffic Control Systems are to:

• Monitor traffic flow and other environmentalconditions on the freeway/arterial corridor;

• Reduce delays and collision risks due to non-recurrent congestion through rapid detection andappropriate management of incidents;

• Determine and identify actions to alleviaterecurrent congestion;

• Disseminate information to motorists about thefreeway/arterial corridor condition to improvesafety and mobility, and enable diversion; and

• Maintain the freeway/arterial corridor at anoperating level by efficient implementation oftraffic control strategies (including ramp metering,active/passive diversions, etc.).

While the objectives and functions of differentRegional Traffic Control Systems may be similar,each system is a unique combination of subsystems,policies and procedures, and agency interfaces thatreflect the location-specific requirements of thefreeway/arterial corridor and its geographic area.

2.5 Traffic Information Dissemination

Knowledge of traffic and roadway conditionsprovides travellers advance warning of unusualconditions ahead and allows drivers the opportunityto alter their route or the timing of their trip. TrafficInformation Dissemination addresses the ways bywhich timely and accurate traffic information isconveyed through the media, via traveller accessdevices such as the internet, personal digitalassistants, phone, e-mail, pagers, in-vehicle devices,etc., or through the use of roadway equipment suchas dynamic message signs. It also addresses theequipment and interfaces that provide informationfrom a traffic operations centre to other operationscentres (e.g., transit management centre,emergency service dispatch centre, etc.) or otheragencies, for wider dissemination (e.g., media,information service providers, etc.).

Considerable research has been done over the past30 years relating to human factors issuesassociated with the dissemination of trafficinformation through dynamic message signs.Although technologies have changed and willcontinue to change in the future, this research hasidentified several fundamental factors that influencethe effectiveness of dynamic sign displays,independent of the technology used. These factorsshould govern the size, location, displaycharacteristics and message content of signdisplays.

The effectiveness or usage of signs depends on thefollowing factors:

• Conspicuity – Does the sign attract attention giventhe environment in which it is placed?

• Legibility – At what distance can drivers read thesign?

• Information Load – Do drivers have sufficient timeto read the entire message without undulydiverting their attention from the driving task?



• Comprehension – Do drivers understand themeaning of the message and any symbols orabbreviations used?

• Driver Response – Do drivers make the desiredaction as a result of reading the sign?

Additional information about these factors and howthey affect sign design and the driver’s ability tosafely navigate within the traffic stream may befound in OTM Book 1b (Sign Design Principles), andin OTM Book 2 (Sign Design, Fabrication andPatterns). It should be noted that although the basicdesign principles apply to all signs, some of thespecific information and comments presented inBook 1b are only applicable to static signing.

For additional information on dynamic messagesigns, human factors, and how they affect signdesign, the reader should refer to OTM Book 10(Dynamic Message Signs).

2.6 Special Applications

In addition to the ITS applications discussed above,there are several special applications for ATMSs thatare discussed in further detail in Section 5. Theseare as follows:

• Tunnel/Bridge Management – due to the uniquecharacteristics and physical constraints of bridgesand tunnels, ATMS applications specific to thesefacilities are discussed separately. Theseapplications include:

– High Wind Warning System – to providewarning to motorists of the presence of highwinds and any traffic management responseplan in effect;

– Swing Bridge Warning System – to provideadvanced warning to motorists when a swingbridge is closed to vehicular traffic, providingthe opportunity to divert to an alternate route;

– Overheight/Overweight Detection – to detectthe presence of overheight/overweight vehiclesand provide motorists warning in order toprevent damage to a tunnel or overpass;

– Noxious Fume Detection – to detect the build-upof noxious fumes from vehicle exhaust inside atunnel and implement appropriate responseplans; and

– Lane Management – to close one or more laneswith use of signals, gates, etc.

• Smart Work Zones – to provide motorists withinformation on construction, speed managementand/or detours with the objective of improvingmotorist and worker safety.

• Queue Warning at Border Approaches – to detectslow-moving traffic and provide motorists advancewarning of queue conditions.

• Rural Application – to implement ATMS in ruralareas that focus on the improvement of safety andminimizing the impact of environmentalconditions.

• Enforcement – to utilize ATMS-relatedtechnologies to monitor compliance and helpenforce traffic regulations.



3. Planning for ATMS

A structured approach to the planning of ATMSdeployment is important in order to rationalize ATMSrelative to other competing transportation investmentoptions, and to ensure the quality, integrity andaccountability of the program. The planning processis equally relevant to agencies embarking on a newATMS program as well as agencies expandingexisting systems. The planning process starts with areview of traffic conditions leading to a statement ofneeds and objectives. Candidate system strategiesare assessed and prioritized in consideration of theseobjectives to yield a definition of systemrequirements and project scope. Systems aredefined at the component level based upon a reviewof the current state of enabling technologies andfuture technology trends.

This section provides a logical approach to guide thereader through the various planning steps for theimplementation of advanced traffic managementsystems. The planning process will ensure thatprojects are implemented cost-effectively, meetestablished needs and priorities, and take intoconsideration budgetary constraints as well as otherfunding concerns and/or opportunities.

3.1 Identification ofExisting Conditions

Advanced Traffic Management Systems are oftendeveloped to help mediate recurrent and non-recurrent congestion problems as well as to reducethe frequency of collisions. In order to determine ifan ATMS is the correct solution for a particularproblem, it is necessary to accurately define theproblem. There are a number of methods of definingcongestion and collision characteristics, all of whichrequire collection of a significant amount of fielddata. A thorough description of roadway geometry,operating characteristics and incidents is required.

This information will help to determine the need foran ATMS, help the agency develop operationalstrategies, and assist in the selection of theappropriate type and location of ATMS components.

3.1.1 Description of Roadway Geometry

A description of existing physical road networkconditions is an important component to thedevelopment of an ATMS, as there are differenttraffic management strategies that can beimplemented on different classes of roads. Inaddition, geometric layout and physical location ofintersections/interchanges can impact the choice ofstrategies that will be deployed. Therefore, adetailed description of the study area is required.The description should include:

• Location of alternate routes and their capacities;

• Number of lanes and their capacities (includingturning lanes if applicable);

• Horizontal and vertical alignment;

• Number, type, location and spacing ofinterchanges/intersections;

• Width and type of shoulders;

• Median characteristics (divided, undivided andtype of barrier);

• Number and type of overpass/underpassstructures;

• Location of existing traffic system installations(including communications and power facilities);

• Current width of right-of-way (ROW), and potentiallimitations to expand the ROW (if required orplanned);



• Identification of rural versus urban environment;and

• Coverage and type of roadway lighting.

The description of roadway geometry can bedocumented in tabular format and supplementedwith schematic drawings. This inventory of thephysical attributes of the roadway will facilitate thedevelopment of a concept plan with preliminaryequipment layout, assist with the definition ofinstallation requirements and related costs, andhighlight any potential impediments to installation. Itmay also assist in defining the limits and scope ofthe deployment.

3.1.2 Operating Characteristics

Traffic Characteristics

Traffic volume is fundamental data necessary forcapacity calculations and growth forecasting. Trafficvolume profiles by roadway link and by time of dayare necessary to assess traffic volume/capacityrelationships and peak-hour loading. It is importantto distinguish traffic volume profiles to reflectcommuter, seasonal and recreational travel patterns.Relevant information includes vehicle classificationcounts, vehicle occupancy, speed profiles, volumeprofiles and, where applicable, intersection turningmovement counts. This information is typicallydocumented in tabular spreadsheet or databaseformat.

Traffic volume generated by special events orvenues such as entertainment complexes, paradesand sporting events is also of interest. Thesegenerators can introduce a large volume of trafficonto the surrounding network in a concentrated timeperiod. A special event is not necessarily limited to aparticular facility. Large events such as parades candirectly impact a large portion of the road network,including full or partial closures, and generatespecial traffic volume characteristics over

concentrated (several hours) or extended (severaldays) periods of time. Typically, a trafficmanagement plan is developed for these types ofevents, and this information should be included inthe summary of current conditions.

Levels of Congestion

For both urban freeway and arterial networks,congestion is a recurrent feature that is prevalentduring weekday peak periods. It is associated withthe traditional patterns of travel to work in themorning and home again in the evening.

From the perspective of the motorist, longer andmore variable travel times, and lower operatingspeeds are indicators of congestion. For systemdesign purposes, there are two types of trafficvolume parameters that best illustrate the severity ofrecurrent congestion. These are the design hourvolume (DHV) and the peak hour (AM/PM) volumes.The DHV is defined as the 30th highest hourlyvolume experienced during the year and iscalculated using observed data. The peak hourvolumes are normally derived from a relatively smallsample of observations obtained over the peaktraffic periods of a day. This information is typicallydocumented in tabular spreadsheet or databaseformat.

Current DHV data is generally a more realisticreflection of the peak hour traffic volume than theobserved peak hour volumes. This is because thedata used to calculate the DHV is often based onthe distribution of observed hourly traffic volumesover a longer period of time than those observed todetermine the peak hour volumes. Normally, peakhour volumes represent a one-hour volume based ondata taken over several days, and therefore can bemore easily influenced by such factors as weather,incidents, construction, etc.



3.1.3 Incidents

When incidents temporarily reduce roadwaycapacity, the resulting non-recurrent congestionincreases driver delays and frustration, anddecreases safety. An incident is defined as an eventoccurring on the road which reduces roadwaycapacity and causes, or may potentially be a causeof, traffic disruption. Incident rates and collisionfrequencies are developed over a significant periodof time in order to be statistically significant.Incident location, severity and duration information isof particular use. This information is typicallyinterpreted from police records and documented intabular spreadsheet or database format, and can begraphically represented using schematics of theroad network.

Incident Type

There are five main classes of traffic incidents:vehicle collisions, vehicle breakdown, debris, fire/emergency, and other traffic incidents. It isnecessary to determine the frequency of each typeof incident. The following is a brief description ofthese classes:

Vehicle CollisionsThese are significant incidents that may involvevehicles colliding with other vehicles, pedestrians,trains, road furniture, trees, bridge structures or otherphysical features. The incident may be classified aseither non-injury (property damage), injury or fatal.Minor collisions can be moved to off-highwayCollision Reporting Centres by drivers or tow trucks.Police assistance is required at major incidents tomanage traffic flows and to complete the necessaryprocedures. Emergency services requested wouldnormally include towing, ambulance and/or fireservices. These incidents may result in a lane and/or road closure. In the event of an incident, theATMS Traffic Operation Centre can assume a key

response management role, providing information toresponse agencies, implementing area-wide trafficmanagement/diversion strategies, and providingmedia relations and traveller information.

The frequency and rate of collisions must bereviewed by type, severity, roadway section, time ofday, vehicle type, etc. This information can besubjected to off-line analysis in order to help identifyproblem locations or circumstances. Analysis mustalso discriminate between personal injury andproperty damage collisions. In addition to qualitativesocial impacts, the collision analysis can serve tocalculate the economic impacts of collisions.

Vehicle collision frequencies and rates are typicallycalculated using data available from police reportsprepared by the police officer attending a collisionsite, or by motorists at Collision Reporting Centres.Self-reported collision data from motorists isconsidered to be of dubious accuracy. It is importantto note that not all collisions are reported. Accordingto MTO1, police collision data typically do not reflectabout 20% of injuries requiring hospitalization andup to 50% of injuries not requiring hospitalization.Furthermore, it is estimated that 60% of reportableproperty-damage-only collisions are not reported.Existing ATMS are a useful source of incident data,which can be used to help define a correlationbetween total collisions and police collision data.

Vehicle collision rates are generally calculated fordefined roadway links based on the number ofcollisions per million vehicle-kilometres or at anintersection based on collisions per million enteringvehicles. While collision rates have been traditionallyused to evaluate the need for operationalimprovements, including ATMS applications, MTO2

recommends using “collision frequency” (usuallycollisions/year, or collisions/km/year) instead of theaforementioned “collision rate” to evaluate the

1 The Science of Highway Safety – Network Evaluation and Safety Conscious Procedures, MTO Traffic Office, Traffic Safety ManagementSection, 1999.

2 Ibid.



relative safety of a road. Research indicates that therelationship between expected collision frequencyand traffic flow is usually not linear. Therefore, forexample, doubling the vehicle kilometres of traveldoes not double the number of collisions. As a resultof this non-linearity, using the collision rate tomeasure safety can be misleading, if “safety” is tobe used as a tool to evaluate the need to implementan ATMS.

Vehicle BreakdownExamples of vehicle breakdowns could include avehicle that has a flat tire or has run out of gas andcan involve the blockage of the shoulder or a travellane. Typically, in these circumstances, anemergency response vehicle or tow truck wouldrespond and use flashing lights to warn approachingmotorists that there are vehicles broken down orparked within the roadway. However, freewayshoulder blockages and lane-blocking events onsome arterials are considered a low priority to policeand other emergency response services. Roadoperations dispatch centres typically keep records ofthese types of incidents.

Provincial highways in Ontario are maintained byArea Maintenance Contractors (AMC) within theirgiven geographical areas. The AMC emergencyresponse vehicles and/or tow trucks would beinvolved in the removal of vehicles from the travelledportion of the roadway. With vehicles which aremore difficult to tow, such as overturned trucks andloaded vehicles, heavy-duty tow trucks with adequateuprighting, lifting and recovery capability may berequired to assist in incident clearance. Locatingspecialty equipment, transporting it to the site andundertaking clean-up activities can significantlyincrease the duration of the incident and anyassociated lane closure.

DebrisMajor emergencies/disasters may create a largeamount of debris or materials spilled on the roadwaywhich must be cleared as part of the response andrecovery process. In general, MTO’s AMCs would beinvolved in the removal of debris on provincialhighways. The trend is to use an automated debrisrecovery system that allows removal of debris fromthe roadway without stopping or having personnelworking outside the vehicle.

For incidents involving dangerous goods spills, theMinistry of the Environment and Fire Services are tobe notified. Specialized dangerous goodscontractors may have to be mobilized to effect thenecessary clean-up and disposal of toxic orhazardous materials.

Fire/EmergencyThis level of incident often requires that emergencyservices secure the incident scene for safetypurposes. As a result, these incidents result in thepossibility of partial or total road closure. Typically, allemergency services (police, fire, ambulance) wouldbe involved. Secondary traffic measures would beactivated with traffic management required on theadjacent arterial road network. These responseactivities are normally directed by the police service.Road operations dispatch centres typically keeprecords on these types of incidents.

The standard practice is to stage the fire-fightingvehicles behind (upstream) the incident in order toblock lanes for the safety of the incident scene andthe emergency responders. This is done in such amanner that facilitates traffic movement around orthrough the incident scene and minimizes thenumber of lanes closed. The practice of fightingfires from the side, however, may result in additionallanes being closed, or the possibility of totalclosures.



Other IncidentsOther incidents that affect traffic can include severeweather conditions, community evacuations,emergency road maintenance, and any situation orevent, excluding vehicle breakdown or collisions.There are times when police officers responding toan incident of this type may not be directly involvedwith the situation but would assist by providingspecialist services. A good example of this type ofincident is when animals are present on theroadway, having strayed from adjacent properties.Road operations dispatch centres typically keeprecords on these types of incidents.

Incident Duration

Incident duration is defined as the time from theoccurrence of the incident to the clearance of theincident from the roadway. It is incorporated intoeconomic analyses to calculate the delayexperienced by motorists. If known, this durationshould include the time between the occurrence ofthe incident and detection of the incident. It isdifficult to establish the time of incident occurrencewithout CCTV (closed-circuit television) monitoring inplace.

Impact Duration

Impact duration is defined as the time from theoccurrence of the incident to the clearance of theobstruction and return to normal traffic conditions. Itis used for calculating the time that an ATMSoperator would be involved with the incident, andtherefore, important in the calculation of operatorloading.

Each of these measurement categories is to beconsidered in conjunction with various stages of anincident as follows:

• Incident-to-detection• Detection-to-response• Response-to-clearance

• Recovery (i.e., restoration of normal operatingconditions).

Reducing the duration of these stages improvessafety by reducing secondary incidents, reducingvehicle delays and results in savings in vehicleoperating costs as well as reductions in harmfulemissions.

Typical Impacts of Incidents

The severity or degree of incident impact should bequantified, which is often, but not necessarily tied tothe duration of the incident. It should be noted thatadjacent arterial roads experience additional flowsas motorists divert around the incident (on either afreeway or arterial). Also, during incidents,“rubbernecking” is a common occurrence, and as aresult, the traffic lanes in both directions of travelcan experience capacity reductions.“Rubbernecking” can result in secondary incidents ofvarying severity within the affected roadway lanesand on adjacent roadways.

Three levels of impacts are discussed here.

Minor Impact IncidentsMinor incidents are primarily comprised of vehiclebreakdowns, debris, as well as other traffic incidentsand minor vehicle collisions. Typically, they consist ofshoulder closures which result in capacity reductionsin adjacent lanes.

Major Impact IncidentsMajor incidents are comprised of vehicle collisions,debris involving dangerous goods spills, other trafficincidents and fire/emergency incidents. They consistof non-injury, injury and fatal collisions, and typicallyinvolve lane closures and an emergency responseteam involving several agencies. A small number ofmajor incidents can result in full closure of theroadway with motorists being diverted onto other



freeways and the adjacent arterial road network.Major incidents have a large impact on motorists,particularly if they occur during or before the peakperiods.

Headline Impact IncidentsHeadline incidents are normally comprised of vehiclecollisions, debris involving dangerous goods spills,other traffic incidents and fire/emergency incidents.These typically involve fatalities, heavy vehicles andmajor spills. In many cases, these incidents result ina full road closure, but always result in significantdelays to motorists upstream of the incident, andthose on the adjacent parallel arterial roads that actas the diversion route. Headline incidents tend toattract a significant amount of media attention.

3.1.4 Ontario Experience

The collection of data on existing conditions can becumbersome, and can often experience delays.Some typical hurdles that have been experienced inOntario include:

• Mapping which is out of date, or incomplete;

• Traffic volume data which is incomplete, out ofdate, or has been collected on different sections indifferent years, or in different times of the year;

• Collision data which is incomplete and/or includessignificant errors;

• A significant drop in reportable collisions from oneyear to the next – this can be attributed to majorchanges in the process for collision reports, suchas an increase in the property damage dollar valuethreshold for “reportable collisions”; and

• A non-typical traffic pattern resulting from roadconstruction activity.

Ontario experience also indicates that it can behelpful to involve representatives of emergencyservices at the data collection stage of the planningprocess, to provide an opportunity for them tocontribute their observations on problem areas andthe reasons or causes behind them.

3.2 Prediction of FutureTraffic Conditions

In order to plan a new ATMS or expansion to anexisting ATMS, agencies need to be able to definecriteria that trigger deployment. There are twoprimary criteria that can be used. These are level ofservice and collision experience. These two criteriaare performance indicators that reflect the trafficsafety and flow for a particular highway section.

3.2.1 Level of Service

The level of service of a roadway facility is typicallyexpressed in terms of the Volume-Capacity (V/C)ratio. A V/C ratio is listed in the Highway CapacityManual (HCM) as one of the performance measuresthat characterize traffic flow on a roadway section.A V/C ratio approaching 1 (one) for any particularroadway link indicates a problem area and likely abreakdown in traffic flow. Using the HCM, thecapacity of different roadway sections can bedetermined. It should be noted that the capacity of aroadway section will drop due to the occurrence ofincidents and/or the associated effects of“rubbernecking”.

In order to predict the level of service for futuretraffic conditions, the following data is required:

• Number and geometry of lanes on the section ofroadway; and

• Projected traffic volumes for the horizon year.



This information is typically documented in tabularspreadsheet or database format, and can begraphically represented using schematics of theroad network. The number of lanes on a section ofroadway may be confirmed by consulting the capitalworks program of the operating authority. If there areno plans for the section of roadway, the number oflanes will remain unchanged from currentconditions.

If rehabilitation work is planned, there will be lanereductions for the duration of the project. If awidening is planned, there will likely be lanereductions during the project, followed by theopening of additional lanes. If there are plans torehabilitate and/or widen the roadway, the designershould consider the implementation of an ATMS toassist with traffic management in work zones inorder to improve safety and optimize trafficthroughput. Furthermore, the cost of implementationof ATMS infrastructure (e.g., ductwork, pole basesand cabinet bases) is greatly reduced whenimplemented as part of a broader roadwork initiative.

Traffic volume growth rates can be assessed usinghistorical trends in DHV, peak hour and annualaverage daily traffic (AADT) volumes. The operatingagency usually has a transportation planning sectionalready performing traffic volume projections. Thisinformation will provide general background growthrates. The designer should also investigate plans forthe development of significant traffic generators,such as large commercial developments,entertainment complexes and sports facilities thatmight significantly increase traffic volumes atspecific locations. These types of facilities areusually required to submit a “traffic impact study” tothe local planning authority, and the contents ofthese studies will provide valuable input into futuretraffic projections, including capacity constraints,peak periods and peak spreading.

Traffic flow theory indicates that there is a directrelationship between traffic flow and speed. Thisrelationship illustrates that as traffic volumeincreases, traffic density increases reducing spacingbetween vehicles. As density increases, traffic flowalso increases. Traffic, however, will reduce speedas density reaches a critical point which negativelyimpacts traffic flow. The result is that there is anoptimum speed at which traffic flow or the capacityof a facility is maximized. Currently, there is researchunderway which examines this speed/flow curve toestimate the operational speed at which thecapacity of a roadway facility is maximized. Theultimate goal is to be able to predict the degradationof traffic operations (i.e., congestion) on a roadwayor the probability of an incident due to congestionbefore it occurs.

3.2.2 Collision Experience

Trends in historical, year-by-year, average collisionfrequencies or collision rates will form the basis forprojecting future collisions and identify potentialsafety concerns. A review of the data on a section-by-section basis will also identify key roadwaysections where collisions have been relatively high. Itis also important to examine the historical trends incollision frequency, either at a point (interchange orintersection) in collisions/year, or on a section, incollisions/km/year. The economic impacts andcosts of collisions can be extracted from an analysisundertaken by the MTO entitled The Social Cost ofMotor Vehicle Collisions in Ontario (1994).


Anticipating future traffic conditions can be achallenging undertaking, particularly when dealingwith regionally-oriented traffic flows. In completingthis task, experience on similar projects in Ontarioindicates that the following should be considered:



• Emergency services representatives can be avaluable resource in identifying potential safetydeficient locations and providing input onprojected future conditions; and

• Planned regional attractions and growthconsiderations outside of the subject jurisdictionshould be incorporated into the forecastingexercise.

It should also be recognized that traffic growth issubject to the impact of regional economic activitiesand development and can fluctuate as regionaleconomic activity varies. As an example, historicalAADT data for Highway 401 at Keele Street inToronto, illustrated in Figure 1, shows how trafficgrowth has varied over the past 45 years withdistinct low growth periods 1981-1983 and 1990-1992. These periods coincide with periods of sloweconomic activity in Ontario.

3.3 Identification of Needs andProblems, Existing and Future

Sections 3.1 and 3.2 identified the processes usedto identify current and future roadway geometry,operating conditions (including volumes andcongestion) and incident profiles. It is necessary toreview this information to determine if there areconcerns with the current and future operations ofthe roadway that need to be rectified.

The following sections identify a number ofcategories for system measures of effectiveness.

3.3.1 Geometric Constraints

On a section-by-section basis, the subject roadwaymay be evaluated for a number of Measures ofEffectiveness (MOEs) related to roadway geometry.For example, lack of shoulders impacts the ability ofthe network to handle incidents, as any incident(regardless of the duration) will result in a laneclosure, limiting roadway capacity for passing trafficand reducing the accessibility of the incident sceneto emergency response vehicles.

Figure 1 – Historical Traffic Growth on Highway 401 at Keele Street

1965 19691967 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

100120140160180200

220240260280300320340360380400

4 Lanes 12 to 16 Lanes

Beginning ofIncident Management

Implementationof COMPASS

Year

Veh

icle

s /

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(th

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The ATMS planning process must take intoconsideration and reflect any plans for futuregeometric improvements. In some cases, geometricimprovements may be difficult to implement, asmany mature roadway sites are constrained by right-of-way limitations, topography, environmentalconsiderations, etc. In these circumstances, ATMSmay be used to mitigate the operational impacts ofthe existing geometric constraints.

3.3.2 Network Operating Conditions

Similarly, on a section-by-section basis, the subjectroadway may be evaluated using the measuresidentified to quantify the existing and futureoperating conditions.

A V/C ratio of approximately 0.85 or higherdescribes a roadway that is nearing, or is atcapacity. At this V/C ratio, vehicles are spaced atapproximately six car lengths, leaving little room forvehicles to manoeuvre. With traffic flow so close tocapacity, the traffic stream has no ability toaccommodate any minor fluctuation in trafficdemand or even the most minor of disruptions. Inthese circumstances, any disruption or minorincrease in traffic can propagate serious capacitybreakdown and extensive queuing, both within thecapacity-deficient section as well as for a significantdistance upstream.

Identification of an acceptable peak-hour speed canbe used as a secondary MOE. A peak hour speed ofapproximately 40% of the posted limit is generallyconsidered the speed at which drivers becomeincreasingly frustrated.

An important consideration is the availability of theadjacent arterial road network to accommodatediverted traffic. If the arterial network hasinsufficient capacity, is discontinuous, or otherwiseunable to accommodate a significant amount of

diverted traffic, the duration and subsequent impactsof major and headline incidents may be exacerbated.These constraints to the transportation system areworth noting.

Where there are multiple candidate routes for ATMSdeployment, either as an initial installation or as asystem expansion, these measures may be used toassist in establishing priorities.

3.3.3 Incidents

As with the network operating conditions, measuresused to quantify existing and future incident profilesmay be used as MOEs. Useful MOEs include:

• Collision frequency (collisions/year or collisions/km/year);

• Collision rate (collisions per million vehicle-kilometres or collisions per million enteringvehicles);

• Collision severity (frequency of collisions byseverity [fatal, injury or property damage only]);and

• Incident duration (number of lane closure hours,incident detection time, emergency responsevehicle response time, incident clearance time,etc.)

While collision-rate data is typically published, it isthe incident rate that impacts traffic. As a result, it isimportant to draw a relationship, or correlation,between incident rates and collision rates, drawingupon the experience of various operating ATMS withsimilar characteristics.



3.3.4 Environmental Concerns

The impacts of congestion on the environmentshould be considered. To the extent that recurringand non-recurring congestion can be mitigated, fuelconsumption and vehicle emissions are minimized.In the U.S., many corridor congestion managementprograms have applied Federal EnvironmentalProtection Agency funding.

3.3.5 Stakeholder Input

Consultation with stakeholders, including public,commercial vehicle operators, road maintenanceauthorities, other provincial or municipal trafficauthorities, police and emergency services, transitoperators, etc., can reveal additional existing oranticipated problems related to the performance ofthe transportation system.

3.3.6 Other Factors

It may be appropriate to incorporate othergovernment systems or objectives. For example, theeffectiveness of local emergency response plans,and the coordination of the road system with air andwater transportation systems, could be evaluated todetermine if there are any shortcomings that mightbenefit from ATMS deployment.

3.3.7 Development of ConsolidatedProblem and Needs Statement

From the above-noted review of available traffic dataand stakeholder consultations, the range oftransportation system concerns has been identified.This information is most effective when consolidatedand expressed in a concise format using quantifiableterms to produce an overall Needs Statement. In thisway, it will be possible to determine if theseproblems can be alleviated with the introduction ofthe management, institutional and operationalimprovements typically associated with ATMS.


The Ministry of Transportation Ontario’s Ontario ITSStrategies Framework Study and Five YearCOMPASS Implementation Plan incorporates aneeds analysis of the provincial freeway network inorder to prioritize areas of deployment for theCOMPASS ATMS Program. Each freeway link hasbeen characterized in terms of geometrics, trafficoperations and incidents based upon available data.Other considerations which were incorporated intothe analysis included coordination with plannedroadwork activities and proximity to existing ATMSinstallations.

Lessons learned in conducting the needs analysis forthe COMPASS Implementation Plan indicated thatthe process benefits from:

• Learning from the experience of other jurisdictions;

• Including regional planning agencies in theidentification of needs; and

• Involving police and emergency service agenciesas early as possible.

3.4 Establishment of ATMSGoals and Objectives

Operating goals and objectives will arise out of theneeds identified in the previous section. These goalswill likely be aimed at providing transportationproducts and services that can have a positivesocietal impact by improving safety, supporting ahigher quality of life, and increasing theattractiveness of a community for business. To thisend, the following goals and objectives for ATMSdeployment focus on increasing the level ofperformance of existing transportation products andservices to meet the social and economic needs ofthe people of Ontario.



3.4.1 Increase Capacity andOperational Efficiency

By providing early detection and response toincidents and congestion, ATMS optimizes the useof the existing network capacity and reduces theneed for building additional infrastructure. It alsoimproves the ability to better manage traffic flows,reduce congestion and delay, and encourage a morebalanced use of all modes of travel.

3.4.2 Increase Productivity forCommercial Vehicles

Increased operational efficiency results in improvedand more consistent travel times for all users of theroad network. For commercial carriers, this translatesinto reduced costs and improved productivity, andcontributes to the overall industrial competitivenessof the region.

3.4.3 Improve Safety

ATMS applications provide the opportunity to reducethe occurrence of primary and secondary collisionsby:

• Controlling conflicting traffic movements atintersections, freeway entrance ramps, etc.;

• Advising and controlling traffic movements on theapproach to and through atypical conditions, suchas incidents, work zones, inclement weather, andcongestion; and

• Minimizing the duration of recurring and non-recurring congestion.

3.4.4 Increase Traveller Comfortand Convenience

ATMS applications provide the opportunity todisseminate information on current travel conditionson a region-wide scale. This helps travellers makeinformed decisions with respect to temporal, spatial,and modal shifts in trip patterns. As a result, theoverall accessibility and convenience of the transportnetwork is improved, with reduction in driverfrustration.

3.4.5 Improve Public TransportationServices and Operations

Current traffic conditions information can becombined with transit service information to helpfacilitate appropriate pre-trip travel decisions. Thiscan result in a shift of commuter travel patterns topublic transportation where viable transit optionsexist.

3.4.6 Improve Cooperation AmongstTransportation Operators

The benefits associated with ATMS increasesignificantly as a region-wide level of deployment isachieved. Opportunities for cooperation in thedelivery of regional ATMS services includes sharedcollection and use of data, multiple uses for fieldcomponents, coordination of network operations,shared use of maintenance resources, andcoordination of information services, all of which canimprove system efficiencies and lower costs. Thesecooperative relationships should be pursued betweengovernment agencies, and with the private sector, todeliver ATMS services as effectively and efficientlyas possible.



3.4.7 Reduce Environmentaland Energy Impacts

ATMS systems smooth traffic flow, producing higheraverage network speeds and fewer stops. Thisprovides a near-term benefit in terms of reduced fuelusage and emissions. Over the longer term, it isimportant that ATMS systems be considered as anintegral component of a broader array of ITSelements and the transport planning process as awhole, in order to optimize the overall efficiency ofthe transport network. This holistic approachincorporates demand-management measures, andimproves the attractiveness of transit options.

3.4.8 National Context

The ATMS goals stated above complement andsupport the goals outlined in Transport Canada’s AnITS Plan for Canada: En Route to Intelligent Mobility.These include efforts to:

• Improve the safety of Canada’s groundtransportation system;

• Increase operational efficiency and capacity of theground transportation system;

• Reduce energy and environmental costsassociated with ground transportation;

• Enhance productivity and competitiveness;

• Improve the collection of information and data forpolicy making, planning, program managementand evaluation, traffic operations, enforcement,and congestion monitoring;

• Enhance personal mobility, convenience andsecurity of the ground transportation system;

• Create opportunities for Canadian companies inthe global marketplace; and

• In general, create an environment in which thedevelopment and deployment of ITS will flourish inCanada.

Similarly, the U.S. Department of Transportation’sNational ITS Architecture provides the followinggoals:

• Increase capacity and operational efficiency;

• Enhance personal mobility;

• Reduce energy and environmental cost associatedwith traffic congestion;

• Improve safety;

• Enhance present and future productivity ofindividuals, organizations and the economy as awhole; and

• Create an environment in which the developmentand deployment of ITS can flourish.

The Ministry of Transportation Ontario’s ITSStrategies – Moving Forward with Intelligencebased its goals and objectives on those of TransportCanada’s ITS Plan for Canada as well as the thosearticulated in the ITS Architecture for Canada.

3.4.9 Performance Monitoring

Performance monitoring of an ATMS helps toidentify how well the system meets its goals andobjectives and quantify the associated benefits. It isa key aspect of any deployment project and onewhich should be considered throughout the planningand design phases to ensure it can be undertakeneasily and that both the ‘before’ and ‘after’conditions are well documented. The guidelinespresented in Transport Canada’s Final Report on the“Development of a Project Evaluation MethodologyFramework for Canadian Intelligent Transportation



Systems” presents typical measures for performancemonitoring that are in keeping with the goals andobjectives for ATMS deployment. These measuresare summarized below:

• Safety– reduction on overall crash rate– reduction in fatal crashes– reduction in injury crashes– reduction in secondary crashes

• Mobility– reduction in travel time delay– reduction in travel time variability

• Efficiency and Productivity– increase in roadway throughput– cost savings for users– cost savings for agencies (emergency response,

road maintenance, etc.)

• Energy and the Environment– decrease in vehicle emissions– decrease in vehicle energy consumption

• Security– reduction in acts of crime against motorists and

property– reduction in response time to incidents (rural

applications)

• Customer Satisfaction– increase in customer satisfaction.


The experience of Ontario transportation agencies inthe planning and definition of ATMS applicationssuggests that it is important to:

• Keep the goals well-defined and realistic;

• Carefully estimate the lead time required toaccomplish the established goals;

• Include all stakeholders in the goal definitionprocess;

• Provide for education of the travelling public; and

• Provide performance monitoring to track progressagainst the defined goals.

3.5 Review of NetworkRequirements and Plans

In planning ATMS deployment, a number ofconsiderations outside of the subject roadway needto be considered. These include the availability andjurisdiction of diversion routes, inter-agency andinter-jurisdictional coordination of constructionprojects, and network management responsibilities.

3.5.1 Coordination of DiversionRoute Management

ATMS deployment may impact traffic flow andrequire use of diversion routes to manage trafficduring construction. ATMS operation may alsoimpact parallel routes as traffic management plansare put into effect that divert traffic to alternateroutes in order to manage an incident or recurrentcongestion. A collaborative effort is required withjurisdictions that are responsible for these diversionroutes.

During ATMS deployment, this could include areview of any planned infrastructure improvementsand schedules along diversion routes, and thecoordination of ATMS construction activities withthese infrastructure improvements. Temporary ATMSfacilities can also be used to mitigate the impact ofATMS deployment. Information on constructionactivities (regardless of the responsible jurisdiction)can be disseminated to the motorist. For example, aPortable Variable Message Sign (PVMS) can beimplemented upstream of a construction zone to



warn motorists of lane restrictions ahead. This willimprove work zone safety for both the workers andthe motorists, as well as help to improve publicrelations with the travelling public.

Recommended diversion routes may include ATMS-monitored signalized arterial roadways. In thissituation, coordination with the jurisdictionresponsible for ATMS operation on these routes canbe of benefit to the motorist. For example, during amajor or headline incident, an upstream DynamicMessage Sign (DMS) may be used to warnmotorists of the situation ahead. When ATMSoperators inform the jurisdiction responsible for thearterial (diversion) traffic signals of the collision, theycan implement timing strategies that will favour thearterial roadway to better manage the divertedtraffic. Furthermore, the signal system jurisdictioncould proactively develop signal timing plans torespond to a severe incident, or implement a trafficresponsive/adaptive signal system that wouldautomate this process.

Further coordination between jurisdictions mayprovide route management capabilities where thediversion routes are monitored by an ATMS. In routemanagement, an alternate route is suggested basedon calculated travel time estimates. Routemanagement allows for a more balanced use of theavailable capacity on the two roadway sections.Information on route options can then bedisseminated to the motorist. ATMS diversion routingschemes can be supported through the applicationof static trailblazer signage along the diversionroutes.

Use of a simulation tool for the modelling of theroadway network, in an off-line mode or in real-timewhen available, can assist in scenario analysis andselection of the most effective response plan (i.e.,diversion route) for implementation duringconstruction activities or in response to incidents.


Through the period 1993 to 2000, the City ofToronto undertook a major reconstruction effort forthe Gardiner Expressway and Lake Shore BoulevardHumber Bridges project on the Toronto waterfront.The project called for the successive demolition andreconstruction of six bridges in this major corridorwhich provides direct access to central Toronto fromthe west. In planning for the project, the City andthe MTO worked together to establish an area-widetraffic plan which considered the impacts on thearea’s arterial network with use of off-line simulationtools to optimize the traffic response plans, andestablish diversion routing between Lake ShoreBoulevard and a parallel arterial, The Queensway.The result of the process was an ATMS deployment,which included traffic monitoring and advisoryinformation to motorists as they approached routingdecision points in the vicinity of the work zone.

The experience of various transport authoritiesemphasizes the need to have all stakeholders worktogether at each phase of the project to identify andmanage diversion routing. Stakeholders include thevarious road authorities as well as transit agencies,emergency services, etc. Halton Region andWaterloo Region have recently embraced thisapproach in undertaking the development of region-wide emergency plans to provide a structuredprocess in coordinating responses to naturaldisasters, evacuation scenarios, etc.

3.6 Selection ofAppropriate Strategies

The traffic monitoring and detection function is oneof the key building blocks upon which any ATMS isfounded. It is imperative to obtain reliable and up-to-date information on prevailing conditions on the roadnetwork in order to competently influence futuretraffic behaviour and provide traveller informationthrough traffic management strategies. Variousautomated and manual techniques are available to



assist in traffic monitoring and incident detection/confirmation activities, including vehicle detectionsystems and closed circuit television (CCTV)systems.

Various ATMS strategies are available to support theoperator goals and objectives identified in Section3.4. They can be broadly categorized into Incident,Congestion, Corridor, Network and Travel DemandManagement strategies. Table 1 illustrates theapplication of these strategies.

The following sections provide an “ATMS toolbox” ofoptions to suit a range of operator needs.

3.6.1 Incident Management

Incident Management strategies focus onmaximizing the use of available roadway capacityand reducing the impact of non-recurring congestionresulting from incidents. They are designed toreduce the overall duration of an incident, therebyreducing the safety and capacity impacts of eachstage of an incident as follows:

• Incident-to-detection time is minimized through theapplication of automatic incident detection,motorist call-in services, agency coordination (911calls), and CCTV confirmation;

• Detection-to-response time is minimized throughCCTV assessment of the incident, automatedresponse plan generation, and optimized responseagency communication;

• Response-to-clearance time is minimized throughpre-determined response agency coordination; and

• Time to return to normal operating conditions isminimized through application of variouscongestion management and traveller informationstrategies.

Reducing the duration of these stages improvessafety by reducing secondary incidents, results insavings in vehicle operating costs, and reduces theamount of harmful emissions.

Table 1 – ATMS Strategies

Strategy Description Requirements

Incident ManagementEarly detection and response tounscheduled events

• Incident detection/confirmation• Emergency response/motorist assistance• Pre-trip and en-route advisory

Congestion Management

Mitigating the impacts of recurringand non-recurring congestion

• Congestion monitoring• Pre-trip and en-route advisory• Lane metering• Ramp metering

Corridor ManagementBalancing level of service amongalternate parallel routes within a corridor

• Event and travel time monitoring• Pre-trip and en-route advisory

Network ManagementBalancing level of service within thenetwork as a function of currentconditions

• Event and travel time monitoring• Pre-trip and en-route advisory

Travel DemandManagement

Improving traffic flow by managing traveldemand

• Congestion pricing• Ramp metering



Incident management strategies can beimplemented on an automated or non-automatedlevel. The automated incident management strategyimplemented by an ATMS consists of three generalsteps:

• Incident detection• Confirmation of the incident• Implementation of response measures.

Following detection of an incident by the system, thesystem prompts the operator to confirm the incident.For incidents that are not detected by the system(e.g., the event is detected by motorist calls to 911,or by staff or police on the road, or by operatorexperience), the operator will enter the event detailsmanually. With the increasing market penetration ofcellular telephones and expanding CCTV deploymentallowing operators to monitor more known troublespots, many ATMS operators are increasingly relyingon these other detection sources.

Upon incident confirmation, the system willautomatically analyze all data gathered by thedetection systems and the incident details providedby the operator, and determine suitable responsesbased on current roadway conditions. Modernincident management systems typically use anautomated “logic-based” approach, or a combinationof “logic-based” and “plan-based” approaches toformulate a suitable response to ensure safe andefficient flow of traffic throughout the network.Using non-automated approaches alone are notrecommended due to the large volume of manualwork required and the high risk of operator error.

The incident management response that the systemimplements is based on the traffic managementstrategies that are in place, and the availability ofappropriate devices to control traffic or displayinformation. The following sections describe devicesand strategies that can be used to respond to anincident.

Traffic Information Dissemination

The provision of incident information and real-timetraffic conditions through a variety of motoristcommunication modes is key to effective incidentmanagement. These communication modes areoutlined in Section 4.5.

Detection and communication of unexpectedadverse weather conditions, such as high winds onskyways, can also significantly improve safety.Advisory information may provide general or vehicle-specific advisories (e.g., wind advisories for largevehicles), and directions to alternate routes or safetemporary vehicle parking or storage facilities.

Surface Street Control System Integration

The ability to monitor on-street conditions in realtime provides certain advantages when employed incombination with a surface street control system.Traffic Operation Centres use CCTV and real-timetraffic data monitoring to allow an operator tomanually adjust traffic signal control parameters toimprove on-street operations. Alternatively, traffic-adaptive and traffic-responsive control systems mayadjust automatically to accommodate the changingon-street conditions resulting from an incident. Forincident management strategies involving diversionroutes, the development and use of pre-plannedincident response timing plans would be beneficialfor coordinated arterial signal control duringincidents.

Other incident response strategies includemanaging traffic flow into the freeway corridor bothupstream and downstream of the incident locationby altering ramp metering rates in an effort to betterbalance available capacity. On-road response mayalso be utilized by dispatching vehicles (e.g., blockertrucks), equipment (e.g., cones, portable variablemessage signs, etc.) and staff to manage traffic atthe incident site and provide protection foremergency response personnel.



3.6.2 Congestion Management

Congestion Management strategies employ avariety of traffic management and control strategiesto mitigate the negative impacts of recurringcongestion. In so doing, these strategies optimizeroad capacity and improve road safety for generaltraffic and vehicles involved in maintenance andconstruction activities.

Traffic Information Dissemination

The provision of real-time and traffic conditionsthrough a variety of communication modes is key tothe effective management of a congested roadnetwork by providing motorists the opportunity tochange their route or the timing of their trip. Thesecommunication modes are outlined in Section 4.5.

Lane Management

Lane management provides lane-specific informationto motorists through the use of overhead-mountedlane control signs (LCS). They are typically used aspart of a congestion management strategy bydisplaying information relating to lane availability.LCS displays include a downward pointing greenarrow indicating that the lane is available, or a red“X” indicating the lane is not available. The “X”symbol is also used (displayed in red or amber)during the lane clearance interval. Lanemanagement can form part of an ATMS withapplications that include reversible lanes on urbanarterials to manage peak direction traffic demand orfor traffic management purposes in tunnels andbridges during incidents or planned lane closures.

When considering a reversible traffic lane as atraffic management strategy, a key considerationshould be the volume of off-peak traffic and theability to accommodate this volume within theremaining lanes available. Any congestion in the off-

peak direction should be considered in conjunctionwith the benefit gained by peak direction traffic toensure that the net benefit to the transportationnetwork is considered.

Ontario ExperienceAn example of an urban application of lanemanagement can be found on Jarvis Street inToronto where the direction of travel in the centrelane alternates on a time of day basis to providecapacity for the peak direction of travel. Lanemanagement is also utilized on the ChamplainBridge across the Ottawa River between the City ofOttawa and Gatineau, Québec where the systemmanages a reversible HOV lane to accommodatepeak direction traffic flows.

High Occupancy Vehicle (HOV) / HighOccupancy Toll (HOT) Lane Management

High Occupancy Vehicle (HOV) lane managementprovides priority treatment for HOVs through theprovision of reserved lanes with higher operatingspeeds and more reliable travel times. This approachdiscourages the use of single occupant vehiclesduring periods of congestion, encourages ride-sharing and off-peak travel and emphasizes the useof available infrastructure to move people rather thanvehicles. Priority treatments for HOVs have proven tobe very effective.

A related strategy – and a relatively recent lanemanagement concept – is that of High OccupancyToll (HOT) lanes. HOT lanes combine HOV andpricing strategies by allowing vehicles that do notmeet passenger occupancy requirements to gainaccess to HOV lanes by paying a toll. It is a form ofcongestion pricing (also known as value pricing)where the transportation agency sells to motorists,on a time-of-day or congestion-level basis, the excesscapacity available from the operation of HOV lanes.Information on price levels and travel conditions isnormally communicated to motorists via dynamicmessage signs, providing potential users with the



information they need in order to decide whether ornot to utilize the HOT lane. HOT lanes may becreated through new capacity construction orconversion of existing lanes. Conversion of existingHOV lanes to HOT operation is the most commonapproach.

Ontario ExperienceHOV lanes have been operating in Toronto onHighway 403, in both directions between 407 ETRand Highway 401 and more recently have beenimplemented on Highway 404 between Highway 7and Highway 401. The HOV lanes, marked byspecial signs with diamond symbols painted on thepavement, allow buses and vehicles carrying at leasttwo people to bypass congestion in the generalpurpose lanes.

Ramp Metering

Ramp metering uses a traffic control signal onfreeway entrance ramps to control the rate at whichvehicles can enter a freeway facility. In this way, theflow can be moderated to more closely match theavailable capacity of the freeway and to improvemerging by breaking up vehicle platoons into groupsof one or two vehicles. Candidate locations for rampmetering include high volume entrance ramps wherethere is adequate space to store vehicle queueswaiting to access the freeway, as well as sufficientramp length to allow vehicles to accelerate from astop condition to freeway speeds. Consequently, thebenefits of ramp metering include improved freewayoperations (reduced delay, reduced stops, etc.) and ageneral improvement in safety due to a reduction inmerge-related collisions.

The drawback of ramp metering includes therelatively high cost to install and operate such asystem, and the potential for negative publicreaction. Ramp metering is a traffic managementstrategy that is typically regarded by the public as a

method for optimizing flows on the freeway, to thedetriment of the operating conditions on theadjacent arterial routes. Ramp metering is alsoperceived to favour longer trips rather than shorttrips, thereby encouraging more dispersed landdevelopment and more travel. However, if rampmetering is implemented properly, and particularly ifit can be integrated with the local traffic signalcontrol system, the efficiency of the entiretransportation network can be improved. Thesuccess and benefits associated with ramp meteringis demonstrated by the large number of rampmetering stations (estimated to be 2,370 in NorthAmerica in 20053) that have been implemented andare successfully operating throughout NorthAmerica.

Ontario ExperienceThe MTO currently uses ramp metering on theQueen Elizabeth Way through Mississauga.

3.6.3 Corridor Management andNetwork Management

Corridor Management involves the application ofseveral traffic management strategies within aspecific corridor to ensure that available capacity iswell utilized and the overall corridor operatesefficiently. The strategies that are deployed willdepend on the operational objectives for the corridor,the prevailing operating conditions and the physicallayout. Typically this involves the monitoring ofseveral parallel routes and the implementation oftraffic management strategies that maximize theefficiency of each route as well as the overallcorridor.

Network Management is similar to corridormanagement, applying traffic managementstrategies to various corridors with a view tooptimizing the operation of the overall network. Itcan be implemented on a stand-alone basis where

3 Ramp Management and Control Handbook.



each corridor functions independently and theoperator manually selects traffic managementstrategies to manage the road network. Alternatively,it can be implemented on an integrated basis wherethe corridors interact with the rest of thetransportation network. The second option ispreferred as it addresses specific unique corridorfunctions, yet integrates the system so that thetransportation network functions more efficiently.

In addition to the measures used for congestion andincident management, strategies for corridor andnetwork management employ the followingmeasures.

Diversion Strategies

Diversion strategies are implemented when anincident blocks one or more lanes. The goal of adiversion strategy is to move vehicles around theincident as efficiently as possible. There are severaltypes of diversion strategies – local, strategic andtactical. Depending on the location and severity ofthe incident and the systems and devices available,one or more of the diversion strategies can beimplemented.

Diversion of traffic to alternate routes should not beactively promoted unless current traffic conditiondata is available for the alternate route andpreferably, traffic control systems are available torespond to the increase in traffic flow. The ATMSgathers detailed travel data from each route andruns an algorithm to determine which route is thefastest at that point in time. This information canthen be disseminated to motorists through a varietyof methods, such as Dynamic Message Signs(DMS) and other traveller information devices. It iscrucial that information provided to motorists isaccurate and reliable. In order for route balancingstrategies to be effective, traffic monitoring facilitiesmust be available on both routes. Care must beexercised to ensure that the implementation of thestrategy does not result in an oscillation of the travel

time imbalance between alternate routes. Thepercentage of motorists willing to alter trip patternswill vary according to the nature of the roadnetwork, the level of travel time imbalance, and thenature and location of information provided to themotorist.

Local DiversionsLocal diversion strategies for incidents involve smalldeviations from the motorist’s original route to avoidthe incident site. Local diversions may use anyroadway type (i.e., freeway, arterial, collector, etc.),but typically avoid minor residential streets. However,given the unpredictable nature of arterial incidents, itmay be necessary to include residential streets inthe temporary incident diversion route. In the case ofarterial routes, local diversions may be as long asseveral city blocks. For freeways, local diversionsmay be from interchange to interchange and canrange from the simple closure of the affected lanesto diversion of freeway traffic to adjacent arterials tobypass the incident site. A passive approach to localdiversion can be achieved by providing advanceincident information for the primary route, enablingmotorists to make informed routing decisions basedupon individual trip patterns and knowledge of thelocal road network. If active diversion strategies areto be employed, it is important to involve the variousaffected local agencies in an advance planningprocess to identify candidate diversion routes.

Strategic DiversionsStrategic diversions involve a shifting of routing on aregion-wide scale. These diversion strategies areused in the event of major incidents or a full closure.In such cases, it is desirable to advise and re-routetraffic several kilometres upstream from the actualincident site. This higher level of advance warningallows motorists to select alternate routes from anumber of options, thereby spreading the divertedtraffic over as many corridors as possible. It alsoprovides the opportunity for motorists to divert toother freeway corridors which are better equipped to



handle high volume traffic flows. Strategic diversionstrategies could also encourage diversion to othermodes of travel, or possibly avoiding trips all togetheras a result of current conditions.

Tactical DiversionsTactical diversions fall in between local and strategicdiversion strategies. They are used where parallelarterial routes have been identified, and theappropriate traffic control mechanisms are in place(e.g., ATMS in combination with a responsive oradaptive signal control system). A tactical diversionresponse strategy would provide data to theresponsive/adaptive signal system to initiate aspecial signal timing strategy on the parallel arterialto accommodate traffic leaving a freeway. Tacticaldiversion strategies could also encourage diversionto other modes of travel or possibly avoiding trips alltogether as a result of current conditions.

Ontario ExperienceThrough the operation of the COMPASS ATMS onHighway 401 in Toronto, the MTO observed thatmotorists often use Highways 409 and 427 in thevicinity of Pearson Airport to by-pass Highway 401in this area. The Highway 409/427 “airport triangle”serves as an alternate route to avoid Highway 401congestion resulting from a discontinuity in theexpress/collector configuration. Recognizing thenetwork management potential, the MTO hasrecently implemented traffic monitoring on thealternate route and overhead DMSs on both thewestbound and eastbound approaches to thediversion decision points.

Parking Guidance

Traffic circulating in search of available parking cancontribute to network congestion within busy retailor entertainment areas, etc. The provision of real-time parking information through static signs, DMSsor Highway Advisory Radio (HAR) can significantlyreduce on-street traffic volumes in high parking-

demand areas. This strategy is of particular benefitin areas that experience high tourist activity, wherethe visitors are less familiar with the local parkingfacilities.

Scheduled Event Management

Scheduled events present an opportunity to developadequate traffic management strategies thatcoordinate the efforts of traffic control systems,police, traveller information, etc. ATMS may be usedto monitor and react to the event as it proceeds. Forevents that are scheduled and recurring, monitoringand post-event reviews allow for the refinement ofthe event management strategies.

Surface Street Control System Integration

The ability to monitor on-street conditions in realtime provides certain advantages when employed incombination with a surface street control system.Pre-determined traffic control system plans can altertraffic signal splits, cycles and offsets to suit thegoals of the network management plans. TrafficOperation Centres can monitor the progress of thenetwork management plan and implementalterations to the plan to benefit on-street conditions.

3.6.4 Travel Demand Management

The objective of Travel Demand Management (TDM)is to improve traffic flow by managing traveldemand. In general, it is achieved through one ofthe following initiatives.

Electronic Road Pricing

Electronic Road Pricing facilitates demandmanagement and operations to mitigate the impactof traffic congestion. It features additional usercharges and differentials based on time, place,distance of travel, and vehicle type to effectchanges in travel behaviour.



A few cities around the world have implementedvarious forms of congestion pricing, includingSingapore, Orange County (California State Route91), City of London in the U.K., Cities of Trondheim,Oslo and Bergen in Norway, and the 407 ETR inOntario. For the Congestion Pricing Systemimplemented in London, U.K. since February 2003,motorists driving in central London on weekdaysbetween 7:00 am and 6:30 pm are required to pay£5, increasing to £8 in July 2005. The congestionpricing system uses a network of video cameras torecord license plate numbers, and optical characterrecognition (OCR) technology to read thisinformation, identify “unpaid” vehicles, and generatecitations for violators.

Ontario ExperienceIn Ontario the 407ETR, a multi-lane, electronic tollhighway which serves the Greater Toronto Area,varies toll charges by time of day and day of week.Higher toll charges are utilized during the peaktraffic periods.

Ride-Matching and Carpooling

Ride-matching/carpooling makes ridesharing easierand more convenient for travellers, and encouragesthe use of high occupancy vehicles during periods ofcongestion. Carpooling involves two or more peoplesharing a ride to a mutual, nearby or consecutivedestination to save gasoline, driving and theenvironment. Incentives to promote carpoolinginvolve priority parking privileges (costs and spaces),guarantee of an emergency ride home and the useof special lanes. Some HOV facilities in operation inNorth America are connected either directly orindirectly to park-and-ride lots to promote the use ofboth ride-sharing and HOV facilities.

Ontario ExperienceIn Ontario, the Share-a-Ride program has expandedfrom a government employee-only program to aprovince-wide computer ride-matching system. The

Smart Commute Initiative (www.smartcommute.ca),a partnership of Greater Toronto Area municipalitiesand the City of Hamilton, with financial support fromTransport Canada and the private sector, waslaunched in June 2005 to offer commuters choicesfor getting to work or school and to provide directservices for employers and their employees. TheGovernment of Canada has also launched the newride-matching system (www.Ottawaridematch.com)in May 2006 for federal employees working inOttawa, Ontario, and Gatineau, Québec, to findpotential carpooling matches based on proximity tohome and work, and similar working hours.

Pre-Trip Travel Information

Pre-trip travel information provides information totravellers in order to select the best transportationmode, departure time and route prior to their trip,and helps to reduce single-occupancy vehicledemand by assisting travellers in finding ridesharingopportunities. This can be done through a telephonecall-in number, a cable TV traffic station, orinformation from the internet. MTO maintains awebsite (www.mto.gov.on.ca/compass.htm) toprovide real-time traffic information for the GreaterToronto Area (GTA) and the Niagara Peninsularegions. The City of Toronto maintains a similarwebsite (www.toronto.ca/rescu/) for real-time trafficinformation on major Toronto roadways.

3.6.5 Summary

The following items should be considered whenidentifying relevant ATMS strategies:

• Involve experts in the ITS field to assist withstrategy development;

• Incorporate stakeholder input when identifyingrelevant strategies;



• Discuss strategies with local transportationagencies, including operators of existing ATMSsystems;

• Focus on strategies and products that are provenand readily available;

• Incorporate maintenance and life-cycle costs intodecisions regarding ATMS strategies;

• Consider methods of phasing in strategies (one ata time) so that impacts can be discretelyobserved; and

• Ensure that strategies are well understood by themotoring public before they are implemented.Strategies that are outside of the local trafficoperations experience may result in motoristconfusion or misunderstanding.

3.7 Identification of ATMSSubsystems and Components

3.7.1 Mapping Subsystems to Strategies

ATMS applications incorporate various subsystems,which facilitate the traffic management strategiesas illustrated in Table 2.

3.7.2 Subsystem Descriptions

Monitoring

The Vehicle Detection Subsystem (VDS) provides forthe collection of current traffic data. A series ofsensors measure vehicle presence and is interfacedto a roadside field controller which computes trafficvolume, occupancy and speed data. Data is typicallyaggregated into 20 or 30 second summaries fortransmission to a central computer.

Note: X – Primary RoleO – Secondary Role

Table 2 – Mapping of Subsystems to Strategies

Subsystem Incident Management CongestionManagement

Corridor & NetworkManagement

Monitoring

Vehicle Detection X X X

CCTV X X O

Advisory

Dynamic Message Signs X X X

Arterial Advisory Signs O O X

Queue Warning Signs X X

Traveller Information O X X

Traffic Control

Traffic Signals O X X

Ramp Metering O X O

Lane Management X



The CCTV camera subsystem (pan/tilt/zoom videocamera) is a monitoring tool used by operators tomonitor traffic flow and confirm incidents andcongestion events. CCTV cameras are a valuabletool to the operator capable of providing a variety ofinformation related to the event. Cameras aretypically mounted on roadside poles or high-levelrooftop locations adjacent to the corridor.

Advisory

Various approaches are used to provide scheduledand unscheduled event information to motorists:

• Dynamic Message Signs (DMSs) are typicallycomprised of an overhead or roadside-mountedpixel display capable of rendering any number ofmessages, and are located within the corridor inadvance of key motorist decision points, such asfreeway to freeway interchanges.

• Arterial Advisory Signs are smaller-scale DMSslocated on crossing arterial roads in advance offreeway entrance ramps.

• Queue Warning Signs are smaller-scale DMSslocated along the corridor, spaced at regularintervals to provide advance warning ofcongestion and improve safety.

• Traveller Information Systems employ a variety ofinformation media to provide current trafficcondition information to motorists – pre-trip or en-route. Systems might include commercialbroadcast media, Highway Advisory Radio (HAR),interactive voice response, pager service, internetsites, fax service, etc.

Traffic Control

The traffic signal subsystem employs traffic signalsto control conflicting vehicle and pedestrianmovements at arterial intersections. Traffic signalsmay operate on an isolated basis (independent of

the operation at adjacent signalized intersections) orin a coordinated mode, typically done under thesupervision of a central control and monitoringsystem.

The ramp metering subsystem employs trafficsignals to meter the flow of traffic entering thefreeway, thereby improving merge conditions on thefreeway.

The lane management subsystem provides lane-specific information to motorists indicating laneavailability. It is typically used for alternating orreversing lane direction to improve capacity of urbanarterials in order to meet peak direction trafficdemand, or in tunnels or bridges to assist in trafficcontrol during incidents or planned lane closures.

3.8 Project Implementation

To define the project scope, the ATMS goals andobjectives established in Section 3.4 are applied tothe needs and problems identified in Section 3.3.The geographic scope of the ATMS deployment willbegin to materialize as each goal is overlaid on aproblem area. Based on this analysis, it may beapparent that significant incremental benefits can berealized if modest extensions to the ATMSgeographic scope are implemented.

An initial schedule for ATMS implementation shouldbe developed, using the geographic scope to gaugetiming needs and phasing. The schedule shouldreflect construction coordination issues with otherjurisdictions identified in Section 3.5. Also, the rolesand responsibilities of other jurisdictions duringATMS implementation and operation can beidentified once the geographic scope of the ATMSproject is determined.

A preliminary budget should be developed thatprioritizes funding based on the key problem areasand needs, and their corresponding goals andobjectives.



Savings in construction costs can be realized bystaging ATMS equipment installation with plannedinfrastructure improvements. Whenever possible,provisions for ATMS infrastructure can be included inthese construction projects (e.g., spare duct forATMS communications purposes). Coordination ofconstruction activities also helps to reduce disruptionto the motorist.

Ontario Experience• City of Toronto Road Emergency Services

Communications Unit (RESCU) – A detailed five-year implementation plan was developed at theoutset of the City of Toronto RESCU systemdevelopment (formerly Gardiner-Lake ShoreCorridor Traffic Management System). The projectlife cycle was defined in terms of functional andgeographic areas of activity, and staged over afive-year timeframe in consideration of annualcapital funding availability. Key areas of activityincluded:

– system definition– detailed design and specification– software development– civil/electrical provisions installation– field subsystem installation– testing and integration– operations and maintenance support.

• Ontario ITS Strategies Framework Study andFive-Year COMPASS Implementation Plan – TheMinistry of Transportation Ontario’s five-yearimplementation plan established animplementation plan for COMPASS expansionprojects. The plan was developed based onpriorities established as a result of the evaluationof candidate projects, including benefit/costanalysis and scheduled to meet fiscal constraints.The implementation plan also considered otherprojects committed to by the MTO or otheragencies (such as the MTO’s Corridor InvestmentPlan and increasing priority for national security),as well as unique situations to provide a logical

phasing of projects. It is noted that there is not asingle solution to any implementation plan.Different phasing and scheduling needs to beconsidered to meet changing needs and priorities.

• Ontario experience in managing major multi-yearATMS deployment programs suggests that it isimportant to:

– undertake a benefit-cost assessment torationalize investment;

– employ value engineering techniques in thesystem definition and design processes;

– develop a phased implementation, makingoptimal use of funding and staffing levels;

– ensure that the ATMS system proposedaddresses specific needs;

– define a reasonable, not optimistic, timeframefor deployment; and

– use peer review groups to analyze thecomponents of the study to ensure a reasonableapproach and scope are adopted.

3.9 Determination ofRecommended Solutions

The following is a summary of the pre-constructionATMS development process as presented in thepreceding sections:

• Define the project environment in terms ofcurrent and future physical environment, trafficdemand, etc.;

• Define user needs and develop project goalswith stakeholders;

• Identify specific system strategies to facilitatethe goals;

• Identify the specific required subsystems and thecurrent state of the enabling technologies;

• Develop system performance requirements;• Prepare a system preliminary design; and• Develop an implementation plan for the

functional and geographic deployment of thesystem.



4. ATMS DesignConsiderations

An Advanced Traffic Management System (ATMS)refers to the application of current and innovativetraffic operation technologies to monitor and controlvehicles in response to a dynamic traffic condition.ATMS integrates new and existing trafficmanagement and control systems servicing allmodes of transportation. The major components ofATMS are identified as follows:

• Information Collection (real-time data)• Surface Street Control• Highway Control• Regional Traffic Control• Traffic Information Dissemination• Computer System• Communications System.

The available technologies for ATMS applications areevolving rapidly. Many of these technologies benefitfrom research and product development for broaderindustry applications beyond transportation, such ascommunications, entertainment, and security. It isimportant that the ATMS authority undertakes astructured approach to technology review at thepreliminary design stage of any major newdeployment initiative. The technology review processtypically incorporates the following activities foreach candidate ATMS subsystem:

• Identification of user needs;

• Identification of system performance requirements;

• Identification of evaluation criteria includingfunctional performance, physical requirements,electrical requirements, environmental parameters,maintenance requirements, failure rates,adherence to standards, availability, and cost;

• Investigation of industry best practices throughconsultation with other ATMS operators andadvisors;

• Investigation of current available products;

• Investigation of ongoing research anddevelopment efforts to identify emergingtechnologies;

• Short-listing of candidate technologies/products;

• Detailed analysis against evaluation criteria; and

• Recommendations of technologies/products to beincorporated in the detail design process.

In some cases, the technology review process willresult in an in-situ comparison test of candidateproducts supplied on loan from product distributorsand/or suppliers.

The discussion on technologies in the followingsections has been based on technologies that arecurrent and proven at the time of publication and notemerging technologies, unless indicated otherwise.It is important for the practitioner to evaluate thelatest technological advancements and consideradopting the state-of-the-art and/or state-of-the-practice in technologies at the time of their ATMSdeployment.

4.1 Information Collection(Real-time Data)

To implement ATMS, real-time traffic monitoring andinformation collection capabilities must be provided.Advanced technologies for vehicle detectors, closed-circuit televisions, call boxes, vehicle probes,weather data systems, etc., have rapidly emerged inthe last few years, making comprehensive and



sophisticated traffic monitoring and informationcollection capabilities readily available. This sectiondiscusses the application of systems related to real-time information collection functions.

4.1.1 Vehicle Detection System

Concepts

A vital element of ATMS is the vehicle detectionsystem, which is used to provide a means for atraffic operator to monitor traffic conditions, detectincidents, and implement control procedures. Theprimary role of the vehicle detection system is tocollect accurate traffic flow data (volume,occupancy and speed), on a real-time basis, that canbe used to determine traffic flow characteristics formonitoring and statistical purposes.

A vehicle detection system is typically comprised ofthe following functional elements:

• Sensors – measure traffic parameters and areinstalled in the pavement in the case of magneticdetectors and inductive loops; or above pavementin the case of ultrasonic, video imaging,microwave and infrared detectors.

Figure 2 – Typical Cabinet Arrangement(a)

(b)

(c)



• Electronics Unit – housed in the controller cabinetto support functions such as selection of loopsensitivity and pulse or presence mode operation.In some cases, such as microwave, the sensorsand the electronics unit may co-exist. In othercases, such as loops, they may be separate piecesof equipment, with the electronics unit containingan oscillator and amplifiers that excite theembedded wire loop. As a vehicle passes over theloop or is stopped within the area enclosed by theloop, the change in inductance is sensed by theelectronics unit, and interpreted as a detectedvehicle by the controller.

• Field Controller – used to process, summarize,store and transmit detector data. Depending onthe controller, the detector data is eithertransmitted to a central site in raw form orsummarized locally prior to transmission. Somedetectors include these functions with the sensor.

Functions

One of the key functions for the vehicle detectionsystem is to provide traffic data to a TrafficOperation Centre.

The function of the vehicle detection system is tomonitor traffic flow characteristics in terms of thefollowing traffic parameters:

• Vehicle Count (lane/location)• Vehicle Speed (lane/location)• Occupancy (lane/location)• Vehicle Classification (by different length group)• Headway (lane/location)• Flow Rate (selection, hour and day).

Typically, vehicle count and occupancymeasurements are directly obtained from thedetector. In some cases, speed can also be directlymeasured. The remaining parameters can be derivedor extrapolated based upon the available raw data.

The vehicle detection system is also employed toprovide real-time display of traffic statistics. Typically,vehicle counts, speed and occupancy are showngraphically to reflect real-time traffic conditions. Thevehicle count information is also useful for trafficengineers for historical traffic analysis andforecasting.

4.1.2 Detector Technologies

Vehicle detectors form an integral portion ofpractically every modern traffic control andmanagement system. There is a wide range ofavailable vehicle detection technologies, eachcustom tailored to the ATMS applicationenvironment. It is difficult to identify a single leadingdetection technology, as the appropriate selectionvaries according to a number of parameters. Mostsignificantly, the ATMS authority must consider:

• What is the relative priority of the traffic dataparameters required for the ATMS application?Some applications, such as traffic signalactuation, must have very robust presencedetection capabilities. Others, such as travel timemonitoring, emphasize speed data collectioncapabilities.

• What are the limitations of the physicalenvironment? In-pavement technologies, such asthe inductive loop detector, may not be viable ifroad resurfacing is planned. Conversely, overhead-mounted detection may be cost-prohibitive if thereis a lack of existing structures to facilitatemounting.

The vehicle detection market is a varied, competitivemarket characterized by large-scale diversifiedvendors as well as niche suppliers. A significantvolume of comparative technology assessmentdocumentation is available in the ITS industry,although the content of past efforts tends tobecome outdated quite rapidly.



Currently available detection systems can begrouped into the following categories:

• Embedded Detectors• Non-intrusive Detectors• Environmental Sensors• Probe-Based Sensors.

Table 3 provides a summary of the advantages anddisadvantages of the embedded and non-intrusivedetectors that are currently available. Detailedinformation on these detectors can be found in theFreeway Management and Operations Handbooksponsored by the Federal Highway Administrationand the U.S. Department of Transportation.

Detailed descriptions of the three detectortechnologies that have been installed or are beingtested in Ontario, namely the inductive loop detector,video image detection and microwave radardetection are provided below.

Inductive Loop Detection (ILD)

Inductive loops provide the required volume,occupancy and speed data for ATMS applications ina cost-effective manner and are considered to bevery accurate. Some field controllers can alsoestimate vehicle size, gap and headway. Loopsoperate well if installed correctly for the specificdata required and the “amplifier” is set to appropriatesensitivity. Figure 3 illustrates a typical arrangementof a double or speed inductive loop.

The major advantages of an inductive loop detectionsystem include:

• Solidly proven and reliable technology – ILD hasbeen used since the earliest computerized trafficcontrol systems;

• Good passage and presence detection providingaccurate volume, speed and occupancy data; and

• Design of the “amplifier” electronics havesignificantly reduced earlier problems associatedwith loop detectors such as oscillation, cross-talk,variations in activation and deactivation delay, andsensitivity adjustments and range.

While loop technology is proven and effective with arelatively low initial capital cost, if not installedcorrectly loops may require a significant andcontinual maintenance program of replacement.This disadvantage can be significant since loopinstallation works, if not coordinated with otherconstruction work, may result in substantialdisruption to traffic due to lane closures.

The typical failure mode for loops is not the wireembedded in the roadway pavement, but theamplifier contained within the electronics unit, whichcan be repaired by one staff person, without abucket truck, and at a cabinet which is off theroadway in a protected area.

Figure 3 – Typical Inductive Loop Arrangement



Table 3 – Summary of Traffic Detectors

Technology Advantages Disadvantages

Magnetometer(Induction or searchcoil magnetometer)

• Can be used where loops are not feasible (e.g.,bridge decks).

• Some models are installed under roadwaywithout need for pavement cuts. However,boring under roadway is required.

• Insensitive to inclement weather such as snow,rain, and fog.

• Less susceptible than loops to stresses oftraffic and temperature.

• Easy to calibrate.

• Installation requires pavement cut or boringunder roadway.

• Cannot detect stopped vehicles unlessspecial sensor layouts and signal processingsoftware are used.

Microwave Radar • Typically insensitive to inclement weather atthe relatively short ranges encountered intraffic management applications.

• Capable of direct measurement of speed.

• Multiple lane operation available.

• Installation maintains integrity of pavementsurface.

• Doppler sensors cannot detect stoppedvehicles.

• Installation and maintenance typicallyrequires lane closure

• Installation requires pavement cut.

• Improper installation decreases pavementlife.

• Installation and maintenance require laneclosure.

• Wire loops subject to stresses of traffic andtemperature.

• Multiple detectors usually required tomonitor a location.

• Detection accuracy may decrease whendesign requires detection of a large varietyof vehicle classes.

Inductive Loop • Flexible design to satisfy large variety ofapplications.

• Mature, well-understood technology.

• Large experience base.

• Insensitive to inclement weather such as rain,fog, and snow.


• Provides best accuracy for count data ascompared with other commonly usedtechniques.

• Common standard for obtaining accurateoccupancy measurements.

• Less susceptible than loops to stresses of traffic.

• Insensitive to inclement weather such as snow,rain, and fog.

• Less susceptible than loops to stresses of trafficand temperature.


Magnetometer(Two-axis fluxgatemagnetometer)

• Installation requires pavement cut.

• Improper installation decreases pavementlife.

• Installation and maintenance require laneclosure.

• Models with small detection zones requiremultiple units for full lane detection.



Table 3 – Summary of Traffic Detectors (cont’d)


Video ImageProcessing

• Monitors multiple lanes and multiple detectionzones/lane.

• Easy to add and modify detection zones.

• Provides wide-area detection wheninformation gathered at one camera locationcan be linked to another.


• Installation and maintenance, includingperiodic lens cleaning, require lane closurewhen camera is mounted over roadway(lane closure may not be required whencamera is mounted at side of roadway).

• Performance affected by inclement weathersuch as fog, rain, and snow; vehicle shadows;vehicle projection into adjacent lanes;occlusion; day-to-night transition; vehicle/road contrast; and water, salt grime, icicles,and cobwebs on camera lens.

• Requires 50 to 70 ft (15 to 21m) cameramounting height (in a side-mountingconfiguration) for optimum presencedetection and speed measurement.

• Some models susceptible to camera motioncaused by strong winds or vibration ofcamera mounting structure.

• Generally cost-effective when manydetection zones within the camera field-of-view or specialized data are required.

Active Infrared • Transmits multiple beams for accuratemeasurement of vehicle position, speed, andclass.




• Operation may be affected by fog whenvisibility is less than 20 ft (6 m) or blowingsnow is present.

• Installation and maintenance, includingperiodic lens cleaning, may require laneclosure.

Passive Infrared • Multizone passive sensors measure speed.



• Passive sensor may have reduced vehiclesensitivity in heavy rain, snow & dense fog.


• Some models not recommended forpresence detection.



The disadvantages of an inductive loop detectionsystem include:

• Disruption to the flow of traffic during installationif it cannot be coordinated with highwayconstruction or maintenance;

• Detectors cannot be effectively installed ininadequate pavement conditions;

• Heavy trucks cause pavement flexing, resulting inloop damage in poor pavement;

• Winter conditions can delay loop replacement forlong periods of time;

• Pavement rehabilitation projects often destroyloops; and

• Reliability and useful life are strongly dependenton proper installation procedures.

Table 3 – Summary of Traffic Detectors (cont’d)


Ultrasonic • Multiple lane operation available.

• Capable of overheight vehicle detection.

• Large Japanese experience base.


• Environmental conditions such astemperature change and extreme airturbulence can affect performance.Temperature compensation is built intosome models.

• Large pulse repetition periods may degradeoccupancy measurement on freeways withvehicles traveling at moderate to highspeeds.


Acoustic • Passive detection.

• Insensitive to precipitation.

• Multiple lane operation available in somemodels.


• Cold temperatures may affect vehicle countaccuracy.

• Specific models are not recommended withslow moving vehicles in stop-and-go traffic.

Source: Freeway Management and Operations Handbook (September 2003) by the Federal Highway Administration andthe U.S. Department of Transportation.

Laser Radar • Transmits multiple beams for accuratemeasurement of vehicle position, speed, andclass.



• Operation may be affected by fog whenvisibility is less than 20 ft (6 m) orblowing snow is present.




Ontario ExperienceIn Ontario, several traffic management systems thatutilize Inductive Loop Detection (ILD) technology arenot operating properly due either to improperinstallation, poor maintenance, or breakdown of theroad surface.

Volume and occupancy determination is susceptibleto errors from improper sensitivity settings, loopgeometry, and driver behaviour. Speed measurementis particularly susceptible to inaccuracies and it hasbeen found that speed data obtained from two loopsconfigured in tandem, a known distance apart,provide more accurate data. As a result, MTO hasgradually replaced single-loop stations with double-loop stations.

Due to the express-collector freeway configurationon Highway 401, the impact of loop repair on trafficflow is minimal. In most cases, the loop servicingcan be carried out when the express or collectorsection is closed for pavement rehabilitationprojects.

Video Image Detection (VID)

The utilization of video camera images for vehicledetection and data collection is commonly used inadvanced traffic control systems. A typical imagefrom a video image detector is provided in Figure 4.

A video image detection processor is a combinationof hardware and software components that extractinformation from the output of an imaging sensor.The system typically consists of the followingcomponents:

• Imaging Sensor – The imaging sensor is anelectronic camera that overlooks a section of theroadway and provides the desired imageinformation. It can use the visible or infraredspectrum, and can provide full-frame (two-dimensional) images or a series of line (one-dimensional) images.

• Video Processor – This combination of hardwareand image processing software determines thevehicle presence or passage from the imagesreceived by the imaging sensor.

• Data Processor – Performs calculations derivedfrom the presence data, such as occupancy andcount, as well as compensation andcommunications.

These components can either be separate units orcombined into one housing unit. There are two basicapproaches used in the video processor:

• Tracking – Tag and track the progress of vehiclesthrough the field of view thereby determining thetrajectory and speed of each tracked vehicle; and

• Loop Emulation – Define and monitor detectionzones on the highway to identify when trafficenters and leaves the zone.

Tracking ApproachFor VID systems employing the tracking approach,existing video signals from the monitoring systemare fed into the video imaging processor, which runsa detection algorithm based on tracking techniquesand trajectory analysis to detect stopped vehicleswithin the field of view of the camera. This approach

Figure 4 – Typical Image from VID



requires significantly more signal throughput, in thateach vehicle, in all directions and traffic lanes visiblein the image, is identified and tracked through thecamera’s field of view. It measures vehicle speeddirectly and is a potentially useful application inidentifying incidents.

While cameras can be installed on any type ofsupport, such as poles, gantries or masts, supportstability is fundamental to obtain the bestperformance of the system. To avoid maskingeffects, cameras are preferably located in a centralposition with respect to all traffic lanes beingmonitored. It is preferable that the camera isoriented with traffic moving away from the unit inorder to avoid blinding effects at night on sometypes of cameras (i.e., blooming) due to vehicleheadlights.

The advantages of tracking-based VID systemsinclude:

• Ability to provide multiple-lane coverage;

• Tracks the trajectory of a vehicle and can detectincidents if the vehicle leaves the road or changesspeed suddenly; and

• Can replace numerous in-ground inductive loops.

The disadvantages of tracking-based VID systemsinclude:

• Cameras need to be dedicated to VID purposesonly (i.e., no pan/tilt/zoom for operators’ use inscanning roadway) in order not to sacrifice dataaccuracy;

• Zone of tracking may be determined by the rangeof the camera;

• Errors caused by occlusion;

• Errors caused by severe rain, fog and snowconditions;

• Cost-effectiveness of small installations;

• Cost for structure to mount cameras – whilestructures installed for other purposes may beused, they will seldom be in the optimal locationfor the VID camera; and

• Cost to maintain cameras which includes the useof specialized equipment, such as bucket trucks toaccess the cameras and multiple staff required tomeet health and safety requirements for workingat heights.

The following issues must be evaluated whenconsidering tracking-based video image detection.

• Shadows which are projected to the front or rearof a vehicle may create false vehicles for tracking.

• Vibration, caused by unstable mounting, mayoscillate the virtual detection zone over lanemarkings resulting in erroneous data.

• Variations in ambient light, particularly during day/night transition periods, may affect data accuracyand incident detection.

• Severe fog or other similar atmospheric conditionscan filter out vehicles which may affect dataaccuracy and incident detection.

• Minor fluctuations in accuracy may beexperienced during periods of inclement weather,but generally result in only very minor aberrationsin the data stream.

Ontario ExperienceMTO’s experience with tracking-based video imagedetection at the Highway 3/Highway 401 overpassand the Highway Occupancy Vehicle Bypass Tunnelat Highway 404/Highway 401 interchange raises anumber of concerns including:

• The ability to detect incidents/queues in veryslow-moving traffic;



• Difficulty in detecting white vehicles on saltedroadways in winter due to lack of contrast; and

• False calls caused by stopped vehicles (e.g., atstop bars) adjacent to the tracking zone, requiringcareful placement of cameras to avoid suchoccurrences.

Loop Emulation ApproachVID systems employing the loop emulation approachis more common in the transportation industry andcan detect traffic in multiple locations within thefield of view of the camera. In these systems aninteractive graphics screen is used through whichthe operator is able to locate and size the desirednumber of detection zones on an image of thecamera’s field of view. Once the detection zone isestablished, every time a vehicle passes through thedetection zone, a signal is generated by the videoimaging processor software. This signal is similar tothat produced by loop detectors which can be usedto determine vehicle presence, volume, speed,occupancy, vehicle length, etc. Special purposedetection zones can also be created to identify, forexample, vehicles on the shoulder or stoppedvehicles.

Limited traffic monitoring can also be provided witha VID system. The monitoring function, however, willrequire repositioning of the camera, which willimpact the performance of the video imageprocessor in its vehicle detection mode. There istherefore a trade-off in data accuracy in combiningthe functions of vehicle detection and videomonitoring into the same processor.

Creating detection zones on the video imagerequires care to ensure that the required area of thedetection zone is not obstructed and can distinguishbetween vehicles in each lane. The effect ofocclusion, where a high-profile vehicle obstructs orpartly obstructs the view of another vehicle, must becarefully considered when selecting cameraplacement and mounting arrangement.

The advantages of loop emulation-based VIDsystems include:

• Ability to provide multiple-lane coverage;

• Placement of vehicle detection zones on the road, asreflected by the positioning of the cameras, is notlocked to a particular detection configuration. Theconfiguration can be controlled manually (by anoperator at a computer terminal) or dynamically (bysoftware) at any time, as a function of traffic flow;

• The shape of the detection zone can beprogrammed for specific applications, such asincident detection and the detection of queuelengths, that cannot easily or economically bederived by conventional devices; and

• Can replace numerous in-ground inductive loops.

The disadvantages of loop emulation-based VIDsystems include:

• Cameras need to be primarily dedicated to VIDpurposes only (i.e., no pan/tilt/zoom for operators’use in scanning roadway) in order not to sacrificedata accuracy;

• Errors caused by occlusion;

• Errors caused by severe rain, fog and snowconditions;

• Cost effectiveness for small installations;

• Cost for structure to mount cameras – whilestructures installed for other purposes may beused, they will seldom be in the optimal locationfor the VID camera; and

• Cost to maintain cameras which includes the useof specialized equipment, such as bucket trucks toaccess the cameras, and multiple staff required tomeet health and safety requirements for workingat heights.



The following issues must be evaluated whenconsidering loop emulation-based video imagedetection.

• Shadows created by vehicles which are projectedinto adjacent lanes may produce erroneous data inthe adjacent lane.

• Shadows created by a vehicle which are projectedto the front or rear of the vehicle may skewoccupancy determination.

• Vibration, caused by unstable mounting, mayoscillate the virtual detection zone over lanemarkings, resulting in erroneous data.

• Variations in ambient light, particularly during day/night transition periods, may affect data accuracyand incident detection.

• Vehicle headlights or reflections from wetpavement may be erroneously identified as avehicle and may skew occupancy determination.

• Severe fog or other similar atmospheric conditionscan filter out vehicles, which may affect dataaccuracy and incident detection.

• Minor fluctuations in accuracy may beexperienced during periods of inclement weather,but generally result in only very minor aberrationsin the data stream.

• Discrimination between closely spaced vehiclesmay affect vehicle count and occupancydetermination.

The accuracy of video image detection systems forall three primary traffic data parameters (volume,occupancy and speed) has been demonstrated innumerous site test demonstrations to be generallyless than that of inductive loops installed in a doubleloop configuration.

Ontario ExperienceCity of Toronto’s experience with video imagedetection systems includes loss of effectiveness andaccuracy with changes in weather, and calibrationproblems due to unorthodox mounting of cameras(i.e., mounted on a 44-story building adjacent to thecorridor).

Microwave Radar Detection

Microwave radar detection is a proven and reliabletechnology in some applications while it does notwork very well in other applications (refer to OntarioExperience for details). Radar is an acronym, whichstands for Radio Detection and Ranging. Microwave,is a reference to the wavelength of the transmittedenergy. There are two basic approaches that havebeen employed to manufacturing and marketing amicrowave radar detector for vehicle detectionpurposes:

• Doppler Shift – A measurement of the Dopplershift of the transmitted and received signals; and

• Time of Flight – A measurement of the differencein time between when the signal is transmittedand the time the signal is received.

Doppler Shift DetectionDoppler shift radar detectors transmit a continuouswave of electromagnetic energy. The detector isdesigned to sense the change between thetransmitted frequency and the frequency which isreceived by the detector. The difference in frequencydenotes the passage of a vehicle and is equal to theDoppler frequency produced by the vehicle speed.These detectors provide speed data and are unableto detect stationary traffic, eliminating the ability toobtain occupancy information.

Doppler shift radar detectors project a singlefootprint image onto the roadway surface. In order tocollect speed data for individual lanes, a detector isrequired for each lane mounted on an overhead



gantry. Radar units can be configured with a widebeam width to obtain average speed across multiplelanes or narrow beams to measure speed in a singlelane.

The advantages of Doppler shift microwave systemsinclude:

• Accurate speed measurement;

• Easy set-up;

• Installation does not require pavement cut; and

• Physical mounting, with respect to cameras, issimple.

The disadvantages of Doppler shift microwavetechnology include:

• Problems with occlusion and slow moving vehicles;

• Inability to detect stopped vehicles;

• Inability to visualize the detection zones madepossible with other imaging sensors; and

• Installation and maintenance requires a bucket truckand two staff members.

Time of Flight DetectionMicrowave time of flight detection measures thedifference in time from when a signal is transmittedto the time when the signal is received. Thedifference, or time of flight, can be used to detect thepresence or passage of a vehicle by comparing thistime to the time required for the energy to bereflected off the roadway surface. For this reason,these detectors can measure the presence ofstationary vehicles. Speed data can also be provided,but the accuracy is dependent on the fieldconfiguration.

Microwave time of flight detection projects afootprint onto the roadway. Some designs provide asingle zone of detection per microwave unit. Thesedevices are capable of detecting traffic in only onelane and would generally be mounted overhead on agantry. Speed determination would be measuredbased on the known or assumed length of thedetection zone over the time the detector senses avehicle presence. The variations in vehicle length,occlusion from closely spaced vehicles, and theeffective length of the detection zone can result insignificant errors in determining vehicle speed withsingle zone microwave radar detectors in much thesame manner as a single inductive loop.

A more sophisticated approach to time of flightmicrowave radar detection is to provide multipledetection areas within the projected footprint. Thezones are defined by arcs, or range slices, radiatingfrom the detection unit. These types of detectors arecapable of being mounted in a side-fire configuration(see Figure 5) to obtain vehicle data parameters inmultiple lanes. This type of configuration offerssignificant cost advantages versus single-zonedetection devices and installation of overheadgantries. However, the determination of speed in thisconfiguration is subject to the same errors asdiscussed above. Typically, speed data is provided interms of average speed which can be accurate overlarge sample sizes, but prone to errors for individualvehicles.

The advantages of time of flight microwave systemsinclude:

• Physical mounting is simple;

• Ability to provide multi-lane coverage;

• Can replace numerous in-ground inductive loops;

• Placement of vehicle detection zones on the roadis not locked to a particular detectionconfiguration, but can be defined by the users andthrough set-up configuration.



The disadvantages of the time of flight microwavetechnology include:

• Less accurate speed measurement;

• Problems with occlusion and slow movingvehicles;

• Inability to visualize the detection zones madepossible with other imaging sensors;

• Pole distance from roadway is restricted, withinsufficient right-of-way in some urban settings;

• Set-up requires steady flow of traffic;

• Fine tuning of the detectors can sometimes beproblematic; and

• Installation and maintenance requires a buckettruck and two staff members.

Microwave technology, like video technology, suffersfrom the effects of occlusion, though to a lesserdegree. The long microwave wavelength and therange-measurement capability of some microwave

detectors allows for enhanced visibility of vehicles infar lanes that are obscured by larger vehicles in nearlanes. Side-fired installations suffer the disadvantageof more difficult detection zone placement since avideo image is not presented. Careful manipulationof the microwave sensitivity parameters as well asclose observation of the detector outputs and actualtraffic flow will provide accurate data.

Ontario ExperienceCurrently, the time of flight microwave radar systemhas been employed in Ontario at urban intersections,as well as being used as a temporary vehicledetection system on freeways during construction.

The MTO’s experience with microwave radar onHighway 401 indicates that, while the presence ofstopped vehicles can be detected, there is difficultyin differentiating one vehicle from another duringstop-and-go traffic and congestion conditions. This ismainly due to the fact that the size of the detectionzone cannot be controlled, only the location. MTO’sexperience, however, shows that microwave radar iseffective as an alternative to loop detectors duringpavement rehabilitation and construction periods.Experience in urban applications supports thesefindings with the most successful deploymentssituated in mid-block locations, measuring vehiclepassage rather than presence.

4.1.3 Future Trends

Intelligent Transportation Systems are generallyinput-data intensive and transportation authoritieswill continue to seek low-cost, reliable, accuratemeans of collecting real-time traffic flow data. Whilemuch work has been done on overhead sensors,little progress has been made in finding a truereplacement for the inductive loop sensor. Whilethere are a number of non-intrusive detectorsavailable, none have shown the accuracy or lifecycle cost effectiveness of loops. The morepromising technologies appear to be microwave andvideo. Both offer accuracy approaching that of loops

Figure 5 – Microwave Detection Unit(Side-Fire Mode)



in at least some measures, and offer significantflexibility in installation. For this reason, they makeexcellent replacements for loops during constructionwhere lanes are regularly being shifted andpavement being changed.

Trends in the industry also indicate an increasinginterest in the use of technology to collect real-timetraffic flow data using vehicle probes. This approachoffers low-cost data which is particularly useful forapplications requiring information over a largegeographic area. Wide area monitoring and the useof vehicle probes are described further in Section4.1.8.

4.1.4 Standards/Interoperability

Most sensing applications employ separate sensor(s)and a microprocessor-based controller. Theinterfaces between the sensor units and thecontrollers are unique to the various sensingtechnologies and may incorporate proprietarymanufacturer protocols. From the standpoint ofoverall ITS architecture, the controller and sensor(s)can be considered as a functional unit, and hencethe interface issue only exists between the controllerand the overall system architecture.

To date, the typical approach for collecting real-timedata from sensor subsystems is to have dedicatedtrunk communications channels between the centralsystem and the outlying field controllers. The centralsystem and the field controllers incorporate customcommunication software which polls each fieldcontroller site at prescribed intervals to collect datapackets of a prescribed format. Many operatingauthorities, such as the Ministry of TransportationOntario, have specified and developed customsoftware to be used within their jurisdiction,supported by standard off-the-shelf controllerhardware such as the type 170 controller, or morerecently the Advanced Traffic Controller (ATC). MostNorth American regional traffic control systemsincorporate the collection of current traffic volume,

speed and lane occupancy data at certain intervalsfor processing by incident detection algorithms. Anumber of jurisdictions have adopted the use of theNational Transportation Communications for ITSProtocol (NTCIP) to provide a common protocol forthe collection of detector data from the field.

4.1.5 Incident Detection Algorithms

Concepts

Automatic incident detection (AID) functions arecommonly incorporated in more advanced regionaltraffic management systems. Detected changes intraffic conditions reflect the potential occurrence ofan incident. The main objective of automaticincident detection is to assist a traffic operator indetecting potential incidents, enabling the operatorto effect incident management procedures.

Types of AID Algorithms

An incident detection algorithm is a specific logicaland analytical procedure, used along with dataobtained from traffic detectors, to ascertain thepresence or absence of a capacity-reducingincident. The measures of effectiveness generallyused in evaluating detection algorithms aredetection rate, false alarm rate, and mean time todetect. When selecting an algorithm, there isnormally a trade-off between these measures ofeffectiveness. In general, the fraction of incidentsdetected can be increased only at the expense of anincrease in the false alarm rate. To shorten the meantime to detect, a higher false alarm rate will beexpected.



Algorithms Overview

Widely used algorithms employed in various trafficmanagement systems around the world include thefollowing types:

• Pattern Recognition Approach– California– All Purpose Incident Detection (APID)– Pattern Recognition (PATREG)

• Statistical Approach– Standard Normal Deviate (SND) Model– Bayesian Algorithm– AIDA

• Time Series Model Approach– RIMA, Smoothing Model– Double Exponential Smoothing (DES)– High Occupancy Algorithm (HIOCC)– Filter Model– Dynamic Model

• Catastrophe Theory Approach(McMaster Algorithm)

• Neural Network Approach (ODINN)

• Fuzzy Logic (TTI Fuzzy Approach)

• Wide Area (IDEAS, AIDA)

Pattern Recognition Algorithms compare trafficparameters between upstream and downstreamdetector stations. These algorithms rely on theprinciple that an incident is likely to significantlyincrease occupancy upstream while reducing theoccupancy downstream. Statistical Algorithms arebased on statistical analysis to determine if therecorded traffic data differ statistically fromhistorical conditions or a defined threshold. The TimeSeries Model Approach Algorithms perform

comparisons between short-term forecasts and theactual conditions, and identify calibrated deviationsas incidents. The McMaster Algorithm uses trafficflow theory and Catastrophe Models to forecastexpected traffic conditions on the basis of currenttraffic measurements for incident and congestiondetection. The Neural Network Approach uses backpropagation, hidden layer and nerve connections,and such networks exhibit learning memory and anability to address the “noise” of real world data. TheFuzzy Logic approach uses fuzzy logic decision rulesinstead of analytic control laws in traffic flowcontrol. The Wide Area detection approach is basedon machine vision incident detection schemesassociated with video image detection systems.

Ontario ExperienceExperience indicates that Modified CaliforniaAlgorithms and the McMaster Algorithm have beenrated the highest on the basis of reportedperformance, operational experience and modelcomplexity. These algorithms claim to be able toachieve a detection rate of 70% to 85%, with afalse alarm about 1% of the time4. In Ontario, theAPID (All Purpose Incident Detection) and McMasterAlgorithm have been implemented and both operateat a detection rate of about 40%, which seems to bea more realistic detection rate.

The City of Toronto has recorded similarperformance statistics for the APID and McMasterincident detection algorithms. The City of Torontoalso keeps closer tracking of auto-detected queuesand congestion than the COMPASS system.

It should also be noted that the ability of an operatorto detect incidents and congestion manually isdirectly related to the level of training andexperience of each individual operator.

4 Traffic Incident Management Handbook, Federal Highway Administration.



There are different approaches in the industry fordesign and implementation of AID systems. Theseapproaches are summarized as follows:

• Central Detection Processing – The AID algorithmresides in the central computer system wherebytraffic data from multiple detection stations can beused for incident detection.

• Local Detection Processing – The AID algorithmresides in the local controller/field cabinetwhereby only data from a single detection stationcan be used for incident detection.

• Public Domain Algorithms – These algorithms arewell used and published around the world, and canbe applied with all types of vehicle detectors.Typically, no user fees are required forimplementation. Examples are APID, California setof algorithms, HIOCC, DES.

Figure 6 – Example of RESCU Incident Detection Data

• Proprietary Algorithms – These algorithms areusually tied in with the design of the vehicledetectors and are manufacturer dependent.Typically, the cost of the software is part of thedetector cost.

Statistics show that although most ATMSs in NorthAmerica have some form of automated incidentdetection algorithm, most agencies get incidentinformation more quickly and more frequently fromother sources (e.g., operator detection – especiallythose systems with full CCTV coverage, reports frompolice, cellular telephones, etc.). Figure 6 and Table4 show the findings for the incident detectionsystem for RESCU in November 1997. For thepurpose of this document, the illustration is notmeant to evaluate different incident algorithms (theresults were based on the findings during a shortperiod of time in 1997 and algorithm performancemay vary since then), but to illustrate the differentpossibilities of detection and their number of countsof detection at that time.

Operator Detection 14

McMaster Detection

5

APID Detection

4 Combined Detection

4

McMaster False Alarms

26

APID False Alarms

44

RESCU Incident Detection November 10 – 14, 1997

Note: The intersection of simultaneous false alarms by APID and McMaster at a single station is not logged by the system.

Source: RESCU, City of Toronto.



4.1.6 Closed Circuit Television Monitoring

Closed Circuit Television (CCTV) monitoring systemshave been employed for many years to provide visualmonitoring of the freeway system. In recent years,such systems have also been used to monitorselected urban intersections. CCTV monitoringsystems are typically used for the followingfunctions:

• To confirm the presence of an incident anddetermine its nature and severity;

• To monitor traffic flow conditions; and

• To monitor field equipment operation.

CCTV equipment applied for ATMS applications isprimarily sourced from the security industry. Thisindustry continues to drive rapid advancements inimaging technology. A wide range of comparable,compact, solid-state, low-light camera and lensproducts is available at ever-decreasing costs.

A key consideration for ATMS applications is thephysical environment. The technology reviewprocess should consider various camera housing andpan/tilt configurations suitable for the relativelyharsh roadside environment. Ambient light levelsshould be considered to identify the opticalperformance requirements for night-time operation.Furthermore, given the difficulties in accessingroadside, pole-mounted cameras, considerableattention should be directed at robust configurationscharacterized by low-maintenance requirements.

Ontario ExperienceFor the Ministry of Transportation Ontario and theCity of Toronto, the CCTV camera system hasmigrated from black-and-white in the early 1990s tocolour, as camera technology developed. In recentyears, the MTO and the City of Toronto started toinstall the dome camera in addition to theconventional pole-top-mounted cameras (refer toFigure 7). As of 2006, the CCTV camera and lensspecifications of the currently installed units have thefollowing key performance requirements:

Table 4 – Summary of Example of RESCU Incident Detection

Source: RESCU, City of Toronto.

November 10th – 14th McMaster APID OperatorExclusive

Operator Confirmed Detection 9 8 14

System Declared False Alarms 26 44 N/A

Total (Detection and False Alarms) 35 52 14

Detection Rate(System detection of actual events)

39% 34% N/A

False Alarms(System detection verified as false)

74% 85% N/A

System Detection Rate(combined detection rates for both algorithms)

40% 40% N/A



Pole-top Camera Unit

• Minimum of 1.9 lux at f/1.2;

• 13 lux full video with a useable picture at f/1.2;

• 1/3", Charged Coupled Device (CCD) colourcamera;

• Minimum of 768 (horizontal) x 494 (vertical)active pixels;

• Minimum of 470 lines horizontal resolution;

• Greater than 50 dB signal to noise ratio; and

• Automatic Gain Control (AGC) backlightcompensation.

Dome Camera Unit

• 1/4" colour, inter-line transfer, solid state CCDimage sensor;

• Minimum of 768 (horizontal) x 494 (vertical)active pixels;

• Minimum illumination of 0.5 lux with 1/4 secopen shutter;

• Minimum of 470 lines horizontal resolution;

• Standard colour NTSC composite video signaloutput with an output impedance of 75 ohms; and

• Weighted signal to noise ratio shall be greaterthan 50 dB at 1.0 V p-p (AGC off).

Dome Lens

• 1/4" format zoom lens with automatic iris andspot filter;

• Minimum focal length range of 4-88 mm,providing 22x optical zoom and compensated with10x digital zoom; and

• A neutral density spot filter providing a maximumaperture of f/1.6.

In general, a CCTV monitoring system is comprisedof the following functional elements:

• Video camera unit with pan/tilt/zoom features;

• Camera housing and mounting structure;

• Communication system between the camera andthe Traffic Operation Centre;

• Controller cabinet; and

• Video monitors and camera controls in the TrafficOperation Centre.

A CCTV monitoring system, which provides fullvisual coverage of the roadway, is a very effectiveincident confirmation system. Such a system allowsthe Traffic Operation Centre operator to confirm thepresence of an incident, and determine its natureand severity with minimal delay. In addition, CCTVcan be used to scan the roadway to monitor trafficconditions, and verify field equipment is operatingcorrectly. The monitoring functions are more typical

Figure 7 – Typical CCTV Camera Typesfor COMPASS ATMS



of urban applications of CCTV, where the operator isinterested in traffic signal operations and the impactof their operation on traffic conditions within thecorridor.

To assist the Traffic Operation Centre operator toreact immediately to an incident detection alarm, theadvanced CCTV monitoring system is designed toautomatically position the camera to thecorresponding incident location upon detection of apotential incident.

Video transmission can be accomplished usingeither full-motion video or compressed video. Full-motion video is typically transmitted at a rate of 30frames per second by coaxial cable or fibre opticcable. This transmission type provides real-time videoinformation of the monitored roadway to the TrafficOperation Centre operator. However, if thecommunications medium required for full-motionvideo is not feasible, compressed video transmissioncan be used. Upon compression, the video data canbe transmitted over conventional telephone lines orcellular channels. Compressed video transmission istypically transmitted at a rate of 10 frames persecond. As such, some information will be lostbetween each picture update.

Standards/Interoperability

Several governing bodies have been involved indeveloping the standards associated with the CCTVcamera subsystem, including standards developedfor television, video signal transmission, and CCTVcamera operation.

• The National Television System Committee (NTSC)– The NTSC originally set the broadcast televisionstandards in 1953 for North American Television.When broadcasting a video signal, the NTSCstandard requires a 6 MHz bandwidth to carry29.97 frames per second of colour picture andsound information. This standard is still in usetoday.

• The Motion Picture Experts Group (MPEG) –MPEG is a working group of ISO/IEC in charge ofthe development of international standards forcompression, decompression, processing, andcoded representation of moving pictures, audioand their combination. MPEG video digitizationschemes include the original NTSC compositesignal (143.2 Mbps), along with the CCIR 601(270 Mbps) and SMPTE 240 M (1,485 Mbps)standards. Several compression schemes areavailable, i.e., JPEG, MPEG-1, MPEG-2 and Px64,which are suitable for full-motion video.

• National Transportation Communications for ITSProtocol (NTCIP) – Document 98.01.03, releasedin draft form in July of 1998, has developedcontrol requirements for the CCTV camerasubsystem, including cameras, lenses and pan/tiltunits. There are no existing standards that definehow these devices communicate with otherrelated equipment, and as a result, eachmanufacturer has developed its own protocol tomeet their particular needs. Consequently,integrating camera systems manufactured bydifferent companies requires considerable work.

Ontario ExperienceIt should be noted that with video compression, thereis a trade-off between refresh rate and image quality– the higher the refresh rate, the lower the imagequality. The experience of the MTO is that onceoperators are used to seeing full-bandwidth/motionvideo, anything less will not be well received.

Based on the City of Toronto’s experience, the pre-setfunction used for the auto positioning of cameras isa frequent source of failure for the cameracontrollers. The failure of the particular card thatprovides this function can have a large number ofundesirable affects on camera operation (i.e., pre-sets drift, failure of cards inhibit full range ofmovement on camera or causes “jerky” movement,failure of card disables all camera control, etc.).



The MTO has recently undertaken a CCTV camerademonstration to determine the following:

• Lowest level of illumination required by thecamera;

• Overall picture quality (e.g., colour, reflection, daytime viewing);

• Blooming and smear characteristics; and

• A review of available technology.

The demonstration showed that the evaluation of theimage quality of a camera is very subjective, withmany observers rating camera performancedifferently. The inability to quantify blooming andsmear characteristics also makes specification of thecameras difficult, since inferior units could beproposed which meet the defined specifications, butare unable to provide the desired performance.Based on the comments of the observers, theblooming of the cameras appears to have thegreatest effect on perceived camera performance.

The demonstration also showed that cameras withessentially the same stated specifications behavemuch differently in real conditions. The performancewas rated from good to unusable in the eyes of theobservers. To ensure that the selected camerameets the requirements of the agency, it isrecommended that the cameras be demonstrated tothe agency under field conditions. The best methodwould be to set up a permanent site where thevendors can submit their cameras for approval.

Since technology changes rapidly, cameraspecifications must be reviewed frequently to allowan agency to take advantage of the latestimprovements.

4.1.7 Call Boxes

Call boxes are located at intervals along a freewayso that a motorist can seek assistance from theoperating agency. Traditional call boxes are equippedwith specific buttons for need identification. Oncethe call box is opened, the motorist can seek help bypushing the appropriate buttons. Specific buttonscan be selected to indicate the need for anambulance, a police vehicle, a tow truck, etc.Another type of call box can be referred to as anemergency telephone box. When the motoristreaches the emergency telephone box and picks upthe telephone, he or she will automatically beconnected to an operator who can record thelocation and type of emergency response vehiclerequired.

Although a system of call boxes with codedmessage buttons is usually less expensive than anemergency telephone system which requires voicetransmission, the latter system is more popular.Direct conversation between the motorist and thesystem operator will, in most circumstances, quicklyidentify specific needs and allow the appropriateresponses to be dispatched.

A cellular emergency call box system is alsoavailable. These call boxes are connected to a 24-hour computerized response centre, which monitorsall incoming calls and dispatches services asrequested by the callers. Each cellular call box canbe powered by a solar panel with re-chargeablebattery. The cellular call box system is virtually aself-supporting system, which can be implementedwherever there is cellular coverage.

In general, the call box system is comprised of thefollowing functional components:

• Call box equipment panel or telephone hand-set;

• Solar panel with back-up batteries;



• Communications by one of the following:– regular leased telephone lines or cellular

network;– an agency owned communications cable

system; or– a radio transmitter and receiver.

Ontario ExperienceThe Ministry of Transportation Ontario no longeruses emergency call box systems due to safetyconcerns associated with their tendency toencourage pedestrian activity alongside thehighway, the additional maintenance costs theygenerate due to the harsh roadside environment, andthe potential for vandalism. The proliferation ofcellular telephones over the past decade has alsosignificantly increased the motorist’scommunications capabilities from their vehicle,thereby reducing the need and effectiveness of callbox systems.

In the recent past an emergency call box systemwas in place on the Garden City Skyway on theQEW in St. Catharines, which is a 2 km long, six-lane structure over the Welland Canal, with noshoulders. Similar systems were also installed onshort sections of Highway 400 and Highway 417 asa pilot project. These roadways sections now havefull CCTV coverage with active monitoring of theseroadway sections from a nearby Traffic OperationsCentre, significantly increasing the level ofmonitoring in these roadway sections.

4.1.8 Vehicle Probes

AVI/AVL-Equipped Vehicles

Vehicles equipped with on-board units, travelling onthe roadway, can serve as moving sensors to collecttraffic information. This type of probe vehicle hasbecome one of the key components to performmonitoring functions for advanced trafficmanagement systems. The real-time locations and

identities of the probe vehicles, once transmitted tothe operation centre, can be used together withother sources of information to determine thefollowing traffic parameters:

• Travel speeds• Travel times• Origin and destination of the probe vehicles.

Traditionally, there are two approaches to collectingtraffic parameters using probe vehicles, AutomaticVehicle Identification (AVI) and Automatic VehicleLocating (AVL). The concepts and the associatedtechnologies of these two approaches are discussedin the following sections.

Automatic Vehicle Identification (AVI)Automatic vehicle identification systems identifyprobe vehicles as they travel through a detectionarea. AVI systems typically consist of a roadsidecommunications device that broadcasts aninterrogation signal from its antenna. When a probevehicle equipped with a tag or transponder moveswithin the range of the antenna, the transponder ortag returns the identification code of the vehicle tothe roadside device. This information will then besent to a central computer system for furtherprocessing. Transponders can be further classifiedbased either on power sources or on programmableinformation.

Based on the type of power source, the followingthree classes of transponders are available:

• Active – Power to this type of transponder issupplied from an internal battery or a connectionto the power supply of the vehicle. Thetransponder responds to the signal originated fromthe roadside device by broadcasting its own signalcontaining the vehicle identification code. Assuch, this type of transponder is more reliable andhas a greater communications range.



• Passive – No internal or external power supply isrequired for this type of transponder. Theinterrogation signal from the roadside antenna ismodulated and reflected to the reader. As such,the return signal is weaker and has a shortercommunications distance.

• Semi-active – Like the passive transponder, thesemi-active transponder activates only after aninterrogation signal is received from the reader.Similar to the active transponder, a semi-activetransponder uses internal power to boost thereturn signal to the reader so as to increase thecommunications distance.

Based on the intelligence of transponders, threeclasses of transponders are identified as follows:

• Type I – This is a read-only transponder thatcontains fixed data, such as identification number.The fixed data can only be programmed orreprogrammed at the manufacturer’s plant.

• Type II – This transponder has both read and writecapabilities. Typically, some of the memorycontains fixed data such as an identificationnumber, and cannot be field programmed, whilememory such as time, data and location can beentered in the scratch pad memory.

• Type III – This transponder has extended memoryand is capable of full two-way communications.This transponder has an RS232 interface tocommunicate with extended Universal MobileTelecommunication System (UMTS) and has aninternal modem.

AVI systems have been used as a means ofcollecting travel time information as well as incidentdetection. In the Buffalo area, electronic tolltransponders (E-ZPass) are used to collect link speedinformation on select highway links for trafficmanagement purposes. The MTO is currentlycontemplating a similar deployment on the Ontario

side of the border to monitor border conditions andestimate border wait times. The trend is that futurevehicles will be equipped with 5.9 GHz transpondersunder the IEEE 802.11 standard.

Automatic Vehicle Location (AVL)Automatic vehicle location systems track thelocation of vehicles as they traverse the roadnetwork. By continuously locating the probe vehicles,travel speed can be estimated for each link on thejourney, and the overall travel time can be obtainedand monitored in the operation centre. Typically,global positioning systems (GPS) technology is usedto locate the position of the probe vehicles. As apotential source of link travel time, the data collectedcan also be used to detect incidents and determinetheir severity.

Automatic vehicle location systems are typicallyemployed by the following agencies:

• Transit agencies – to track transit vehicles so as toimprove system management and to providepassengers with arrival and delay time;

• Emergency services – for dispatching andscheduling purposes;

• Courier companies – for dispatching andscheduling purposes; and

• Vehicle manufacturer/operating agencies – totrack stolen vehicles and vehicles with inflated airbags.

Cellular Telephone Probes

An emerging trend in probe-based monitoring is theuse of cellular telephones as probes. There are twofundamental approaches to determine traffic flowdata through the use of cellular telephones invehicles. These two approaches help determine thevehicle location using equipment at the cell tower orby using the satellite-based global positioningsystem (GPS) with a receiver on the handset.



Network-Based ApproachThe network-based approach relies upon networkequipment to locate the probe. The probe could be acellular telephone or a special-purpose device usedfor location purposes. This method uses the cellularnetwork “hand-off” as cellular telephone userstransfer between cells. The “hand-off” would occuras long as the cell telephone is powered on,regardless if it is in use or not. By sampling thelocation of a cellular telephone over a period of time,the route and velocity at which the telephone istravelling can be determined. Cell sizes vary widelybased upon cellular network capacity requirements.Essentially, denser urban areas have smaller cellsizes than larger rural areas. Locating a cellulartelephone would be more accurate in urban areas.While an individual record of a cellular telephone’sposition is typically less accurate than that of acorresponding global positioning system (GPS)record, this is compensated for by the large numberof cellular telephones on any road, knowledge of theunderlying road network, and the application ofadditional network equipment that would furthernarrow down a telephone’s location using othertechniques, such as relative signal strength, timedelay or triangulation.

The ability to position a telephone within a cellularnetwork is well understood. However, to createhighly accurate traffic information, there are anumber of challenges to be overcome. Theseinclude collecting data without compromising anindividual user’s privacy, de-cluttering the millions ofdata points available into a usable data stream, andmap-matching the resulting patterns to the roadnetwork so as to measure velocity and travel time.

Full working sites, using live cellular telephone probedata, have been successfully developed in the TelAviv area of Israel, Antwerp in Belgium, andBaltimore in the United States.

Handset-Based ApproachThe handset-based approach uses GPS receiversincorporated into a cellular telephone. The GPSreceiver would locate the vehicle using a traditionalGPS receiver or an assisted GPS (AGPS) receiver.Location data is recorded at regular intervals (e.g.,every ten minutes) using on-board GPS and datarecorders. The time taken to pass through pre-determined, geo-fenced areas are then calculatedusing advanced algorithms. The AGPS receiverrelies upon the location of fixed landmarks, usuallycell sites, to improve the accuracy and acquisitiontime of the handset’s location. The location of thevehicle can then be communicated via the network,typically using the cell networks data service.

In Canada, field trials are being conducted with anumber of suppliers in developing travellerinformation services with the use of AGPS receivers.The services would use vehicle probes, who aresubscribers to the service, to collect location-baseddata, which would then be used to develop traveltime information. The information could then be usedto provide subscribers with subscription-based alerts,as well as to provide travel information via traditionalwebsites.

4.1.9 Patrol Vehicles

Patrol vehicles travelling on highway, arterial andcity roadways during their normal work assignmentcan be used to detect and confirm incidents, as wellas to coordinate with the Traffic Operation Centrefor incident management. Typical patrol vehiclesinclude the following:

• Police patrol vehicle• Service patrol vehicle• Maintenance patrol vehicle.

The primary use of patrol or municipal vehicles at anincident site is to provide for long-term closures oflanes or roads, as well as to facilitate clean-up or



emergency management services (EMS)investigations. Patrol personnel are also normallyresponsible for the proper cleanup of debris.

Service patrol vehicles are vehicles that areassigned to a roadway facility to patrol the highwayand provide assistance to motorists in need. Theyare not typically used as a primary resource tocollect traffic and incident information in regionaltraffic management systems since there are highcapital, operating and maintenance costs associatedwith patrol vehicle operation. Also, the incidentdetection times are typically long and unpredictable,depending on the number of vehicles covering thehighway.

When an incident is reported to the police or isdetected by other monitoring means, patrol vehiclescan be dispatched to the incident site to confirm thenature of the incident and provide the necessaryassistance.

4.1.10 Private Citizen Calls

Private citizen calls are becoming one of the majorsources of incident information as the number ofcellular telephones on the roadway rapidly increases.The advantages of this method include:

• Quick detection of the incident;• Low set-up and operating costs; and• Direct conversation between the motorist and the

system operator.

However, the accuracy of the data provided by theprivate citizen calls is an issue to be consideredsince many motorists are not able to accuratelyidentify the location of the incident or the directionof travel. The effectiveness of this method ofinformation collection depends on the willingness ofthe motorists to report traffic problems, and thenumber of the cellular telephones on the roadway.As a result, some traffic management agencieshave established toll-free cellular call numbers for

reporting traffic problems. This special number canbe set up to connect motorists directly to the agencyresponsible for incident management. Onedrawback is that multiple calls on a single incidentmight occur, potentially overloading the operator andthe associated cellular network. Nevertheless, it isestimated that half of all incidents reported arethrough cellular telephones.

Ontario ExperienceExperience in Ontario indicates that for this methodto succeed, it is very important to set up and run apublic campaign to inform motorists on whatnumber and who they should call to report trafficproblems. The benefits of the call-in system must beexplained to the general public.

4.1.11 Information from Other Agencies

The primary agencies involved in responding totraffic problems on highways and city roadways arethe provincial government, the municipality, police,ambulance services and the fire department. Fromthe information collection and incident managementperspective, it is extremely important to share thetraffic information among various system operatorsand notify the appropriate agencies. In particular,following the detection of an incident, basicnotification requirements should include:

• Determination of which agencies should benotified;

• Notifying the appropriate agencies;

• Providing the incident details to each agency; and

• Advising each agency of incident location andrelevant traffic information.



Typically, traffic management teams are formed toplan overall traffic management and coordinateresponse to roadway problems. These teams mayinclude the following agencies:

• Provincial government• Municipal government• Transit operators• Police department• Fire department• Ambulance services• Environmental agencies• Towing services.

4.1.12 Advanced Road WeatherInformation Systems (ARWIS)

An advanced road weather information system is anetwork of weather data gathering and roadcondition remote sensing systems. ARWIS isimplemented to inform the road agency of roadsurface, pavement and atmospheric conditions inorder to improve the efficiency and effectiveness ofwinter road maintenance. A typical advanced roadweather information system will collect and informthe operating or maintenance agencies of thefollowing:

• Atmospheric conditions (e.g., air temperature,wind speed and direction, humidity, precipitationoccurrence, visibility, etc.);

• Road surface conditions (e.g., temperature, wet/dry, etc.); and

• Subsurface conditions (e.g., temperature atvarious depths).

The system will track and report the current andforecasted pavement conditions, and advise therelated agencies.

By linking detailed weather and pavementconditions, a road weather information system canadvise the road operating agencies where and whento send the winter maintenance equipment, as wellas how to treat the surface with various de-icing oranti-icing methods. By combining informationobtained from pavement sensors and meteorologicalsensors, pavement condition forecasts can be madeto identify which portions of the roadway networkare likely to be problem locations.

Investigations conducted around the world indicatethat road weather information systems can reducethe cost of snow and ice control by assisting roadoperating agencies to be proactive in allocatingresources to deal with inclement weather.

Ontario ExperienceSince the late 1980s, Ontario’s ARWIS hascombined current and forecasted weather withobserved road conditions for distribution tomaintenance managers, municipal authorities andthe private sector around the province. In 1992, theMTO started to use roadside sensor information toenhance its decision making in winter operations. Ineffect, they have planned salting, sanding, andplowing operations based on three sources ofinformation: pavement forecasts, weather forecasts,and pavement sensor data. Given the successfulimplementation of ARWIS, MTO has expanded theARWIS system to approximately 112 sites locatedthroughout the province as of 20065.

4.2 Surface Street Control

This section provides an overview of the existingsurface street control systems, the development oftheir latest capabilities, and their interface with otherAdvanced Traffic Management Systems. For detailsrelated to the design and operation of signalized

5 MTO Maintenance Technolgy Project – 2003-2004: 8th Season, http://www.mto.gov.on.ca/english/transtek/m03-04/03-04fs.htm.



intersections, the reader is referred to OTM Book 12(Traffic Signals) which replaces the Traffic SignalsChapter of the Manual of Uniform Traffic ControlDevices.

4.2.1 Control Techniques

The coordinated operation of traffic signals toprovide progressive traffic flow on an arterial roadnetwork can be achieved using a variety of controltechniques including:

• Time-based coordination• Time-of-day control• Traffic responsive control• Traffic adaptive control.

Time-Based Coordination

Under time-based coordination, the operation of agroup of traffic signals is based on the use ofpredetermined timing plans (cycle length, split andoffset) at each intersection. These timing plans aredeveloped based on historical traffic informationusing signal timing optimization software, such asTRANSYT, PASSER, SYNCHRO, etc. Timing plans ateach intersection are selected and implementedbased on the time of day. Coordination betweenintersections is then dependent on the ability of thetime clock in each controller to maintain time in anaccurate manner.

In a time-based coordinated system, there is norequirement for a physical interconnection orcommunications link between intersections or to acentral control and monitoring system. This lack ofcommunications presents some significantdisadvantages to the operating agency, such asrequiring field staff to physically visit an intersectionto make any adjustments to the timings, and notallowing any monitoring functions to reportequipment malfunctions or the collection of real-timetraffic data.

Time-of-day Control

Time-of-day control is similar to time-basedcoordination in that predetermined timing plans areused at each intersection and implemented basedon a time-of-day schedule. The difference with thiscontrol technique is that each intersection isinterconnected with a control and monitoring systemto maintain synchronization between intersections,as well as provide a means of monitoring fieldequipment and updating signal timings from acentral location, and collecting real-time traffic data.

Traffic Responsive Control

Traffic responsive control provides an alternativeform of traffic signal control to the traditional time-of-day approach. In this control technique, real-timetraffic data is monitored. Based on the trafficpatterns detected, one of a series of predeterminedtiming plans is selected. As a result, signal timingplans are allowed to vary in response to changingtraffic patterns. Typically, under traffic responsivecontrol, real-time traffic data is collected every 5 to10 minutes with signal timing plans being selectedat a frequency of not less than every 15 minutes. Tooperate under traffic responsive control, a centralcontrol and monitoring system is required.

Any one intersection or group of intersections can becontrolled under traffic responsive control.

Traffic Adaptive Control

Traffic adaptive control represents a significantdeparture from the more traditional conceptsoutlined above. It is a control concept that allowssignal timing parameters to change continuously inresponse to real-time measurement of trafficvariables. As a result, there are no predeterminedsignal timing plans required, and timing planchanges can occur as regularly as once every cycle.To operate under traffic adaptive control, a centralcontrol and monitoring system is required.



4.2.2 System Types

Various types of surface street control systems arecurrently available in the marketplace. All offer time-based coordination, time-of-day and trafficresponsive control, while the traffic adaptive controlis only available in select systems. Surface streetcontrol systems can be categorized into one of thefollowing types:

Arterial Master Systems

An arterial master system is comprised of threeprimary components: the intersection controller, themaster controller, and a central control andmonitoring system. The intersection controller islocated in the field at every intersection, and isresponsible for the control of the intersection signaloperations on a second-by-second basis. The on-street master controller is also located in the field,and is connected to each intersection controllerwithin a control area. Each master controller isresponsible for area control functions (such astiming plan selection and/or traffic responsivecontrol), as well as the storing of alarms, detectordata and other recorded events. Each mastercontroller then reports to the central system uponcritical alarms or on an operator-predetermined ormanual basis.

Central Second-By-Second Control Systems

Central second-by-second control systems have beenavailable in the marketplace since the 1970s,utilizing a central computer to control and monitorthe operation at every intersection under systemcontrol on a second-by-second basis. In this type ofsystem, each intersection under system control isconnected to the central computer through thecommunications network with all control decisions(both intersection and area control functions) madeby the central computer. In the event of a failure of

the communications system or the central computer,coordinated operation is not possible unless the localintersection controllers are capable of time-basedcoordination.

Distributed Control Systems

With the availability of more intelligent intersectioncontrollers, distributed control systems have becomeincreasingly popular. With this system type, the localintersection controller is responsible for bothintersection and area control functions using time-based coordination techniques (with the exception oftraffic responsive control). While each intersection isinterconnected with the central system,communications with central is significantly reducedwith each intersection polled once every 5 minutesto report events (e.g., alarms, detector data, etc.)and receive commands from central (e.g., change oftiming plans, synchronize time clocks, etc.). Thisapproach provides a more failsafe type of operationin the event of a communications or centralcomputer failure and significantly reduces thesystem’s data transmission requirements, therebyallowing the use of alternative communicationsmedia such as radio.

Traffic Adaptive Control Systems

Traffic adaptive control systems and the associatedreal-time control strategies were originally developedin the 1970s and early 1980s when central second-by-second systems were common. Due to thetechnology available at the time and the processingpower required, the control algorithms were residentin the central computer with detector data beingreceived and control commands delivered to everyintersection on a second-by-second basis. Thissimilarity with central second-by-second systemsallowed traffic signal management systems to bedeveloped that offer both standard time-of-day andtraffic responsive control with adaptive controlcapabilities to be implemented in select areas ofthe city.



Of the many different adaptive or real-time systemsthat were developed in the 1970s and 1980s, onlytwo have become commonly available as acommercial product, SCOOT and SCATS. SCOOT(Split, Cycle, Offset Optimization Tool) wasdeveloped by TRRL (Transport and Road ResearchLaboratory) in the U.K. SCATS (Sydney CoordinatedAdaptive Traffic System) was developed by theRoads and Traffic Authority (RTA) of New SouthWales, Australia. More recently, considerableresearch has taken place in the area of distributedadaptive control where much of the data processingand timing optimization is carried out in the localcontroller. While the features of distributed adaptivecontrol are much the same as central adaptivecontrol, the major difference is in thecommunications requirements. Currently, distributedadaptive control systems are just emerging into themarketplace.

4.2.3 Design Considerations

In the planning and design of a surface streetcontrol system, a number of factors should be takeninto consideration.

System Capacity

To effectively manage a jurisdiction’s traffic signalnetwork, the surface street control system shouldhave adequate capacity to monitor and control theentire signal system. This should includeconsideration of both current and future traffic signalrequirements, as well as the potential to includetraffic signals in adjacent jurisdictions, asappropriate.

Traffic Control Requirements

Identification of the traffic control requirements of aroad network is a critical task in establishing thetype of traffic signal control concept (i.e., time-of-day, traffic responsive, traffic adaptive, etc.)

required. This type of analysis should include areview of traffic volume data, variations over the day,predominant land use (i.e., shopping, special eventvenues, etc.), directional split, etc.

Existing Field Equipment

The type of field control equipment in use at asignalized intersection represents a significantinvestment for a jurisdiction. It can also present asignificant constraint, and can limit the availablechoices in signal systems. As a result, existing fieldequipment and the opportunities and constraints thatthey present should be carefully considered in theplanning and design of a surface street controlsystem.

Pre-emption/Priority Requirements

The provision of pre-emption or priority control oftraffic signals for rail crossings, emergency responsevehicles, transit vehicles, etc., is an area that istypically controlled through the local intersectioncontrol equipment. Central control of this feature,however, can be involved when there are moresophisticated requirements, such as route-based pre-emption or signal priority based on requests from anAVI/AVL system which monitors vehicle location.

A system and method of centralizing traffic signalpre-emption/priority for roadway emergencyoperations provide for increased accuracy andcoordination of emergency response vehicles alongan emergency route. A centralized pre-emption/priority system receives status and locationinformation (e.g., GPS) from emergency responsevehicles via a fleet management system or dispatchcentre. As an emergency route is determined andprojected in real-time, pre-determined policies areapplied to create an overall pre-emption/priority planof traffic lights at intersections along an anticipatedroute. The pre-emption/priority plan results indirectives being transmitted to the surface streetcontrol system controlling traffic signal controllers atintersections along the route. The centralized pre-



emption/priority system may coordinate amongmany traffic management systems, which providesfor a much larger pre-emption/priority service areaincluding multiple jurisdictions.

Communications Requirements

Communications typically represents the largest costcomponent of any surface street control system overthe life of the system. As a result, it should becarefully considered in the system design. Thisincludes reviewing the communicationsrequirements of alternative systems, as well asreviewing alternative methods of providing thenecessary data transmission capacity to eachintersection. For example, second-by-second controlsystems require a dedicated wirelinecommunications network, while distributed type ofsystems can use wireless communications mediasuch as radio.

Interface to Other Systems

The management of the traffic signal network isonly one component of a regional traffic controlsystem. As a result, to be effective on a regionalbasis, a surface street control system should bedesigned using open architecture concepts to allowelectronic sharing of information using industrystandard interfaces. Examples of the type of systemsa surface street control system could interface withinclude:

• Public transit vehicle location systems for theprovision of transit priority when a transit vehicle isrunning behind schedule;

• Incident management and/or lane control systemsto select a specific signal timing plan when trafficis being diverted to an arterial corridor due to anincident on a parallel freeway;

• CCTV systems to provide video images to thesurface street control system operator in the eventof an incident; and

• Other city systems (i.e., maintenance manage-ment, GIS, etc.) to provide electronic sharing ofdata and the generation of combined reports formanagement and/or reporting purposes.

4.2.4 Lane Control Signs

Lane Control Signs (LCSs) have been usedsuccessfully on arterial streets and bridge and tunnelstructures for purposes of managing incidents,reversible lanes and other traffic managementoperations that necessitate frequent and routinechanges to lane designations. Control signs providelane condition information (open or closed) tomotorists on a lane-by-lane basis at frequentintervals along the roadway. Lane control signs arespaced at relatively close intervals and theinformation presented on them is very simple innature and easy to understand at a glance. Forinstance, “X” would indicate a closed lane while adownward-pointing arrow would indicate an openlane. The main objectives of an LCS system are to:

• Provide information on lane availability forcongestion management;

• Provide a more sophisticated level of managementfor routine and special maintenance activities(e.g., in tunnels and on bridges); and

• Provide reversible lane capabilities.

Messages Displayed on LCS

Two types of messages (regulatory and diversionary)are required to meet the above objectives. Thefollowing lists the typical symbols used.



RegulatoryX Red colour to indicate lane closed. This

symbol is also used for reversing lanes and islegally enforceable.

Green colour to indicate lane is open.

DiversionaryAmber colour, to direct motorists in the lanebelow the arrow to move one lane to the left.

Amber colour, to direct motorists in the lanebelow the arrow to move one lane to the right.

Although LCSs are proven to be effective in tunneland bridge traffic management systems and onarterials for reversible lane management, it may notbe cost-effective to install LCSs over an extensivelength of open freeway. The use of LCSs is morefrequent in Europe than in North America, whereLCSs are installed as a combined lane and speedcontrol system to increase safety.

Figure 8 – Champlain Bridge Lane Control Signs

Figure 9 – Thorold Tunnel Lane Control Signs

Figure 10 – Jarvis Street Lane Control Signs

Ontario ExperienceLCSs are currently used for reversible lane operationon Champlain Bridge in Ottawa, Thorold Tunnel inThorold and Jarvis Street in downtown Toronto.



4.3 Highway Control

4.3.1 Ramp Metering System (RMS)

Ramp metering is a method of improving trafficoperations at entrance ramps to a freeway facility byregulating the rate of ramp traffic entering thefreeway. This reduces freeway congestion andimproves the safety of the merge operation.

Ramp control signals are placed on the ramp inadvance of the acceleration lane to control the entryof vehicles. Typically, one vehicle is allowed to enterthe freeway with each green signal phase. The rampcontrol signal can be pre-set to a fixed metering rate(e.g., 2 seconds of green followed by 5 seconds ofyellow/red) or the system can be operated inconjunction with vehicle detectors sensing trafficconditions on the mainline approach and on theentrance ramp. In the latter scenario, the RMS willhave a changing metering rate that adjusts to thetraffic conditions.

The metering of entrance ramps provides amechanism for balancing upstream and downstreamtraffic flows on the freeway by controlling the rate ofvehicles entering the freeway. This can be aneffective traffic management strategy for purposesof eliminating or reducing operational problemsresulting from freeway congestion or managingtraffic flows upstream and downstream of anincident on the freeway. Ramp control also reducesthe turbulence created when platoons of vehiclesattempt to merge into the mainline traffic. Reducedturbulence in the merge zones has been found toreduce side-swipe and rear-end type collisions.

The benefits of a ramp metering system include:

• Improved System Operation – Delay is reduced onthe freeway and increased on the entrance ramps.This redistribution of delay minimizes overalldelays to freeway users, particularly those thattravel longer distances in the freeway corridor.

• Improved Safety – The overall freeway operateswith more stable, uniform traffic flow, resulting inreductions in vehicle crashes from stop and goconditions and congested merging operations.

• Reduction in Vehicle Emissions and Fossil FuelConsumption – A reduction of fuel consumptionand vehicle emissions is realized as a result of areduced delay and number of stops, and themaintenance of more uniform speeds in thefreeway corridor.

• Promotion of Multi-modal Operation – Thegranting of preferential treatment to HighOccupancy Vehicles (HOV) at entrance ramps(allowing them to bypass the ramp meteringsignal unimpeded) can promote travel mode shiftsand reduction of single-occupancy vehicles.

Techniques

Ramp metering systems vary in sophistication andcapabilities. The design of the system should bebased on existing traffic conditions, the amount ofoperational improvement desired, and the costsassociated with installation, maintenance andoperations. Typically, there are three types of trafficcontrol strategies: fixed rate, traffic responsive, andsystem responsive.

• Fixed-Rate Control – The fixed-rate control strategyis the simplest form of ramp metering. With thistype of control, the traffic signal holds andreleases vehicles in accordance with a fixedmetering rate. The metering rates are selectableon a time-of-day/day-of-week basis. The use ofdifferent metering rates allows the system toadjust to variations in traffic flow throughout theday. The metering rates are calculated on thebasis of historical data relating ramp flows, trafficdemand and capacity of the freeway. In general,fixed-rate control is not recommended except as afailure mode.



• Traffic-Responsive Control – Unlike the fixed-ratecontrol strategy, traffic-responsive metering isdirectly and immediately influenced by themainline and ramp traffic conditions during themetering period. The metering rates arecontinually adjusted on the basis of data collectedby detectors on the mainline of the freeway andon the ramp, as well as the capacity of theadjacent freeway section. There are two principaltraffic responsive strategies used to determinemetering rates. Demand-capacity control uses thereal-time comparison of upstream volume anddownstream capacity to select metering rates.Occupancy control measures the density of thetraffic flow in terms of the occupancy at the rampentrance and on the mainline of the freeway. Foreach level of occupancy measured, a meteringrate can be extrapolated from predeterminedvalues of occupancy and metering rates to adjustto different flow conditions.

• System-Response Control – System-responsivemetering combines individual ramps into a systemso that the metering rates of each ramp can beestablished with the objective of maximizingmainline traffic flow. The metering rates of eachramp are based on the relationship betweendemand and capacity over the controlled sectionof the freeway. In an integrated traffic responsivesystem, a linear programming technique is used tocalculate a set of integrated metering rates foreach ramp. The system will calculate the optimalallowable entrance ramp volumes subject to thefreeway capacity, allowable mainline volume andallowable ramp volume constraints.

System Components

A typical ramp metering system includes thefollowing components (refer Figure 11):

• Ramp Metering Signal – a standard 3-section (red-yellow-green) signal head;

• Local Ramp Controller; and

• Advanced Ramp Control Warning Signs (with orwithout flashing beacons) – an advance warningsign to indicate the ramp is metered and/or a signto advise the vehicle to stop at the stop line (e.g.,“Stop here on red”).

Depending on the purpose of the control strategiesutilized, the following additional components couldbe included:

• Demand Detector – located immediately upstreamof the ramp metering signal stop line;

• Passage Detector – located immediatelydownstream of the ramp metering signal stop line;and

• Queue Detector – located upstream of the signalnear the ramp entrance to detect excessive back-ups on the ramp.

Design Considerations

Properly designed and well-managed ramp meteringcan be a cost-effective strategy for reducingcongestion on freeway systems. However, rampcontrol is not a cure-all for freeway trafficcongestion. Issues of design and operations mustfirst be addressed before implementing any meteringsystem.

• Traffic Diversion – Diversion strategies attempt todecrease entrance ramp demand, generallyresulting in some diversion to other routes. Whenramp metering is used, a proportion of thefreeway-entering traffic will be required to wait atthe on-ramps before being allowed to proceedonto the mainline. Instead of waiting, somemotorists may choose not to use the freeway atall, to enter it from another location, at anothertime of day, or to use public transit. This traffic,



made up of drivers who take alternate routes,times or modes of transportation for some portionof their trips to avoid metered ramps, is called“diverted traffic”.

When diversion strategies are used, additionalcapacity, including alternate routes, time periods,or modes of transportation (i.e., public transit,carpools) should be available in the corridor. Inorder to prevent congestion on alternate routes, itmay be necessary to apply such techniques as re-timing of traffic signals, installing a trafficresponsive signal system, adding turn lanes atintersections, reversible lane operation, and/orroad widening.

• Non-Diversion Strategies – Non-diversionstrategies attempt to accommodate full trafficdemand with metering rates that are adjusted notonly on the basis of demand and capacity, but onramp queue length as well.

• Ramp Geometrics – Ramp designs should providefor adequate storage of waiting vehicles, adequateacceleration distance, and merge area beyond themeter. Appropriate steps must be taken to ensurethat non-freeway bound traffic on adjacent localstreets is not adversely affected by ramp meterqueues. The most common technique used toprovide for, or increase storage space, is toincrease the number of lanes on the ramp beforethe meter. This can be accomplished by re-stripingor reconstructing ramps to allow for two or morelanes. In this case, the meters release vehiclesfrom two lanes at a time. Downstream of themeter, the vehicles merge into one lane beforeentering the freeway.

• Equity – Ramp metering often benefits the long-distance motorist more than the short-distancemotorist. Benefits to long-distance motoristsinclude reduced travel times and increasedaverage travel speeds due to decreasedcongestion on the mainline. Increased congestion

Figure 11 – Signals for Ramp Metering



on adjacent local streets due to ramp queues anddiverted traffic may result in longer travel times forthe short-distance motorist. The use of non-diversion strategies is one way of dealing with thisdisadvantage.

• Public Acceptance – The implementation of aramp metering system must be preceded oraccompanied by a proactive public relationsprogram. The objective of such a program wouldbe to inform the public of the following:

– the basic reasons for implementing the system(recurrent congestion, inefficient use of thefreeway system, etc);

– a realistic expectation for the system usersincluding reduced delays and user costs; and

– the alternative choices available to the systemusers.

Although the benefits of ramp metering aremeasurable system-wide, they may not be easilyrecognized by motorists who experience a fewminutes delay at an entrance ramp. A successfulpublic relations program will explain the difficultiesof mitigating freeway congestion problems, and thecost-effectiveness of traffic management techniquessuch as ramp metering. The most common methodof disseminating information on ramp meteringsystems and their benefits is through brochures, TV,radio, and promotional videotapes.

Ontario ExperienceThe QEW Mississauga Freeway TrafficManagement System began operations in 1975. Atpresent, the controlled freeway section spans about19 km and contains 62 vehicle detection stations onthe mainline, ramps and arterials. The rampmetering system encompasses 6 interchanges with10 metered ramps. Each on-ramp has queue,demand and passage detectors installed to monitoron-ramp traffic during the morning rush-hour period.The ramp controller has the capability to operate

independently of the traffic control computer in atime-of-day mode or mainline occupancy traffic-responsive mode. Any failure in the central computersystem will not cause a complete stoppage of theramp metering operation. The ramp metering systemcan be controlled either manually by the operator orautomatically by the central computer, whichcoordinates ramp control logic for operation in asystem responsive mode.

The ramp metering system for QEW adopts a non-diversion approach. That is, the ramp meteringsystem in Mississauga attempts to accommodatefull traffic demand with metering rates that areadjusted not only on the basis of demand andcapacity, but on ramp queue length as well. Ingeneral, the system operates automatically undersystem responsive control, typically from Monday toFriday, from 6:30 a.m. to 9:30 a.m. Under theautomatic ramp control, the computer will determinewhen, and if, a ramp control will be turned on, basedon a pre-defined schedule, as well as the volumeand occupancy threshold values of the detectorstations.

4.3.2 Access Control

Access control is the application of control devicessuch as traffic signals, signing and gates to controlvehicle access to a freeway. The objective is tobalance the demand and the capacity of the freewayso as to maintain optimum freeway operation andprevent operational breakdowns. In particular, if themetering rate is required to be very low over asustained period, it may be necessary to physicallyclose the ramp with automatic gates or manuallyplaced barriers. As such, the entrance ramp to thefreeway should only be considered for closure underthe following conditions:

• Insufficient storage space on ramps, wherebyvehicles waiting to enter the freeway interferewith surface street traffic;



• When the optimal metering rate to preventdemand from exceeding capacity on the freewayis so low (i.e., two vehicles per minute) that itwould be more practical to close the ramp in orderto prevent congestion on the freeway; and

• Substandard merge at ramp ends.

Ramps can be closed on a temporary basis, on ascheduled basis, or permanently. Temporary closureis very common for maintenance, construction andincident management activities. Ramp closureduring peak periods and openings at off-peak timesare typical for addressing recurring congestion. Itcan be considered as a form of ramp metering byimplementing complete closure of the ramp atcertain periods of the day. Permanent ramp closurecan be a result of changes in the freeway systems.Concrete barriers are recommended to close theramp in the case of permanent ramp closure.

Ramp closures are typically implemented with thefollowing traffic control equipment:

• Barriers – automated gate or manually placedbarrels or cones; and

• Signing for upstream traffic.

Ontario ExperienceA gate is installed at the entrance of the JamesonStreet on ramp to the Gardiner Expressway for boththe eastbound and westbound directions. Thepurpose is to improve traffic operations on theGardiner Expressway by prohibiting entering trafficat this location and balance traffic between theGardiner and Lake Shore Boulevard during peaktraffic periods through predetermined, time-of-dayclosures of a mechanical physical barrier.

Current operation of the Jameson Gate is as follows:

• Eastbound restriction 7:00 a.m. to 9:00 a.m.• Westbound restriction 3:00 p.m. to 6:00 p.m.

4.4 Regional Traffic Control

4.4.1 Concepts

Regional traffic control is intended to coordinate andintegrate the operation of a freeway with the surfacestreets and arterials that surround it. Regional trafficcontrol utilizes highway control concepts andsystems and surface street-control concepts andsystems to better manage the entire freeway/arterial corridor in order to improve their safety andoperational efficiency and reliability.

The integration of multiple systems within a regionalcontrol strategy provides for real-time sharing ofinformation and coordination of traffic managementactivities between agencies, thereby enhancingsystem interoperability and enabling a regionalapproach to traffic management. Potentialapplications in regional traffic control that supportthe concept of inter-agency coordination and thesharing of information include:

• Regional ATIS Database – for the provision of real-time information and the sharing of travellerinformation in order to provide a single point ofaccess for traveller information for use byinformation service providers (ISPs), users (e.g.,via the internet), etc.

• Coordination of Signal Timing – for coordinatedoperation of traffic signals across jurisdictionalboundaries. This can also be applied to freewayramp-metering control such that the surfacestreet/arterial signal system can change timingparameters to accommodate traffic diverting fromthe freeway, and vice versa, allowing the freewayto adjust metering rates based on trafficoperational conditions on the adjacent arterials.

• Emergency Management System Reporting –allows the sharing of incident/emergency statusand traffic management information. This couldinclude the highway control system and surface



street-control system supplying information to anemergency management centre so thatappropriate routes may be identified for routingemergency response vehicles and/or evacuations.

• Sharing of Displayed DMS Messages – to informadjacent and nearby system agencies of warningmessages posted in response to an incident orother problem.

4.4.2 Centre-to-Centre Communications

The integration of two or more systems involves theimplementation of interfaces and communicationslinks between systems for purposes of exchanginginformation, control status, and/or controlcommands. This centre-to-centre communicationstypically involves peer-to-peer communicationsbetween multiple systems, which may be co-locatedwithin the same physical Traffic Operation Centre(TOC) or in entirely separate TOCs. The centre-to-centre communications facilitates seamlessexchange of data between multiple systems andagencies. Examples include data exchange betweenarterial and freeway systems, with municipalities, aswell as between Ontario and U.S. agencies whendealing with border-related information. It isnecessary to identify the number of systems to beintegrated and where they are located, and then toidentify the communications links between thesesystems. Communications system requirements arediscussed under Section 4.7.

To allow for integrated operation, agencies shouldensure that system designs are compliant with theITS Architecture for Canada, with adoption of opencommunications protocol. The ITS Architecture forCanada and associated standards facilitate sharingof information and coordinated operations throughuse of common data elements across agencies.

4.4.3 Technologies and Strategies

The most appropriate technologies and strategies tobe implemented will depend on the degree ofintegration agreed upon between agencies, and howthe information exchanged will be utilized. Variouslevels of interaction are possible, including:

• Communicate via phone, fax;

• Share system data/video on “view only basis”;

• Share system data/video control during specialevents;

• Share system data/video control day-to-day;

• Share system control during emergencies, orduring periods when the Traffic Operation Centreis not staffed; and/or

• Share some/all system functions.

4.4.4 Integration of Legacy Systems

Regional integration will often involve a mix of newsystems and legacy systems. A legacy system is, bydefinition, currently operational and may representthe latest technology embodying the principles ofopen architecture, or may be a closed system withproprietary interfaces, databases and protocols, aswell as limited documentation. In the latter case (i.e.,proprietary), full centre-to-centre integration may notbe possible, in which case a simpler systeminterface (e.g., separate workstation, e-mail/browserinterface) may be the most appropriate approach.Even if the legacy system is not completely “closed”,as compared to an “open” system architecture, itmay still be necessary to add a data exchangeprotocol to the legacy system to facilitateinformation exchange.



4.5 Traffic Information Dissemination

A motorist can be provided with a variety of real-time, travel-related information, including advisoryinformation related to traffic, transit and roadwayconditions. Current traffic data from ATMSapplications is a critical component of the data setrequired for a comprehensive advanced travellerinformation system (ATIS). ATIS provides informationregarding road and traffic conditions that can beobtained either prior to departure (i.e., pre-trip) orwhile en-route.

4.5.1 Pre-Trip

A motorist can be provided with detailed trafficinformation prior to their departure, using a variety ofmedia. This information can be used by the motoristto assist in making departure time and modechoices, travel-time estimates, and route decisions.Tailored information can be obtained based on real-time interactive response to a traveller’s request orbased on a submitted traveller profile. Variousmethods of receiving pre-trip information aredescribed below.

Fax and Pager Services

Fax and pager services are used to provideinformation to subscribers regarding current roadand traffic conditions, including scheduled andunscheduled events. Information is provided basedon preferences indicated by the subscriber. Somesubscribers prefer to have updates at scheduledtimes (i.e., every 15 minutes, or every hour), whileothers prefer to be provided updates based on theoccurrence of an event (i.e., whenever a collisionoccurs).

Subscribers to fax and pager services can includethe media, transit authorities, commercial fleetcompanies, or other traffic authorities. MTO and Cityof Toronto systems both employ fax and pagerservices.

TV, Cable TV, and General Commercial BroadcastRadio

A motorist can use TV, cable TV, as well as generalcommercial broadcast radio as a source of pre-triptraffic information. These information sources havelarge broadcast ranges and some have specifictimes dedicated to providing traffic information.Usually, traffic information is broadcast only duringrush hours, and is limited to a brief summary of thetraffic conditions in the entire broadcast area, withemphasis on any events that greatly impact trafficflow.

As pre-trip sources of traffic information, thesetechnologies provide information that is relevant toroute and mode choices, as well as estimating traveltimes.

Internet

The use of the internet is impacting all areas ofindustry, including transportation. The internet isspecifically of interest to the transportation industryas a method for providing pre-trip travellerinformation services.

Websites can be set up to provide motorists withinformation on current traffic conditions, activetraffic events, and scheduled traffic events. Inaddition, recent or real-time images from CCTVcameras can be provided through the internet andaccessed by a motorist to personally evaluatecurrent traffic conditions. The information providedthrough the internet can be used to assist in makingmode choices, travel time estimates, and routedecisions.

Recent advances in internet applications for travellerinformation include the use of push/pulltechnologies and personalized travel information ona subscriber basis. The trend to wireless internet



access using cellular telephones, personal digitalassistants and palm-top personal computers willfurther extend the role of the internet as a mediumfor comprehensive pre-trip and en-route ATIS.

Ontario ExperienceThe MTO and the City of Toronto systems bothprovide real-time traffic information and access toCCTV camera images through their respectivewebsites.

Interactive Telephone

Interactive telephone utilizes motorist input toprovide personalized traffic information through anautomated voice information system. For example, amotorist can phone a dedicated telephone number(e.g., City of Toronto’s “RoadInfo” line) and requestinformation regarding a particular roadway sectionor area by selecting from a menu using the touch-tone keypad of their telephone or through a voicerecognition system. Due to the interactive nature ofthis application, the traffic information provided canbe specifically relevant to the selected area. Itshould be noted that interactive telephone can beused by a motorist for pre-trip information for routeand mode selection, or can be accessed using acellular phone for en-route advisory. Recently 511has been dedicated for the provision of travellerinformation in Canada. This provides one commontelephone number across North America thatmotorists can use to obtain up-to-date travellerinformation.

The City of Toronto recently included the “RoadInfo”interactive telephone system as part of their travellerinformation services that provide motorists with real-time traffic information.

4.5.2 In-Vehicle

Motorists within a vehicle can obtain real-time trafficadvisory information through a variety of methods.This information may be obtained within the vehiclethrough audio in the form of Highway AdvisoryRadio (HAR) or general commercial radiobroadcasts. In addition, information can be obtainedand used as input into a vehicle navigation systemfor purposes of route selection and guidance.

Highway Advisory Radio (HAR)

Highway Advisory Radio (HAR) systems can use adedicated AM frequency (530-1710 kHz) or licensedFM frequency (88-108 MHz) for extended-rangebroadcast. The higher bandwidth of FM frequenciesoffers an improved signal, with a shorter rangewhen compared to AM frequencies.

The wattage used for broadcast affects the range ofthe signal. Therefore, a low wattage transmitter canbe used to provide specific information relevant to asmall area of coverage. This information may includecollisions or roadwork in the area. Alternatively, ahigher wattage transmitter can be used to provide agreater amount of information to a wider area. Thisinformation can be limited to events that have majoreffects on traffic, or can include all minor and majorevents, but for a number of areas.

There are a number of issues associated with theimplementation of HAR. Availability of frequency is asignificant challenge since there is no dedicatedfrequency allocated for HAR use within Canada. Thisis further complicated when the location of the HARstation is in close proximity to the U.S. border,requiring federal agencies from both countries toagree on the proposed frequency. Licensing isanother complication when the use of licensed radiois proposed. It can be very difficult for a publicagency to hold a license for the use of a dedicatedAM or FM frequency. The use of low-powertransmitters can negate the need for a license.However, use of low power reduces the area of



coverage of a transmitter, requiring the use of shortmessages to ensure a driver hears a completemessage at least once. Alternatively, multipletransmitters can be used to increase the area ofcoverage, but this will require coordinated operationbetween transmitters to ensure drivers hear aconsistent message as they pass betweentransmitters. These complicating factors, combinedwith the limited ability to make the HAR messageinteresting to listen to (typically recorded bymaintenance or traffic operations personnel with noradio broadcasting experience), do not make HAR anattractive option for disseminating travellerinformation.

General Commercial Broadcast Radio/TV

Commercial radio has a large-range broadcast andlimited time dedicated to providing trafficinformation. Therefore, the information provided bycommercial radio generally includes a briefsummary of the traffic conditions in the entirebroadcast area, with emphasis on any events thatgreatly affect traffic. Commercial radio stationsthroughout Ontario provide regular traffic reports,particularly in urban areas and during peak trafficperiods.

Commercial radio traffic reporting presently servesto be the most commonplace and far-reachingmeans of disseminating traffic information tomotorists en-route. While commercial traffic reportsare readily available to a widespread audience, thereare limitations that arise from their means ofsourcing traffic information. Typically, the informationis assembled from multiple sources which caninclude:

• Verbal communication with authorities• Cellular telephone callers• Traffic monitoring using aircraft.

The multiple sources can make the data difficult toverify when there is conflicting information. Detailson locations of incidents can be suspect and currentinformation on the status of an incident difficult to

obtain since few sources will report when anincident has been cleared. As a result, accuratereporting can be difficult. Providing a single sourceof accurate and reliable traveller information tobroadcasters on a real-time basis can significantlyincrease the effectiveness of this disseminationmedium.

With increasing market penetration of in-vehicle andpersonal communications and entertainmentsystems, there will be increasing opportunity forreception of commercial TV broadcasts en-route.This will provide the motorist with en-route access todedicated commercial TV traffic broadcasts.

It should be noted that Europe and Japan, as well asCanada to a lesser degree, have recently embracedDigital Audio Broadcast (DAB) and Satellite Radio,which provide a significant communicationsbandwidth and quality improvement over FM signalcapabilities. DAB and Satellite Radio provide useraccess to both audio and digital information (e.g.,financial, traffic, sports, etc.), as well as a number ofuser services enhancements. These services arecommencing in Canada and receivers are readilyavailable on the market. The digital broadcast formatsupports the delivery of a wide range of broadcastservices into the vehicle. The European andJapanese ITS programs have pursued thedevelopment of standards for the delivery of trafficinformation. To date, there has been little progress inthis regard in North America.

In-Vehicle Guidance

A vehicle can be equipped with a route selectionand guidance device using Original EquipmentManufacturer (OEM), after market or portabledevices. Route selection and guidance informationmay also be obtained from an Information ServiceProvider (ISP), such as General Motor’s OnStar(r)program. Route selection and guidance can beeither autonomous or dynamic. Autonomous routeselection and guidance relies on static information



stored in a Geographic Information System (GIS),and typically selects a route based on shortestdistance or travel time. Dynamic route selection andguidance utilizes dynamic information, and cantherefore be responsive to current traffic, weatherand road conditions.

The information used for dynamic route selectionand guidance can be obtained through dedicatedshort-range communications (DSRC) or extendedrange two-way communications. The use of DSRCrequires a number of roadside antennas to provideperiodic traffic information updates. Due to the shortrange of DSRC, the traffic information provided islimited. Extended range two-way communicationstechnologies include cellular, spread spectrum andmicrowave, and are able to provide a greater rangeof communications. Therefore, extended range two-way communications technologies are better suitedto this application than DSRC applications. It shouldbe noted that the information provided for dynamic

route selection and guidance can either be obtainedby a traveller based on an area-wide broadcast, orcan be personalized based on preferences providedby the individual.

Significant work in dynamic route selection andguidance is currently being done, particularly inJapan. However, there are few initiatives currentlyunderway in Ontario.

4.5.3 Roadside Dynamic Message Signs

Dynamic message signs (DMSs) are used to provideadvisory information from the roadside to en-routemotorists. They are typically custom-manufactured tothe owner’s specification, and hence acomprehensive knowledge of the state oftechnology is critical to successful procurement. Acomplete discussion of DMS applications, designprinciples and technologies are addressed in OTMBook 10 (Dynamic Message Signs).

Figure 12 – MTO Overhead Gantry-Mounted DMS



4.5.4 Role of Private Value-AddedService Providers

Currently, the public sector tends to control thedissemination of traveller information through theirroadside/fleet infrastructure (e.g., vehicle detectors,incident detection algorithms, CCTV, dynamicmessage signs, traffic operation centres, transitmanagement centres, emergency dispatch centres,etc.). The private sector tends to be involved in morebroadly-based dissemination devices throughcommercial media broadcasts, as well as the use ofvarious personal communications devices to whichtraffic conditions and traveller information can bebroadcast. Information can be conveyed free ofcharge via broadcasting, with revenue to be soughtthrough advertising in the form of a wholesaler, orcustomized for selling to end-use customers basedon a fee-for-service arrangement in the form of a

retailer. Allowing access of the information by value-added service providers affords the opportunity forthe public data to serve as a potential revenuestream.

In the United States, examples of public-privatepartnership business models for ATIS includeSmartTrek led by the Washington State Departmentof Transportation (DOT); AZTech, led by Arizona DOTand Maricopa County DOT; TransGuide, led by TexasDOT, City of San Antonio and VIA MetropolitanTransit; Guidestar, led by Minnesota DOT; andTravInfo, in San Francisco Bay Area led byMetropolitan Transportation Commission. Typically,information is conveyed free of charge to the public,using the internet and telephone as the primarymethods of dissemination. Where contracts arearranged with the media, information is alsoconveyed through radio and television, and in some

Figure 13 – MTO Roadside-Mounted (Cantilever) DMS



cases, the press. Revenue, if any, is secured fromadvertising on the website, subscriptions forcustomized information services, and sponsorshipsfor ongoing financial contributions.

4.6 Computer System

4.6.1 System ArchitectureFunctional Requirements

Central/Distributed Processing

Software applications serving each other in adistributed environment are the most efficientmethod of utilizing resources in a computer network.Besides having the best economy of scale, theclient-server arrangement allows the softwareapplications to reside where they are mostappropriate. Security, however, is a major concern,especially with respect to access to servers, andshould be well-planned in order to avoid unauthorizedand inadvertent misuse.

Operator Interface Requirements

The software should provide a simple, point and clickgraphical user interface (GUI), where successiveavailable actions are intuitive and easily identified.Easy-to-understand icons should be used instead ofcharacter acronyms. Available options should beclear to every level of user and should be followedby a confirmation request in order to minimize risk oferror. A multi-purpose interface with passwordprotection should be developed so that users haveaccess only to functions they have been authorizedto use.

External Interface Requirements

Interoperability should be considered whenimplementing software applications. Any inter-process communications mechanism (e.g., CORBA)selected should be capable of easily integrating intoany network topology, as well as any computer

platform. In addition, the database management toolchosen should permit cross-platform access tosupport heterogeneous network topology, as well asthe convenient generation of external reports.

Communications protocol standards (e.g., NTCIP)should be adopted in all possible situations whencommunicating to field devices. Failing that, allcommunications protocols to field devices must beopen as a minimum requirement. Both of theserequirements promote ease of maintenance, as wellas cost savings in field equipment purchase andcentral software development.

4.6.2 Software Functional Requirements

Incident Management Function

Incident management consists of two functionalareas – incident detection and incidentmanagement.

Incidents are detected either by the execution of anautomatic incident detection (AID) algorithm ormanually by an operator.

Incident management monitors the transition of theincident state as a result of external stimuli. Thesestimuli can include operator monitoring of incidentclearance activities (CCTV), confirmation and returnto normal traffic operations. During the life cycle ofthe incident, the incident management softwareshould act as a decision support tool for the operatorin recommending actions or identifying alternatives.Regardless, all system-initiated actions must bevalidated by operator confirmation.

Traffic Response Strategy Function

Traffic response strategies should also be system-initiated, providing the operator a decision supporttool to help in the selection of the most appropriatestrategy. This decision support system can either bebased on a pre-determined response plan or an



algorithm (i.e., rule-based). Pre-determined responseplans are the easiest to develop, but can becomeonerous to maintain as the system expands on botha geographical and functional basis.

Any type of traffic response should be based on theincident location and the condition or severity of theincident. Information can be disseminated to thepublic via DMS or other media, such as fax orinternet. When conducting a traffic response, theoperator must be guided, as well as reminded ofcritical reactions in a step-by-step procedure.Tracking of operator actions should be automaticand used for future analysis. In COMPASS andRESCU, the operator’s decisions are supported bythe system-recommended response. In most cases,no manual response is required.

Network Traffic Managementand Optimization Function

The system should have the capability to includemultiple highways as part of its configuration. Tooptimize operation, the traffic response strategyshould be easily adjustable by the operator toaccount for incidents or congestion in eachindividual highway, a change in highway geometry(e.g., single versus express/collector), availability ofequipment, or other unforeseen circumstances.

When multiple roadways are dealt with by severalTraffic Operation Centres (TOCs), exchange of trafficdata and equipment status is necessary in order tocoordinate operations near the jurisdictionalboundaries. This loosely coupled data exchangemechanism allows the systems to preserve theirindependence, yet react to incidents beyond thecapacity of an individual system.

In the case where operations may be taken over byanother TOC, full configuration and acquisition oftraffic data and equipment status from the first TOCmust be made available to the second TOC. Dataexchange is therefore more frequent and networkcommunications bandwidth must be readily availableto support increased data transmission.

Traffic Diversion Function

Diverting traffic from one portion of a highway toanother (e.g., collector to express or vice versa)requires an accurate incident or congestiondetection algorithm and operator confirmationprocedure. Traffic diversion is usually recommendedas a result of a confirmed incident, ongoingcongestion, or road work. An operator must beprovided with relevant traffic conditions in thesubject highway segments, as well as a method ofverifying the incident before a traffic diversionstrategy is initiated.

Ontario ExperienceIn Ontario, a passive (soft) diversion approach isadopted where the traveller is provided informationon traffic conditions ahead, with no directionprovided on which route to take, except in the caseof a full road closure.

Device Control Function

Enable and disable functions are required totemporarily remove potentially faulty devices fromthe system. Once recovered, a device should be ableto announce its normal state by automaticallyresponding to a periodic status poll from the centralcomputer. In this case, reset and/or initializecommands should be dispatched to re-initialize thedevice for normal operation.



Controls related to testing a device should also bemade available for reasons of routine maintenance,as well as for those uncertain faulty states. Forexample, testing light-emitting diodes (LEDs) on aDMS on a routine basis may be necessary to ensurecontinual normal operation.

Manual control and/or download of the deviceaspects and parameters may be necessary fromtime to time. This may include cases where thecurrently displayed DMS message or a DMS librarymessage needs to be modified.

Traffic Information Database

A traffic information database invariably includestraffic data, event logs, as well as systemconfiguration data. This traffic information canfurther be categorized as current or historical.Displaying current data and status is an importantpart of traffic management, and therefore must beexecuted without delay. In addition, access to thisdata or status by an external system should beallowed in a controlled manner to support otherpossible applications.

Archiving and retrieval of this information should beperformed both on a regular, as well as on an on-demand basis. Historical data should be kept forfuture data analysis.

Data Warehousing

With the abundance of traffic information beingcollected by various agencies from their respectivesystems, the creation of a central or commonaccess point for data should be considered. Theconcept is to provide a common point where anyagency can access up-to-date and accurate trafficinformation from multiple systems. In this approach,each agency supplying information continues tooperate and maintain their systems according totheir needs and requirements. They also have theoption of choosing what data they wish to share and

in some systems are given the option of selectingthe agencies with whom they wish to share with.This approach to data warehousing allows for easyaccess to existing data, systems and operatingprocedures, while allowing each agency to continueto use the systems that best meet theirrequirements.

The advantages of a common access point fortraffic information include:

• Provide a single resource for multiple agencies toobtain traffic information;

• Achieve consolidation of traffic information datafrom one source (i.e., access point), which couldthen be used in an off-line mode for transportationplanning or research purposes;

• Allows agencies supplying information to controlwhat information they share and with whom;

• Ability to automatically update agency website(s)using “real-time” traffic information; and

• Improved data security of the support databasesby utilizing only data elements that are directlyrelevant to traffic information and devoid ofpersonal or private information, as well as throughthe use of firewalls and other security measures toprevent unauthorized access to the database.

It should be noted that the data warehousingconcept is not intended to encroach onto theexisting operations and responsibilities of the variousagencies. It is intended for the archiving andmanagement of real-time information in a consistentform, as well as to provide easy access to a widevariety of users. The data to be collected will relateto road, traffic and weather conditions, and beexpanded to include incident data, transit services,etc. The data collected may also be used for trafficforecasting purposes.



The use of open communications protocol willfacilitate interoperability, as well as allow broadaccess of these data between physically distributedITS archives that are each locally managed, thusfacilitating virtual data warehousing.

4.6.3 Other Functional Requirements

System Start-up/Shut-down

Manual as well as automatic failover (on a dual hostconfiguration) should be made available to allow forroutine maintenance and unexpected hostequipment failure. In either case, traffic informationmust not be lost. This is accomplished by ensuringshut-down is performed in an orderly fashion andfiles and databases are adequately synchronized ona dual host/database configuration. In a single hostconfiguration, adequate storage must be reserved inthe front-end equipment to allow a retrieval processto recover data not recorded during the shut-downperiod.

Fault Monitoring

Fault monitoring is typically done on a continuousbasis. Equipment faults are captured as alarms,while a complete host computer failure shouldinitiate a shut-down procedure. Faults must thereforebe categorized to allow determination of a failover.Since different system platforms have different fatalerrors, a configurable table for fault definition andassociated action should be made available.

Logging

Logging should be performed for traffic data,system events and configuration. It is recommendedthat traffic data and system events be logged on aregular basis, while system configuration should bedone when necessary on an on-demand basis. Allevents are logged in a log file as part of thehistorical data. Additionally, critical events can be

sent to an event printer or the screen for immediateoperator attention. To facilitate the assignment ofevent outputs, destinations can be selected for eachevent definition.

Safety Issues (Conflict, Reliability/Failure Modes)

Uninterruptible Power Supply (UPS) or other similarequipment should be employed to ensure a smoothand orderly shut-down in case of an abrupt poweroutage. When a conflict can potentially causedanger to motorists, a soft interlock matrix should beimplemented in the host to ensure safety. When apiece of equipment can no longer be controlled bythe system, a default, yet safe, operational modeshould automatically be activated to ensure safety,as well as to prevent damage to the equipment.

Remote Access

The advent of the internet and recent advances inwireless technologies have provided uniqueopportunities to allow access to traffic managementsystems directly from remote and/or mobile devices(e.g., PDA). The system should be designed to allowaccess for both control and monitoring functionsusing web-based devices. The convenience that thisfeature offers to maintenance, operational andmanagement staff is significant and can beimplemented securely and easily, provided thisfeature is identified early in the design process.

4.6.4 Urban Traffic Control Functions

Due to the specific control requirements andequipment involved, surface street control systemsare typically controlled and monitored using adedicated central control and monitoring system.Electronic information exchange is then providedbetween systems (urban and freeway) to allow amore region-wide network approach to trafficmanagement.



All of the aforementioned computer systemrequirements are considered to be important aspectsof a surface street control system, and thereforeequally applicable to urban systems.

It is recommended that operations from surfacestreet control systems be separated from highwaycontrol systems, except where an exchange of trafficinformation is proven to be mutually beneficial. Insuch cases, the respective system may enhance itsfunctions to include regional traffic control, or trafficinformation dissemination.

Besides the aforementioned urban traffic controlfunctions, equipment and intersection monitoring,and data archiving and retrieval for traffic analysisfunctions are important aspects of the surface streetcontrol system functions.

Ontario ExperienceA typical example of a regional traffic control systemis the COMPASS system, currently operational in theProvince of Ontario. An example of a surface streetcontrol system is the York Region CTCS (CentralizedTraffic Control System). All software functionalrequirements described earlier are implemented inthese systems. It is especially important that thesefunctions continue to support larger areas, as well asprovide enhanced services due to highway or roadgeometry changes. Therefore, as an applicationrequirement, the software functions described aboveshould allow for growth in terms of servicecoverage, as well as for adaptation of futurefunctional enhancements.

4.7 Communications System

ATMS applications can draw from the full suite ofwireline and wireless communications technologiesand services available in the rapidly evolvingcommunications industry. In some cases, the ATMSdeployment integrates a variety of communicationsmedia in order to deliver system functionality in acost-effective manner. Accordingly, it is important

that the system definition and design processemploys the services of suitably qualifiedcommunications engineering staff with anunderstanding of the current and emergingtelecommunications technologies, products,services, standards and regulatory environment. Thisinput is instrumental in analyzing communicationsoptions.

4.7.1 Transmission Requirements

The communications network is designed to connectthe various field components of the trafficmanagement system to the Traffic Operation Centre(TOC), as well as to disseminate traffic informationto outside agencies. The various types ofsubsystems connected to the TOC include data,video and voice signals from the individual fieldequipment, such as dynamic message signs, CCTVcameras, emergency telephones, etc.

Regional Traffic Control Data Requirements

Communications networks for regional traffic controlsystems should be designed to support their varioussubsystems. Each subsystem has uniquerequirements, and these should be addressed duringthe design stage of the communications network.

The requirements for each of the existingsubsystems discussed below are specific to theCOMPASS system, but are typical of most ITSimplementation projects. The implementation ofNTCIP protocols may change the communicationsrequirements from those listed.

Dynamic Message Signs (DMSs)DMS communications is between the DMS masterat the TOC and the individual DMS controllers in thefield, and include the following message types:

• Poll for status information of current message• Command messages• Download new messages to the library.



During normal operation, the DMS master polls eachDMS every 30 seconds for status. If the DMSrequires new messages to be transferred to it, statuspolling is interrupted until the message transfer iscomplete. The DMS communications scheme isbeing upgraded to NTCIP using Ethernet, whichrequires all new controllers to support both theexisting and NTCIP protocols.

A complete discussion of DMS applications andtechnologies is provided in OTM Book 10 (DynamicMessage Signs).

Vehicle Detection Systems (VDS)VDS communications is between the traffic datamanager system at the TOC and the individual VDScontrollers, which monitor detector loops. The trafficdata manager system polls each VDS controllerevery 20 seconds for summarized data. The VDScontroller functions are integrated with theAdvanced Traffic Controller (ATC) which isconnected to the TOC over an Ethernet channel onthe data ring.

Camera Control (CC)CC communications is one way only between theTOC and the field unit to allow operator control ofcamera functions such as pan tilt and zoom. Cameracontrol data is multi-dropped on a single channel, soonly one channel per data ring is required. At theTOC, camera control can be handled by using eitherthe standard video switch control or it can beintegrated with the operator’s graphical userinterface (GUI). If the operator GUI interface is used,Ethernet communications is utilized using the samechannel as the VDS communications. The Ethernetcommunications scheme requires the CC functionsto be integrated with the ATC controller units. Forcameras using digital Ethernet communications, theTOC control functions are integrated with the videoencoders/decoders.

Ramp Metering System (RMS)RMS communications is between the RMS masterlocated at the TOC and the individual RMS fieldcontrol units to monitor operations and control rampmetering functions. RMS functions are integratedwith the ATC field control unit. The RMScommunications are combined on the same channelas VDS.

Queue Warning System (QWS)Queue warning is designed as a standalone systemwith no requirement for monitoring or interventionfrom the TOC. QWS communications is betweenfield control units requiring each ATC to beconnected by an Ethernet link. A link to the TOC canbe provided for central monitoring and downloadingof data which can be achieved using either a serialor Ethernet link. The speed of the connection to theTOC will depend on the cost associated withproviding the communications link.

Other MTO Operation CentresEach MTO operation centre should be allocated aconnection to the central computer located at theTOC and a camera control link.

The following is recommended for communications:

• Camera control• Low speed• High-speed (Ethernet)• Centre-to-centre data sharing.

Maintenance YardsEach maintenance yard should be allocated aconnection to the central computer located at theTOC and a camera control link.

The following is recommended for communications:

• Camera control• Low speed• High-speed (Ethernet)• Video and data sharing.



Future SubsystemsIn addition to the current subsystems, support for thefollowing future services should be provided:

• Advanced road weather information system(ARWIS)

• Truck inspection stations, including weigh-in-motion (WIM)

• Toll tag readers• Highway advisory radio (HAR) messaging• Vehicle-to-roadside communications (VRC)• Inter-agency data, such as RESCU and 407 ETR.

It should be noted that the above future subsystemdata requirements have not been identified.Therefore, it is important that the communicationsdesign includes additional capacity and provides fora flexible range of data interface methods. Theseshould include the ability to provide:

• TCP/IP and NTCIP protocols• DSRC roadside-to-vehicle communications• Standard TIA-232 interface• Standard TIA-422 interface.

Surface Street Control Data RequirementsCommunications networks for surface street controlsystems should be designed to support the controland monitoring of traffic signal controllers located ateach intersection. There are various types of controlsystems available on the market, which havedifferent communications requirements including:

• Arterial master systems• Second-by-second control systems• Distributed control systems• Traffic adaptive systems.

Each system requires a communications linkbetween the operation centre and each intersectionin the system. The communications links are two-way, low-speed, point-to-multi-point circuits. The typeand frequency of communications depends on thesystem selected. Traditionally, traffic systems haveused either agency-owned twisted wire pair cable or

leased circuits (two or four wire) from the telephonecompany. The option of using digitalcommunications service (DCS) is also available fromthe telephone company.

Arterial Master SystemsThese systems have two levels of communications.A master controller is connected by dedicatedcircuits to multiple controllers on a channelcommunicating on a second-by-second basis. Eachmaster is connected to the operation centre overstandard telephone dial-up lines.

Second-by-Second Control SystemsThese systems require second-by-second control andmonitoring of each intersection. The circuits arededicated multi-point circuits with multiplecontrollers per channel.

Distributed Control SystemsThese systems are designed such that the localcontroller controls the intersection, reporting statusinformation to the operation centre every 5 to 60seconds. The communications circuits are dedicatedmulti-point circuits with multiple controllers perchannel using a TIA-232 interface.

Traffic Adaptive SystemsTypically, these systems require second-by-secondcontrol and monitoring of each intersection. Thecircuits are dedicated multi-point circuits withmultiple controllers per channel. There are howeverseveral distributed traffic-adaptive systems in variousstages of development, where the local controllerprocesses the real-time traffic data and determinesits control strategy. The communicationsrequirements of this type of distributed controlsystem are not defined at this time.

The implementation of NTCIP protocol may changethe communications requirements from those listedabove.



Video Requirements

The video network is used to transmit CCTV imagesfrom the field to the TOC. MTO requirements are fullmotion video signals, which can be provided byusing analog or digital video systems. Recently,digital video transmission has been used for variousprojects, indicative of recent trends in CCTVtechnology. The design of the video transmissionsystem should be such that all video signals areavailable simultaneously at the TOC. This means thatthe video transmission system must have thecapacity to transport all video signals to the TOC.Some agencies allow remote video switching, whichreduces the capacity requirements of the videotransmission system but does not providesimultaneous access to all camera images.

Where cost effective, the video system designshould be redundant to minimize the loss of videocoverage in the event of a communications failure.At the TOC, a video switch is used to distribute thevideo signals, with redundancy typically provided atthe multiplexer and by using a ring configuration inthe network topology which provides a two alternatepaths for video transmission to the TOC.

In locations where dedicated communications plantcannot be cost-effectively extended, the ability totransmit full-motion video signals may not bepractical. In these instances, the use of low framingrate/low resolution compressed video should beinvestigated. The use of compressed video howeverwill provide lower resolution and some imageresolution problems may be experienced duringcamera panning.

Adjacent Traffic Operation CentresA video link may be provided to transmit videoimages to other traffic operation centres within MTOor operated by external agencies. This can beprovided via the communications network ifavailable, or alternatively using a leased telephoneservice connection. The quality of the video image(compressed or full motion) and number of cameras

to be transmitted will depend on the coordinationrequirements between centres and the cost ofmaintaining the link. Video connections betweenagencies can often be considered as a key interface.External agencies are typically provided the ability tochoose an image, but not control (e.g., pan, tilt,zoom) of the camera.

Maintenance YardsA video link may be provided to transmit videoimages to maintenance yards via thecommunications network if available, or a leasedtelephone service connection. The quality of thevideo image (compressed or full motion) and numberof camera to be transmitted will depend on thecoordination requirements and the cost ofmaintaining the link. Typically, the maintenance yardis provided with the ability to select the video image,but not control of the camera.

Media AgenciesTo provide access to up-to-date traffic information,some media agencies have a video feed from MTO’scameras. These video feeds are not carried by theMTO’s communications network, but are fed using alicensed carrier. As a result, this requirement onlyhas an impact on the number of outputs required forthe video switch.

Voice Requirements

The voice network is used to carry conversationsbetween maintenance staff in the field and staff atthe TOC or maintenance yards. The typical voicenetwork for maintenance personnel is radio orcellular telephone. Dedicated voice circuits are notwarranted, since maintenance personnel are notalways adjacent to a cabinet when correctingequipment faults.



The voice network currently utilizes licensedfrequency radios, including hand held and mobileportables, and a base station. This network is fullyindependent of the data and video networks, andusers are not constrained as to location for use,except in areas of poor radio coverage.

4.7.2 Transmission Media

The choice of transmission media depends on thecommunications requirements of the trafficmanagement system. Highway control systems,which include both data and full-motion videotransmission, require networks with a largebandwidth. Surface street control systems typicallyinvolve primarily data transmission, which requiresvery little bandwidth. As a result, surface streetcontrol systems use leased telephone lines,dedicated twisted wire pair cable or low-speed dataradio, while highway control systems use fibre opticor coaxial communications networks.

Fibre Optic Network

The fibre optic network can be either AsynchronousTransfer Mode (ATM) based with a separate analogvideo transmission network or Gigabit Ethernetbased using digital video. The data system iscomprised of high-speed drop-and-insert datamultiplexer/switches (data nodes) strategicallylocated along the roadway to provide low-speed datadistribution to the field controllers. The data systemis designed using a ring structure to provide aredundant communications path in the event ofcable or equipment fault.

The analog video transmission network is comprisedof point-to-point single channel links and multi-channel links. The digital video transmission systemuses video encoders/decoders to transmit thecamera images over the Gigabit Ethernet networkusing standard compression techniques, such asMPEG2 and MPEG4.

Fibre optic technology provides high-quality, long-haul transmission of both data and video. The fibresystem supports all the data communicationsrequired for the traffic management system and hasthe capacity to allow for future expansion.

Data NetworkThe high-speed network utilizes drop and insert datanodes. These nodes are installed in cabinets alongboth sides of the highway and interconnected toform a ring. If it is not cost effective to install cableon both sides of the highway, a collapsed ringtopology should be used. Each data node wouldhave two sets of optical transmitters and receivers,one set for the clockwise direction around the ring,and one set for the counter clockwise direction. Inthe event of cable or equipment failure, the systemis designed to reconfigure itself to maximize thenumber of nodes connected to the TOC.

The data node network includes intelligent statusmonitoring capabilities, which allow automaticdetection and isolation of faults anywhere in thenetwork. Fibre cable and node faults are reported toa dedicated network management computer at theTOC, which logs the time and nature of the fault.This is used by maintenance staff to isolateproblems for rectification. There should be remoteaccess to this system to allow maintenance staff toobtain status information from the maintenanceyards. The network management capabilities shouldinclude monitoring of individual channel cards andremote loop-back testing.

The data nodes employ redundant systems forprotection of data integrity in the event of equipmentor link fault. Typically, redundancy is provided for theoptical and power supply cards.

The low-speed network is used to distribute the serialand Ethernet channels from the data nodes to thefield controllers located locally or remotely. Wherethe controllers are remote from the data nodes,multi-drop serial or Ethernet fibre optic modems areused.



Video NetworkThe video network uses two methods of transmission– analog or digital.

For the analog video transmission network, thesystem uses a combination of point-to-point andmultiplexed video units. For video cameras close tothe TOC, point-to-point fibre optic links are used. Forcameras further away from the TOC, multiplexers areused to concentrate multiple video signals onto onefibre. This minimizes the number of fibres required inthe cable. The multiplexers are connected in a point-to-point configuration, from the field node site to theTOC. Each camera in the field transmits its signal tothe nearest video multiplexer using a single channelfibre optic link.

To improve system availability, the cameras areconnected to the video multiplexers in an interleavedfashion. This allows every second camera to beconnected to a video multiplexer, reducing theimpact of a failure as highway coverage can still bemaintained (albeit at a reduced level).

To provide equipment redundancy for the videosystem, each multiplexer can be configured with aredundant transmitter utilizing a separate fibre pathto connect to the TOC. Upon loss of a signal, thereceiver automatically switches from the primary linkto the redundant link.

For the digital video transmission network, thecameras are connected to video encoders, whichcompress the video into a digital bit stream. Thecompression system is typically MPEG2 or MPEG4depending on the available system bandwidth. Thevideo signals are decoded at the TOC and input intothe video switch for display on the CCTV monitors.The encoders also support the camera controlchannel. The encoders/decoders are connected overthe Ethernet data network.

Fibre Optic CableThe fibre optic trunk cable is installed within aconduit for COMPASS. The cable contains bothsingle-mode (SM) and multi-mode (MM) fibres, inbuffer tubes containing up to 12 fibres. SM and MMfibres are contained in different buffer tubes.

Multi-mode fibres are typically allocated to:

• Each subsystem for low-speed datacommunications

• Single channel video links• Node-to-node aggregate data communications.

The number of fibres allocated to single channelvideo links varies based on the number of camerasalong the right-of-way. It should be noted that thesame fibre number can be used for two differentcameras, since the links are constrained from thelocal camera to the video node.

Single-mode fibres are typically allocated to:

• High-speed aggregate data rings• Video multiplexer links• Links to other agencies, TOCs and maintenance

yards.

Single-mode fibres should be allocated for futureexpansion of the system by providing fibres forpotential future data ring and video multiplexers. Thenumber of single-mode fibres generally decreasesfarther away from the TOC, as the number of videomultiplexers requiring fibres within the cabledecreases.

Twisted Wire Pair (TWP) Cable Network

The TWP cable network is primarily used for lowbandwidth applications and is made up of individualpairs of wires to provide individual circuits. Thecables are typically 19 AWG providing a range of10 km to 15 km, depending on data rate andnumber of drops on the channel. The cable provides



reliable low-speed communications. Videotransmission can only be supported over very shortdistances (less than 2 km) with low resolution. Thesystem is configured in a tree branch structure, anddoes not typically provide redundancy in the event ofcable or equipment fault. It should be noted that afailure of one device does not typically affect theother devices as in the fibre optic network.

The expansion capabilities of a TWP system arerestricted by the number of wire pairs in the cable.

The system is comprised of modems providing serialinterface to the field controllers. Each data channeluses two or four wires depending on the systemsupplier requirements.

A comparison of different land-line technologies issummarized in Table 5.

Wireless Network

Wireless networks can consist of a variety oftechnologies including:

• Data radio• Microwave• Spread spectrum radio• Cellular commercial data services• Wireless LAN.

The advantage of wireless technologies is that thehigh cost of conduit and cable installation isremoved. The disadvantages are that the networksrequire line of sight between the transmitter andreceiver, space for the antenna is required, somesystems need licensing, and the links aresusceptible to environmental conditions.

Radio propagation analysis should be conducted fora radio system installation due to the susceptibility tosite and environmental conditions.

Table 5 – Summary of Land-Line Technologies

Features Twisted-Wire Pairs Fibre Optics

Transmission Media Copper wires Glass fibres, single or multi-mode fibres

Transmission Range10 to 15 km(depending on speed)

Limited by number of drop/insert units allowed(typically 16 to 32 with a maximum spacing of20 to 30 km) in a ring, video links up to 60 km

Communications TopologyPoint-to-point, tree and branch topology Point-to-point, passive multi-drop and drop/insert

configurations

System CapacityDictated by number of pairs in the cable.Each pair supports a channel

Up to OC-48 for data, 24 video channels forvideo per fibre

Data Rates per Channel1.2 to 56 Kbps DS-0 (56 Kbps), T-1 (1.54 Mbps), Ethernet (10

Mbps), OC-1 (51.84 Mbps)

Types of InformationSupported

Data, voice, slow scan video Data, voice, digital or analog video



Data RadioThese systems provide low-speed point-to-multi-pointcommunications links. The equipment is suitable fordata communications only. The radio system requireslicensing from Industry Canada. The master antennais an omni-directional antenna with yagi antennas atthe field controller sites. These antennas can easilybe mounted on camera poles or sign trusses.

The equipment provides a large coverage area withminimal interference from other systems, since thefrequency is licensed. The number of devices whichcan be connected on a channel is limited due to themodem turn around times, which tend to be muchlonger than for standard land-line modems.

System expansion is limited by the number offrequencies available. Also, licensing for a radionetwork can take six to eight months. The projectmanager should take the time required for licensinginto consideration during the design andimplementation stage.

Microwave NetworkThese systems provide both data and video point-to-point communications links. The system requireslicensing from Industry Canada. The frequency bandutilized would depend on the application. For data,microwave would only be useful in trunkingapplications providing high-speed links (multiple T-1s) between operation centres or remote data hubs.For video, 23 GHz channels are available whichprovide single channel video transmission. Note thatthe equipment allows for reverse band data (i.e., forcamera control), but this reverse-frequency use istypically not granted by Industry Canada.

The size of the antennas for microwave linksdepends on the frequency and range required for theapplication. For the lower frequencies, the antennastend to be large, which may not be suitable formounting on camera poles or sign trusses due towind loading.

System expansion is limited by the number offrequencies available. Frequency allocation isregulated since there is a limited availability of radiospectrum, which must be shared betweencommercial, private and government users. Grantingof licenses depends on factors such as interferencewith other users, frequency availability, public good,and availability of using alternative communicationsmedia. The approval of Industry Canada should beobtained prior to proceeding with the tender of theproject.

Spread Spectrum RadioThese systems provide multi-point data and videopoint-to-point communications links. The systems donot require licensing from Industry Canada, but theequipment must be type approved. The maximumoutput power is limited, which affects the range ofthe equipment. Since the frequency band is notprotected, there is a potential for interference fromother users. The designer should be aware thatlarger margins should be used in the design sincelater installations by others may affect theperformance of the system.

The frequency band utilized would depend on theapplication. For data, the 902-928 MHz and 2.4GHz bands are the most common. The masterantenna is an omni-directional antenna with yagiantennas at the field controller sites. The number ofmaster antennas (i.e., channels) which can besupported within the same area is limited due tointerference with each other.

Cellular Commercial Data ServicesThese services provide data connection leased fromcommercial companies. As the technology evolves,the access speed is increasing, allowing the serviceto meet the needs of ITS subsystems. Theadvantage of the commercial networks is that theyprovide large coverage areas, can be rapidlydeployed, and the rate structure is distance



independent. The disadvantage is that the monthlylease costs are based on data usage so applicationswhich require large data volumes (e.g., video) maynot be cost-effective.

Ontario ExperienceThe Region of York recently implemented use ofleased commercial data services through a localcellular telephone service provider for their trafficsignal management system. Initial results are verygood, with few transmission errors and a significantcost-savings over use of leased telephone lines.

Wireless Local Area Network (LAN)A wireless LAN (WLAN) is one in which a mobileuser can connect to a LAN through a wireless(radio) connection. The IEEE 802.11 group ofstandards specify the technologies for wirelessLANs, which use the Ethernet protocol for path-sharing and include an encryption method for secureconnection to the LAN.

The system is ideal for places where a wiredconnection to the LAN is virtually impossible. Recentdevelopment in the technology allows the user ahigh-speed connection to a LAN, eliminating thehigh cost incurred by installing Unshielded TwistedPair (UTP) cables for wired connection.

Leased Networks

Leased circuits provide either low– or high-speeddata services in both point-to-point and multi-pointarrangements. The advantage of these services isthat the telephone company is responsible for theinstallation and maintenance of the system providinga high level of reliability within a very large coveragearea. The major disadvantage of leased services isthe high annual leasing costs.

For multi-point data, the leased services can supportup to 56 Kbps. Faster services such as T-1 (1.54Mbps) and Asymmetric Digital Subscriber Line(ADSL) can support high-speed data, but typically ina point-to-point configuration.

If video transmission is required, the video signalmust be digitized for transmission on the datanetwork. The provision of equivalent full-motion videowould require a minimum of 10 Mbps data stream.

4.7.3 Supplementary Communications

Telephones

Cellular telephones are often used by the public toreport incidents and traffic information to the policeand radio stations. This information can be used tosupplement the information obtained from the trafficcontrol system.

In limited applications, cellular telephones canprovide two-way communications to remotecontrollers. This medium should only be used wherefull time monitoring is not required, since the “on air”time costs would impact the cost-effectiveness ofthis type of operation.



5. Special ATMS Applications

5.1 Bridge/Tunnel Management

Due to the physical constraints and the uniquecharacteristics of bridges and tunnels, when anincident occurs traffic problems are oftenexacerbated due to the inherent bottleneckcharacteristics of the facility and lack of diversionopportunities available. In addition, there are severalconsiderations unique to bridges and tunnels thatmay require specialized control and/or managementsystems. For this reason, bridge and tunnelmanagement systems are becoming increasinglymore common involving a wide variety of trafficcontrol equipment. The double-deck Tsing Ma Bridgeand the Route 3 Tunnel in Hong Kong are two recentexamples of sophisticated bridge and tunnelmanagement systems.

With the increasing focus on security measures,particularly on bridges and in tunnels, there is anideal opportunity to leverage the significantinvestment being made in monitoring andsurveillance equipment and apply this infrastructureto bridge and tunnel traffic management systems.

5.1.1 High Wind Warning Systems

High Wind Warning Systems monitor wind speedand direction and provide high wind warninginformation to motorists when wind conditions posea potential hazard. High wind warnings are generallypart of bridge traffic management systems.

Typically wind warnings are categorized intodifferent levels, in accordance with pre-setthresholds of various parameters including windspeed, direction and persistence. Depending onconditions, response plans are implemented rangingfrom the dissemination of warning messages toapproaching traffic to the full closure of the bridgeunder severe conditions. Since the impact of high

winds will vary depending on the size of a vehicle,warning messages often target specific vehicletypes, providing warnings to large vehicles first andadvising drivers to reduce vehicle speed to minimizethe potential hazard. Depending on the conditions,the response plan may include restricting bridgeaccess to small vehicles only and ultimately to a fullclosure. Depending on the subsystems involved inbridge traffic management system, the warningmessages may be disseminated via the media,Highway Advisory Radio (HAR) and/or DynamicMessage Signs (DMS). DMS design principles andtechnologies are discussed in more detail in OTMBook 10 (Dynamic Message Signs).

Ontario ExperienceFor high wind warnings at the Burlington BaySkyway and Garden City Skyway in Ontario, thefollowing threshold values are adopted:

• When the wind speed is between 40 km/h and64 km/h, a high wind warning message is issuedto DMSs on the bridge approaches;

• When the wind speed is between 65 km/h and100 km/h, a severe wind warning is issued toDMSs on the bridge approaches; and

• When the wind speed is over 100 km/h, theSkyway is closed to all traffic and messages areissued to DMSs in the area advising motorists ofthe closure and to use alternate routes.

The warnings are displayed on DMSs locatedupstream of the Skyway prior to the last exit point.

5.1.2 Overheight/Overweight Detection

Overheight vehicles can cause significant damageto a tunnel or highway overpass, includingequipment that may be mounted to the tunnel roofor underside of the overpass (e.g., lighting fixtures,cable trays, lane control signs, etc.). The potentialdamage and related costs in conjunction with the



potential hazard to other vehicles from debris andthe resultant traffic disruption that would be causedfrom an overheight vehicle, has lead manyjurisdictions to install overheight detection systems.

Typically overheight detection systems include theinstallation of devices well in advance of the heightrestriction. The objective is to detect the overheightvehicle and alert the driver so they can divert to analternate route. These devices can range from asimple mechanical device, such as chainssuspended from an overhead gantry to moresophisticated electronic overheight detectionsystems. These devices are used in conjunction withroadside signing (both static and dynamic) to informthe driver of the overheight vehicle that they exceedthe allowable clearance and to divert to theappropriate route.

Ontario ExperienceThe Thorold Tunnel in the Niagara Region is one ofthe few tunnels in Ontario. There is no detectionmechanism at the tunnel, but the maximum heightfor vehicles to travel in the tunnel is set at 4.65 m.This meets Ontario’s current minimum heightrequirements and, for this reason, does not requireany additional signing (similar to other overpasses inOntario).

With respect to the overweight detection, allcommercial vehicles must be weighed atcommercial vehicle inspection sites located atstrategic points throughout Ontario’s highwaynetwork. High-speed weigh-in-motion (WIM)equipment may be used at select sites upstream ofthe station to check and confirm commercial vehicleweights and dimensions are within legal limits. WIMis a very effective sorting tool that helps inspectionofficers to identify problem vehicles while allowingcompliant vehicles to pass the inspection siteunimpeded.

5.1.3 Noxious Fume Detection

The enclosed environment of a tunnel presentsenvironmental challenges to ensure the tunnel issafe and free from noxious fumes and gases. As aresult, noxious fume detection is a common featurein tunnel management systems. The objective of thedetection system is to limit the build-up of noxiousfumes from vehicle exhaust, especially duringperiods of congestion or slow-moving traffic. Ingeneral, the information from the detection system isused to control tunnel ventilation.

Among noxious fumes, carbon monoxide (CO)detection is the most common type of detectionimplemented in a tunnel. Depending on the length ofthe tunnel and the complexity of the tunnelmanagement systems, other noxious fume detectionmay include oxides of nitrogen (NO

X).

Ontario ExperienceIn the case of the Thorold Tunnel, CO is the only gastested inside the tunnel on a full-time basis. Thereare four CO analyzers located in the tunnel to detectlevels of carbon monoxide. The air is analyzed and,depending on the CO levels, mechanical fans areadjusted to ensure there is an adequate supply offresh air. In addition, the tunnel crew may monitorother gases as needed with a hand-held gasdetector.

Significant cost savings can be realized in theoperation and maintenance of tunnel ventilationequipment when their operation is managed bynoxious fume monitoring systems. Therefore, it isimportant that a noxious fume detection system bereliable and accurate to ensure the safety of thetunnel and to achieve cost-effective tunneloperations.



5.1.4 Lane Control

The automated gate control system in the MasseyTunnel, which crosses the Fraser River between thecommunities of Richmond and Ladner in BritishColumbia, is an excellent example of lane control ina tunnel. In the Massey Tunnel system, horizontalswing gates were selected to provide a barrier toclosed lanes. Located in groups of three, the gates’increasing arm lengths provide a taper effect for thesafety of the high-speed traffic. The gates areutilized to control access to a reversible lane system,which enables this four-lane tunnel to operate threelanes in the peak direction of travel during peaktraffic periods.

The automated gate system in the elevated freewayin Taipei, Taiwan, is another example of usingautomated gate control for lane control purposes.Two groups of automated gates are located at eachend of the elevated freeway to control the entranceto the freeway. It is particularly useful during severewind situations when closure of the elevatedfreeway can be executed remotely from theoperation centre.

5.1.5 Traffic Control for Lift Bridges

Lift bridges are equipped with a lift span to allow thepassage of marine traffic. With the approach of amarine vessel, traffic control devices are activated tostop oncoming traffic from accessing the bridgeprior to the bridge being lifted to the fully raisedposition.

Ontario ExperienceAdjacent to the Burlington Skyway, MTO operates alift bridge within the Eastport Drive corridor thatutilizes a traffic control system. In addition, theBurlington COMPASS system has aninterconnection with the lift bridge system thatwarns motorists when the lift bridge on this alternateroute to the Skyway is closed to vehicular traffic.This provides advanced warning of the lift bridge

status, and allows motorists the opportunity ofdiverting to the Skyway rather than waiting for themarine traffic to pass and for the lift bridge to openagain to vehicular traffic.

5.2 Smart Work Zones

ATMS applications in work zones may be describedas “smart work zones”, with the objective ofimproving motorist and worker safety. In a large part,this is done by providing motorist advisoryinformation by one or more means. Although theseATMS solutions may be applied in both constructionand maintenance work zones, they are morecommonly used for construction work zones. SeveralATMS technologies that can be used in work zonesare described below.

5.2.1 Portable Variable Message Signs(PVMSs)

Portable Variable Message Signs are often used toprovide information directly related to constructionwork zones. Best practices for their use in work zonetraffic control is described in OTM Book 7(Temporary Conditions). PVMSs typically includeinformation on closures (including time and/orduration of closure), lane reductions, speedreductions, or alternate routes. PVMSs may belocated on the back of vehicles or mounted on atrailer allowing them to be moved from site to site.Due to their portability and the physical spacelimitation of the work zone, these signs are typicallymuch smaller than overhead DMSs, although theyhave similar functionality. As with other DMSs,PVMSs should be designed and placed taking intoaccount the need for sign conspicuity, legibility,comprehension, credibility, and driver response time.PVMSs must not be used to replace any devicesprescribed in the Ontario Traffic Manual. They canonly be used to supplement such devices, primarilybecause PVMSs are not fail-safe devices.



When permanent DMSs and PVMSs are used on thesame or a nearby roadway as part of a centrally-controlled ATMS, care must be taken to ensure thatthe PVMSs and permanent DMSs are operated in acoordinated manner, and that messages do notconflict – between signs or with the actual trafficconditions. The dynamic nature of the signs leadsthe public to believe that the information displayed isupdated regularly, and considerable loss of credibilityand reduction in safety may be experienced if twosigns display conflicting information. The contractorand the road authority responsible for the ATMSshould coordinate PVMS and DMS messages.

5.2.2 Highway Advisory Radio (HAR)

Highway Advisory Radio may be used to provideadvisory information to motorists as they aretravelling in their vehicles. Information may relate tomany types of situations, including work zones.Where HAR is used to provide work zoneinformation, it is typically necessary to cover only alimited geographical area. A brief description ofalternative methods of implementing HAR in workzones is provided in OTM Book 7 (TemporaryConditions). As with any real-time travel advisorysystem, the information must be up-to-date andaccurate, otherwise credibility will be lost.

5.2.3 Traveller InformationTelephone Lines and Websites

Some road authorities have found the disseminationof traveller information through telephone lines andwebsites to be an effective means ofcommunicating information to motorists onconstruction activities. The travelling public may beadvised of this service in various ways, includingbrochures, newspapers and radio advertisements. Itshould be noted that the promotion of roadinformation telephone numbers on highway signs,either static or dynamic, is not recommended, inorder to avoid driver distraction. This policy is ineffect for amber alert messages as well.

Ontario ExperienceThe City of Toronto provides a RoadInfo publicservice telephone line where callers are able to getinformation about construction and other roadrestrictions on both city and provincial roadways inToronto, as well as on provincial highways in Halton,Peel, York and Durham Regions. The information onroad restrictions, including those due to construction,is also available on the city’s website(www.toronto.ca/rescu/). The Ministry ofTransportation Ontario provides similar services,giving motorists up-to-date information on roadrestrictions via telephone hotlines and via theirwebsite (www.roadinfo.mto.gov.on.ca/english/traveller/construction/index.html). A sample of thepamphlet for road reports for both MTO and the Cityof Toronto is shown in Figure 14.

5.2.4 Radar – Speed Display Signs(Speed Trailers)

As described in OTM Book 7 (TemporaryConditions), some devices are available on themarket, which, in a combined unit, permit themeasurement of vehicle speed by means of radar,along with a sign display of the actual speedtravelled. Optionally, the sign may also display thelegal posted speed at the time of measurement.

Figure 14 – Pamphlet of Road Reports for bothMTO and City of Toronto (as of 2006)



Such signs, while not used for speed enforcement(e.g., photo radar), have been demonstrated toreduce 85th percentile speeds an additional 4 km/hto 10 km/h over any reduction that can be achievedthrough the use of static speed limit signs. This levelof success is thought to be largely due to drivers,when seeing their speeds displayed, are genuinelysurprised and reduce their speeds. Other drivers maybe uncertain whether a sign showing their speedmeans that enforcement is nearby, and may reducespeed to avoid a potential fine.

The effect of a single speed display sign in a workzone is likely to diminish as motorists traveldownstream from the sign. This may be overcome tosome degree with the use of more speed displaysigns. Regular drivers along the section of road inquestion may also become accustomed to the signs,with diminished effect, if they see no enforcement isin place. For this reason, it is desirable tosupplement such signs with enforcement from timeto time, to achieve the necessary degree ofuncertainty for drivers, as to whether they may becharged.

Ontario ExperienceMTO experience with such signs is not extensive.When used in conjunction with a legal work zone,speed limit reduction from 90 km/h to 80 km/h,use of the speed display signs was reported to resultin a 6.2% reduction in 85th percentile vehiclespeeds.

The Ontario government has introduced newlegislation in February 2005 by way of Bill 169 toamend the Highway Traffic Act. This legislationwhich focuses on improving road safety includesdoubling speeding fines in construction zones tobetter protect construction workers, and allows forvariable speed limits on designated provincialhighways to manage traffic depending on weatheror traffic conditions.

5.2.5 Queue Warning

Automatic detection of queuing due to incidents orcongestion within work zones, and theaccompanying dissemination of information via DMStechnology can serve to inform motorists ofconditions ahead and improve safety of operations.This ATMS service is particularly useful on high-speed roadways and areas of reduced visibility, suchas horizontal and vertical curves, where slow-movingtraffic may not be anticipated and stopping sightdistances are limited. More detailed information onqueue warning systems is discussed in Section 5.3.

5.2.6 Roadway Information/MonitoringSystems

Some U.S. states have used mobile trafficmonitoring and management systems in work zones,which deploy one or more vehicle detectors utilizinginductive loops, CCTV, video imaging detectionsystems (VIDs), and radar detection technologies.These are often used in conjunction with PVMSs toadvise motorists of slowing traffic speedsdownstream, providing a stand-alone system thatautomatically generates the PVMS messages.

5.2.7 Merge Control

A high percentage of work zone collisions are rear-end and sideswipe crashes, often occurring as aresult of failure to notice a lane closure or to shiftlanes at a lane closure, as well as the merging of ahigh number of heavy vehicles (e.g., trucks, bus,etc.) prior to the work zone. Merge control offers ameans of facilitating such manoeuvres andimproving safety. Several ITS merge-control productshave been developed which promote smooth trafficflow leading into a work zone by creating a dynamic,no-passing zone upstream of the construction site,which results in reduced conflicts, fewer collisions,and reduced “road rage”. The length of the dynamicno-passing zone varies with the length of the trafficbackup. Trailer-mounted, portable signs typically



consist of flashing lights and “DO NOT PASS WHENFLASHING” signs. The purpose of the system is tohave motorists merge early enough to prevent thebackups that often occur with last-minute merging.Experience with the system has proven effective,significantly reducing travel times and collision ratesin work zones. System components typically includenon-intrusive traffic sensors, interface controllers,communications devices, regulatory signboard withflashers and trailer, and solar power equipment andbatteries.

5.2.8 Work Zone Intrusion Alarms

Work zone intrusion alarms, though currently still inthe development and test phase, appear to offerpromise for improved worker safety. Intrusion alarmsdetect vehicles entering the buffer area betweenwork crews in the work area and vehicles drivingpast the work zone, providing a warning to workers.Warning time may be short (4 to 7 seconds), butcan be vital. Such alarms employ varioustechnologies, such as infrared, ultrasonic, microwaveor pneumatic tubes to detect the intruding vehicle.When the system detects an intrusion, it sounds aloud siren to warn the workers in the area.Transmission mechanisms include radio and hard-wired systems.

5.3 Queue Warning atBorder Approaches

During periods of border congestion, queues ofinternational traffic can extend long distances fromthe border causing significant safety concerns dueto the high speed of highway traffic, the potential forrear-end collisions and the associated operationalproblems at entrance and exit ramps. The queuewarning system is designed to detect slow-movingtraffic and automatically display messages topassing motorists upstream of the queue, warningthem of slow or stopped traffic ahead. The systemmonitors traffic conditions over the length of thefreeway and automatically updates the location of

the end of queue. Messages are displayed onroadside signs and the associated messages areautomatically updated or removed as queueconditions change. The signs are located in queue-prone areas of the highway corridors and atstrategic locations where visibility is restricted due tothe horizontal or vertical curvature of the road. Thesystem operates in a stand-alone fashion for quickresponse and improved fail-safe operations.However, CCTV cameras provide the ability for anoperator at a nearby TOC to monitor operations, asrequired. Figure 15 provides an illustration of thetypical elements of a queue warning system.

Ontario ExperienceMTO has deployed queue warning systems (QWS)on the approaches to the international border at thefollowing locations as shown in Figure 16:

• Highway 405 approaching the Queenston-Lewiston Bridge;

• Queen Elizabeth Way (QEW) approaching thePeace Bridge; and

• Highway 402 approaching the Blue Water Bridge.

A queue warning system has also been installed inthe high-occupancy vehicle bypass tunnel nearHighway 404/Highway 401 interchange to warnsouthbound vehicles of any incidents, queues orslow-moving vehicles in the tunnel area.

In addition to the queue warning systems, the MTOhas also deployed pole-mounted and portableroadside dynamic message signs at a number ofstrategic locations throughout the province. Thesesigns are utilized by the various regional offices toprovide traveller information relevant to construction,lane closures, incidents, etc. The signs are controlledby the local Traffic Operation Centre. Several ofthese roadside signs have been located at keylocations on Highway 401 (Windsor, London andKingston areas) and the QEW (St. Catharines) in the



event of severe delay at border crossings. OverheadCOMPASS DMS at strategic locations in the Torontoand Burlington areas have also been designated foruse to display border-related information in the eventof severe congestion.

Recently, the MTO has deployed an overheadCOMPASS DMS on Highway 401 for westboundtraffic immediately upstream of the Highway 401/Highway 402 split. The intent of this sign is toprovide advanced warning to motorists in the eventof poor road conditions or severe border congestionin the Windsor or Sarnia areas.

Figure 15 – Typical Elements of a Queue Warning System

Figure 16 – Locations of QWS in Ontario

QWS along Hwy 402at approaches to Blue

Water Bridge

QWS along Hwy 405 atapproaches to Queenston-

Lewiston Bridge

QWS along QEW atapproaches to Peace

Bridge



5.4 Rural Application

The rural environment is usually categorized byseveral distinguishing features:

• Trip distances are relatively long;

• Volumes are relatively low;

• Congestion is relatively rare, and the times andlocations vary, however, the impact may be moresevere;

• Alternate routes are few;

• High occurrence of single vehicle collisions;

• Many travellers are unfamiliar with thesurroundings;

• Highways may traverse rugged terrain in remoteareas;

• Climatic conditions can be extreme and havesignificant impacts; and

• Animals wandering onto or bounding acrossroadways present unique hazards.

ATMS applications that are frequently deployed toaddress the unique requirements of the ruralenvironment are described below.

• CCTV Cameras – to view rural roadways for trafficmonitoring and incident verification, weather androadway conditions monitoring, DMS messageverification and event management. CCTV imagescan be sent back through wirelesscommunications to an information clearinghouse,via cellular digital packet data (CDPD) and cellulartelephone signals.

• Integrated Signal System – to control signaltiming at individual signal controllers. Datacollected through monitoring components can beanalyzed and signal timings automaticallychanged.

• Route Diversion Static Signs – to definepermanent alternates to primary routes withrecurrent problems, i.e., during peak tourist season.The static signs can be supplemented with DMS,HAR, road weather information systems, or otheradvanced technologies to enhance theireffectiveness in affecting driver behaviour.Emergency detour route (EDR) trailblazer signswith PVMSs can be placed at major diversionpoints to help motorists navigate safely and in anorderly manner through the permanent emergencydetour routes.

• Vehicle Probes – to collect information on linkspeeds and travel times, as well as to detectincidents.

• Mayday System – to provide notification to aresponse centre in case of a vehicle breakdown orcollision. The emergency notification system istypically triggered by deployment of vehicleairbags and utilizes wireless communications fromthe vehicle to a call centre, with use of GPSlocation technology to automatically identify thelocation of the vehicle. Enhanced Mayday systemscan detect and transmit crash information (e.g.,primary direction of force, severity of crash, finalresting position of the vehicle, etc.) to a call centrethat subsequently contacts an appropriateresponse agency (fire, ambulance, police), andprovides them with the necessary data derivedfrom the in-vehicle Mayday system.

Rural areas cover vast geographic areas, involvingextensive distances of highways. Under theseconditions, monitoring traffic flow and detectingcongestion, incidents, weather events, etc. canpresent a significant challenge. The application of



wide area monitoring techniques using automaticvehicle identification (AVI) / automatic vehiclelocation (AVL) technologies allows the use ofvehicles travelling in the rural corridors to serve asvehicle probes and act as detection devices. Widearea monitoring techniques used in combinationwith traditional point detection devices have provento be the most cost-effective manner to provide areasonable level of coverage for rural trafficmanagement applications.

Vehicles are becoming increasingly sophisticatedwith on-board computers, AVI/AVL devices, cellularcommunications, etc. all built into the vehicleplatform to help manage vehicle operations,increase safety and provide customer amenities. Useof these in-vehicle devices for wide area monitoringpurposes presents a significant opportunity for futureapplications in rural traffic management. Anexample is in incident management where use ofthe on-board computer, AVL and cellularcommunications technology can be used to informemergency services in the event that an air bag in avehicle has been deployed.

Ontario ExperienceMTO Northwestern Region deploys PVMSsthroughout Northern Ontario to warn motorists ofunusual traffic conditions, and to inform drivers ofclosure, alternate routes, safety messages, amberalerts, etc.

Services such as OnStar® have been offered byGeneral Motors (GM) since 1997. They have morethan 3 million subscribers with OnStar®-equippedvehicles on the road. They are committed to makeOnStar® standard equipment in the full range of GMretail cars, trucks and sports utility vehicles inCanada and the U.S. by 2007. OnStar® featuresinclude alerting emergency services when air bagsdeploy, assisting authorities in locating stolenvehicles, and remotely unlocking doors when keysare left inside.

5.5 Enforcement

The effectiveness of ATMS applications in makingthe existing road systems smoother, safer and moreefficient depends largely on driver compliance.Enforcement is a critical aspect to maintaining areasonable level of compliance. To achieve areasonable balance between enforcement andcompliance, it is important that enforcement needsand requirements are carefully considered in thedetailed design of an ATMS system. This can includethe provision of enforcement areas within a roadwayfacility or the use of ATMS-related technologies forpurposes of enforcement.

A common application of technology forenforcement purposes is the use of cameras, vehicledetectors and traffic signal controller data to enforcered-light compliance at signalized intersections. Stillcameras, activated by detectors during a trafficsignal’s red interval, record the licence plate of anoffending vehicle (a vehicle which enters anintersection during a red traffic signal). Informationdocumenting the vehicle disobeying the trafficsignal is captured by the red-light camera systemand used by provincial courts in the prosecution ofoffences.

Ontario ExperienceSince November 2000, the Cities of Toronto,Ottawa, Hamilton and the Regional Municipalities ofPeel, Waterloo and Halton have operated red-lightcameras at 68 signalized intersections. Eighteen redlight cameras are rotated among these 68locations. The operation of red-light cameras atthese locations has shown a reduction in the typesof collisions associated with red light running. Thishas resulted in a reduction in the number of injuriesand fatalities due to traffic collisions at theseintersections.



6. Institutional andManagementConsiderations

6.1 Operations

Assessment of accommodation requirements forstaff and systems is necessary in order to facilitate atraffic operation centre (TOC) for ATMS. ATMS stafforganization structures that are most effective forplanning purposes are based on functionality. Thefollowing six functional areas are typically requiredfor ATMS operation at the TOC:

• Program Management• Traffic Management and Coordination• System Maintenance• Traffic Engineering• System Development• System Technical Support.

Staffing requirements based on the six functionalareas listed above typically include:

• A Manager with overall responsibility for theoperation, support, maintenance and evolution ofthe ATMS. Depending on the organizationalstructure and capabilities of the operations staff,this may be a part-time position;

• A Traffic Supervisor/Coordinator who has overallsupervision of the ATMS and the TOC;

• A Traffic Engineer who oversees the trafficoperation functions of the ATMS. There are closelinks between the traffic engineering and trafficcoordination functions, so it is feasible to have aTraffic Engineer/Supervisor position, whichcombines responsibilities for both functions;

• The System Technical Support Officer(s) whospecializes in aspects of system software,hardware and communications, but should also beknowledgeable in traffic applications functions sothat the officer can assist in all areas of control-room operations, as required; and

• Operators for incident response, trafficcoordination and operation. Agencies shouldconsider sharing operator duties with other relatedfunctions, such as dispatch, public relations, etc.,in order to provide variety and enrich the workexperience.

In assessing the systems and staffing requirementsof an ATMS TOC, operational hours need to beconsidered. The decision will depend on trafficconditions, incident frequency, fiscal constraints andcost-effectiveness. In this assessment, considerationshould be given to other agency operations centres(e.g., emergency service dispatch, roadmaintenance, disaster response, etc.) and thepotential to consolidate operations outside of normalbusiness hours. The centre-to-centrecommunications links required to implement such anapproach would also help to provide the necessarycoordination with these operational centres duringincident response, as well as provide these centreswith an operational back-up in the event of a majorsystem failure or disaster impacting the centre’slocation.

6.2 Traffic Operation Centres

6.2.1 Functional Requirements

One of the key areas to be considered for any ATMSdevelopment is the definition of appropriateorganizational structure, staff resources, physicalfacilities, and the associated funding necessary tosupport the ongoing operation of the system.Typically, there will be several different organizationsand contractors involved in the operation of any



ATMS – directly or indirectly – making use of thevarious subsystem components in an integratedmanner. In a fully developed ATMS, these activitiescould be very diverse, including:

• Emergency incident response (police, fire,ambulance);

• Breakdown service (auto clubs, towingcompanies);

• Local traffic control device operation (traffic signalsystem, ramp metering, etc.);

• Strategic traffic management;

• Roadway maintenance management (plannedlane closure coordination and public information);

• Broadcast traffic reports (radio, television);

• Targeted traffic information (auto-fax, interactivetelephone); and

• ATMS system maintenance and support(hardware, software, communications, database).

For an ATMS to be successful, the roles andresponsibilities of each agency, and theorganizational units within each agency, must beclearly defined. In some cases, this will be relativelysimple, as a clear operational mandate may havealready been provided for these agencies, either bystatute/regulation (e.g., police) or by contract (e.g.,a network manager).

The full range of activities required to successfullyplan, manage and deliver a program of trafficmanagement and motorist information services canbe organized into several distinct areas ofresponsibility as noted below. Each of these areasrepresents a logical group of activities which requirea common set of staff skills and workingarrangements, which can be defined and

independently managed (by public sector or privatecontractor) within a single organizational unit. Thefunctional requirements of each of these areas orgroups of activities are described in the followingsections.

Policy Direction

This function encompasses the policy-level activitiesthat provide the basic framework within which thetraffic management function takes place.Government policy should establish the overallmandate, direction and priorities to be considered atall levels of the decision-making process. In supportof high-level policy, decisions must be maderegarding the overall level of program fundingavailable for traffic management and, whereconsidered appropriate, allocation of funding tobroad geographic or functional areas. Differentagencies should provide input on direction, but theoverall accountability for the project should be withone agency.

Programming and Planning

Programming and planning involves determiningspecific expenditures and investment priorities withinthe ATMS program. It includes an assessment of theoperational requirements for traffic managementacross the region, in light of current public policy,fiscal situation, institutional relationships,developments in technology, traffic engineeringstandards and practice, and the performance of theexisting system. The programming and planningfunction must sustain a program of plannedoperations, maintenance and capital investment,within an approved funding envelope, and putforward annual funding allocation proposals so thatthe requirements of ATMS may be successfullyconsidered alongside other competing spendingpriorities.



On-Site Incident Response

The on-site incident response activity involves thedispatch of specially qualified personnel (e.g., police,fire, ambulance) or specialized equipment (e.g.,breakdown service, dangerous goods clean-upcrew), to respond to incidents on the road networkand the subsequent management of the incident atthe scene.

Although the initial identification of an incident maycome from a variety of sources, the responsibility foron-site incident response will remain with the police,or in the event of fire or threat of fire, with the fireservices. The ATMS operation staff will be availableto provide assistance to the police. Further details onintegration of these emergency service agencies areincluded within Section 6.3.

Consideration to incorporate motorist assistanceprograms or emergency response units into theATMS must also be made.

Traffic Operation Centre Operator Services

The traffic operation centre (TOC) operator isresponsible for day-to-day interaction with the ATMS.This function represents the first line of responsibilityfor detecting and responding to events on the roadnetwork. The service involves activities such asvisual monitoring of CCTV, responding to systemalarms, initiation of pre-planned system responses,setting special DMS/LCS response plans, andcoordinating responses with the police and localauthorities. Input of scheduled maintenance andconstruction closures, and the coordination ofclosures on the roadways, would also form part ofthe operator’s function. Activities could also includeanswering emergency telephones, if required.

Traffic Engineering Services

Traffic engineering services encompasses the trafficengineering, planning, analysis and systemconfiguration activities that are essential in thecontinuing use of the system for trafficmanagement. It involves activities such as definitionof operating procedures, planned responses toincidents (e.g., plan development, configuration ofalgorithmic response parameters), post-incidentanalysis, database configuration (e.g., input ofequipment locations), algorithm configuration, anddetermining an appropriate course of action inresponse to equipment failures. The trafficengineering services function also provides trainingto the TOC operators regarding the use of thesystem, and is also generally involved in promotingATMS and raising public awareness of the system(e.g., production of educational leaflets, TOC tours,etc.).

Traveller Information Interface

The traveller information interface function isresponsible for managing traffic data and ensuring itis available to external agencies. The informationmay be issued directly from the TOC or beretransmitted or resold by third-party informationservice providers. This function bridges the gapbetween ATMS as a provider of roadside trafficmanagement services, and the need to provide abase level of real-time traffic information to thepublic and third-party providers. This enables thedevelopment of a market for traveller information.Specific responsibilities of this task could includemarketing and promotion of the available data, andspecification of appropriate data formats to takeadvantage of emerging technologies and standards.

Network Management Services

ATMS network management services encompassesall coordination activities with contractors and otheragencies regarding operation of the roadwaynetwork. This function provides a liaison between



local authorities, police, network manager andconstruction contractors. It provides traffic data,incident information, etc. that describes the currentperformance of the roadway network. Thisinformation may be used for reporting networkperformance, and as input into road improvementfunding decisions. In addition, this functiongenerates reports on system performance andhistorical traffic data trends.

Traveller Information Service Provision

The traveller information service providers areresponsible for actively disseminating information onthe roadway network to a wider audience, using avariety of traveller-information services andtechnologies.

System Maintenance

System maintenance relates to the preventive andremedial maintenance and repair of all in-station andfield equipment, communications and systemsoftware.

Monitoring and Evaluation

Ongoing evaluation and reporting of theperformance of the system from a technical andstrategy effectiveness perspective should becompleted.

6.2.2 Spatial Requirements

The spatial requirements for the TOC must bedefined in terms of specific rooms and theirindividual functionality. Once the rooms have beenidentified, the layout of each room can beconfigured on the basis of:

• Staff allocation• Equipment allocation• Ergonomic interaction among staff and

equipment.

The following sections outline the spatialrequirements for rooms in a TOC, depending on thefunctionality typically required to accommodate anATMS of any scope and scale.

Control Room

A control room is required to house the staff andequipment dedicated to performing the major trafficmonitoring and control functions of the ATMS.Spatial requirement considerations for the controlroom are summarized below.

Consoles and EquipmentConsoles are required for the maximum number ofoperators expected to occupy the control room atone time. In addition, a supervisor console should beprovided, if required. Consoles must accommodatethe workstation equipment used by the operator,allowing the operator to access the equipment easilyand efficiently, while not blocking views of otherequipment and activities in the room. Space for freepaper work should also be provided. A cablemanagement system should be incorporated into theconsoles.

Adequate space, wall clearance and access spaceis required for any major visual display equipment tobe located in the room (e.g., CCTV monitor banks,large screen displays, model dynamic messagesigns, etc.) and other stand-alone equipment (e.g.,printers).

The layout of the equipment should support the useof this equipment and the overall functionality of theroom. Sight lines to visual display equipment shouldbe based on acceptable horizontal and verticalviewing angles from the work position of each staffmember working in the control room. Equipmentshould be placed near those accessing it mostfrequently.



Staff workstations must be within a convenientvisual and communications range, to allow forconsultation, providing advice and coordinatingresponses. If a supervisor function exists in thecontrol room, the supervisor should be able to viewall accountable staff and equipment, as well as thestand-alone visual display equipment.

LightingRooms should be provided with effective lightingdesigns. Design requirements should includevariable overhead lighting to allow operators toadjust ambient light, depending upon thecircumstances. The lighting should also be arrangedso that there is no direct glare on the terminals andmonitors. Good task lighting is required for theoperators. Walls should be coloured and textured tominimize glare on terminals and monitors. Naturallight through windows is desirable for a morecomfortable working environment, but should becarefully controlled so as not to interfere withequipment visibility.

StorageStorage space should be provided for manuals,equipment accessories (e.g., printer paper), and forstaff belongings, particularly for staff who do nothave office space elsewhere in the building.

Raised FloorA raised floor is recommended to provide cablerouting between operator consoles, computers andthe communications room.

EnvironmentProper temperature control is necessary for thecomfort of the operators and the safe operatingrequirements of the equipment.

Circulation/AccessThe layout of equipment should allow for logicalcirculation paths within the room. Proper security isrequired to prevent unauthorized access.

Computer/Communications Room

A computer/communications room (equipmentroom) is required to house the computer andcommunications equipment for the ATMS, such ascentral processing units (CPU), system consoles,communications circuit termination cabinets,modem racks, etc. Spatial requirementconsiderations for the computer/communicationsroom are described below.

EquipmentAdequate space, wall clearance and access spaceis required for the computer/communicationsequipment. If required, temporary workspace forcomputer and communications staff, as well asspace for building system equipment (e.g. airconditioners), should be provided.

Raised FloorThe room should be provided with a raised floor, forcable routing to/from the control room.

EnvironmentA separate air-conditioning and humidifying systemwith back-up may be required. Also, it is importantthat the power be conditioned and drains beprovided for moisture. An uninterruptible powersupply (UPS) should be considered a high priority.

Flood and fire detection and protection equipmentshould also be provided in the room. To minimizeequipment damage, the sprinkler system should belinked to a power shut-off so that the power isdeactivated prior to activating the extinguishingsystem.

Circulation/AccessThe layout of equipment should allow for logicalcirculation paths within the room. Proper security isrequired to prevent unauthorized access.



Situation/Visitor Room

In the event of major emergencies and disasters, asituation room is useful as a “command post” fromwhich external personnel can monitor and controltraffic. The provision of such a space can reduce theprobability of visitors inadvertently interfering withoperator actions.

It is also important to accommodate visitors andinform them about TOC operations and the rationalebehind the overall ATMS. The opportunity exists touse the situation room as a viewing room for visitors,when the room is not required for use as acommand post. Visitors could observe control roomoperations and visual display equipment from theviewing room through a glass wall withoutdisturbing the ongoing activities of the control roomstaff. In order to provide meaningful views of theequipment to visitors, the control room layout shouldbe arranged so that viewing takes place from behindthe operators.

For the command post application, close physicaland communications links are required with thecontrol room, so that the persons involved caneffectively communicate and interact with eachother. Telephones should be provided to supplementthis interaction and for interactions with externalagencies. Consideration should be given to settingup secondary monitoring/control facilities (i.e.,operator console equipment) in this room, whichwould require cabling to/from the control andcomputer/communications rooms.

Equipment, such as a front-screen projector,projection screen, slide projector and video cassetterecorder, should be provided for audio-visualpresentations to visitors. In addition, blinds over theobservation windows and variable intensity lightingare recommended.

Ontario ExperienceThe viewing rooms in the City of Toronto IntegratedTransportation Control Centre (ITCC) and GreaterToronto COMPASS Traffic Operation Centre areplaced so that the operators’ workstations face awayfrom the viewing room. The CCTV monitors andother visual displays are clearly visible from theviewing room. The size of the viewing room shouldbe sufficient to manage emergency or crisissituations where media may be involved, forexample, snow storm crisis. Both MTO and the Cityof Toronto have needed to expand their situation/visitor room space to accommodate commandcentre roles and media staff.

Offices and Ancillary Space

Office space should be provided for all staffoperating the ATMS from within the TOC. Ancillaryoffice support space for washrooms, kitchenettes,storage, closets, photocopying and other necessitiesfor 24/7 operation should also be provided.

6.2.3 Proximity Relationships

After the spatial requirements have been defined,proximity relationships define which spaces shouldbe close to, or far from, each other. Basic proximityrelationships, which could apply to the spacesdescribed above, are shown in Figure 17.

Figure 17 – Basic Proximity Relationships

Computer/CommunicationsStaff Offices

Traffic/ControlStaff Offices

Entrance/Reception

Computer/Communications Room

Control Room

Situation Room



The major proximity relationships depicted in Figure17 are as follows:

• The control room and the computer/communications room of the TOC should be inclose proximity, and preferably adjacent, to eachother. Either horizontal or vertical proximity isacceptable for this relationship.

• The situation room should be adjacent to, andlocated on, the same horizontal plane as thecontrol room.

• Offices of control staff and traffic engineeringstaff should be near the control room, and officesof computer and communications staff should benear the computer/communications room.

6.2.4 Traffic Operation Centre Design

Control Room Specialized Equipment

The following specialized pieces of consoleequipment are standard within the control room:

• CCTV camera monitors• Telephones• Camera control equipment• Call switching equipment• Video/graphics display monitor• Voice recorder• Faxes• Video cassette recorders (VCRs).

Workstations should be provided for the number ofoperators required for the control room. Servers andnetwork equipment should be provided to containand manage the capacity of information required forthe TOC. Server and network equipment should belocated in a secure room with proper ventilation tomaintain desired temperatures.

The design of a TOC should incorporate the spatialrequirements as discussed above under the controlroom, computer/communications room, andsituation/visitor room (Section 6.2.2). The designshould include access control equipment to allowoperators to open security doors from theworkstation.

CCTV Monitor/Large Screen Display Unit

Physical requirements for display units are based onthe associated needs of the display system in termsof image size and resolution. A large screen displayunit should provide the capability of displaying threemain types of information and combinations:

• Graphical information, such as maps anddiagrams;

• Textural data, such as freeway/arterial controlinformation; and

• Video images in the form of CCTV camera feeds.

In order to size the display unit, the distancebetween the operator console and the display unithas to be determined. Designs for ITCC andCOMPASS TOC were based on a 2.5 m to 3 mseparation between the operator consoles and thedisplay wall.

Image resolution for large screen display units reliesheavily on three factors:

• Resolving ability of the average human eye, whichhas been shown to be 1 minute of arc in the fieldof vision;

• Distance from which the image is to be viewed;and

• Size of the image being viewed.



The required value of resolution for a large screendisplay unit is 794 pixels in 125 cm of imagesurface height. Commercially available display unitsof 1,024 pixels horizontal by 768 pixels verticalshould be used as minimum standard.


• The user should develop and clearly communicatemandates for the functional responsibility groups.

• Retrofitting an existing building may be cost-cutting, but it can be disadvantageous to workaround existing infrastructure.

• The size and vertical positioning of a video displayshould be optimized and should take ergonomicsinto account.

• The size and position of a workstation canobstruct the viewing area of the video display.

• Logic should be applied for the placement ofshared devices/areas, such as a printer andworkspace, to make the user-equipmentrelationship within the room efficient andconvenient.

• If there are several operational components to aTOC, all the employees should be introduced tothe TOC at the same time to enhance teamworkand curb individual work.

• The user should ensure adequate command/emergency areas exist for handling majorincidents.

6.3 Interaction with External Agencies

6.3.1 Centre-to-Centre

For the operation of an integrated ATMS, theprovision of a centre-to-centre communicationsnetwork is essential to facilitate exchange ofinformation between agencies (e.g., policecomputer-aided dispatch [CAD] systems), andprovide joint monitoring and control of field devices,as appropriate. This enables any agency to monitorconditions on other agencies’ facilities, and toimplement coordinated responses to incidents andother changes in operating conditions when needed.

As an option, the co-location of agency operationscentres can reduce the need for centre-to-centrecommunications and help to facilitate effective inter-personal communications, improve inter-agencyinteraction and interoperability. The experience ofagencies with co-location in the past, however, hasidentified a number of issues relating toincompatibility between agencies on technical/operational/procedural aspects, exchange ofsensitive information, security, labour issues, etc.

6.3.2 Incident Management Plan

ATMS-supported incident management plans areused to reduce the impact of non-recurrentcongestion and incidents. The benefits ofimplementing an incident management plan arederived from the resulting reduction in incidentduration. These benefits include:

• Improved safety by facilitating quicker emergencyresponse and reducing secondary incidents;

• Savings in lost time and vehicle operating costs;and

• A reduction in the amount of harmful emissions.



The success of incident management plans dependson clear communications and a supportive,interactive relationship between the ATMS operatorand the emergency service agencies. Much of thebenefit to be derived from incident managementplans is the savings in detection and response timefor emergency service agencies. This benefit isrealized when the incident is detected quickly andemergency services are able to respond to anincident already knowing the exact location, the typeof incident, their responsibilities, and therefore, thenumber and type of response crews needed. In thisrespect, ATMS can play a significant supportingrole.

The integration of incident management capabilitieswith commercial vehicle tracking assures fastertreatment of incidents involving dangerous goods.

The Need for Pre-Determined Plans

Pre-determined incident management plans shouldbe developed to facilitate responses to a variety ofanticipated conditions. Incident management plansshould identify the roles and responsibilities of eachemergency service agency involved, commandstructures to organize these agencies, responsemethodologies, and paths of communication.

Wherever possible, pre-determined incidentmanagement plans should also identify diversionrouting around anticipated incident locations. Whilethis may be more common in a freeway incidentmanagement scenario, arterial applications may usepolice control and modifications to traffic signaltiming to influence routing.

Plans should be developed with, and communicatedto, all agencies involved to clearly delineate rolesand responsibilities. Pre-determined incidentmanagement plans should be periodically reviewedby these agencies to ensure that objectives arebeing met in the most efficient manner.

A realistic and comprehensive pre-determinedincident management plan will reduce responsetime, reduce incident duration, improve safety, avoidcommand conflicts, and reduce the potential for thedeployment of inappropriate resources.

Who Needs To Be Involved?

Development of incident management strategiesshould involve discussions with a number ofagencies, including police services, fire services,ambulance, agencies responsible for the removal ofdangerous goods, emergency patrol vehicleoperators, towing and other road clearance services,and communications outlets such as the media.Table 6 describes the roles of the various emergencyagencies.

Ideally, the groups outlined in Table 6 should formpart of a formal incident management team used toformulate policies, as well as plan, maintain,implement and perform post-incident reviews ofincident management plans. These groups shouldwork within the context of an inter-agencyagreement that delineates and assigns on-site andcoordinating command responsibilities andcommunication structures.

Determining Appropriate Response Levels

Information on incident type, location and severity iscritical to determining the appropriate response. Theplan needs to establish what types of information arecritical, what are the reliable sources of theinformation, and how they should be collected andstored. Inadequate and/or inaccurate informationmay result in the wrong emergency service agencybeing deployed, or the initiation of an inappropriateresponse level.

By reviewing incident response levels for past events,incidents can be categorized into severity levels.Severity levels will vary according to the number ofinjuries, the number of lanes blocked, the anticipated



Agency Role

Police Services (OPP/Local) • Often first emergency agency on scene

• Usually act as central command authority and manage/command theincident through to its clearance

• Minimize personal injury through applying basic medical care

• Assess need for additional emergency services

• Control access to and from the scene

• Direct the clearance of the incident

• Close a portion or all the roadway (if necessary)

Fire Services • May act as central command authority

• Minimize personal injury through applying basic medical care

• Provide fire suppression for incident and secondary fires

• Extricate persons trapped in vehicles

• Contain and control flammable, combustible, and dangerous goods


Ambulance • Minimize personal injury through advanced on-site medical care

• Perform medical needs assessments

• Assist with extrication

• Transport of patients to appropriate medical facilities


Towing • Remove vehicles and debris from scene


• Assess need for heavy removal equipment

• May be dispatched directly or through contract service provider

Road Maintenance • Remove debris from scene

• Make emergency repairs to guide rail, electrical, etc.

Motorist Assistance Programs • Provide roving or on-call services

• Provide traffic control at incident scene

• Detect, verify, and clear minor incidents

• May be dispatched directly or through contracted service provider


• Push or otherwise clear disabled vehicles from roadway

• Provide re-fuelling, minor maintenance, first aid kits, etc.

Ministry of the Environment • Act as central command authority for dangerous goods spills

Media Outlets • Provide traveller information

Transportation Agencies • Provide overall coordination of the incident

• Manage incident traffic impacts, such as closures, congestion

ATMS • Provide detection monitoring, dispatch, coordination and informationdissemination services to the central command authority and other emergencyservice agencies

Table 6 – Roles of Emergency Response and Related Agencies



duration of the incident, the amount of debris ordangerous goods spilled on the roadway, etc. Thisinformation may be organized into an incidentseverity level matrix that ranks degree of severity foran incident. An example of a simple incident severitylevel matrix is shown in Table 7, which illustrates thetype of data that is critical in determiningappropriate response levels.

Central Command Authority to CoordinateResponse Activities

To accurately assess the severity of an incident, thecritical data components must be communicatedback to a central point of command. The creation ofthis “central command authority” provides the

necessary structure to comprehensively assessthese incident data components, coordinate thenecessary emergency service and related agencies,and effectively manage the incident.

Most incident response efforts are coordinated on-scene by a central command authority. For example,a car fire incident would be commanded on-sceneby fire services with the assistance of police andtowing services. This type of centralized on-sitecommand can minimize the degree of duplication ofservices on-site, and the number of personalconflicts regarding roles and management of anincident. In so doing, the overall duration of an eventcan be shortened. By maintaining contact with anoff-site TOC, centralized command can best monitoron-site activities, devise traffic control and diversionstrategies, provide dispatch services, and coordinatethe tasks of the involved emergency service

Source: Salt Lake City Incident Level Example.

Table 7 – Example Incident Severity Level Matrix

Incident Level Criteria (an incident which includes one or more of the following)

• No injuries• Blocking part or all of one lane of travel• Disabled vehicles on the shoulder with occupants• Minor collisions moved off the roadway

• Minor injuries• Requires emergency personnel to respond• Blocking more than one lane of travel• Expected to last more than 10 minutes

• Serious injuries• Involves several vehicles• Vehicles or debris blocking multiple lanes, keeping one lane open• Minor dangeros goods spill• Expected to last more than 30 minutes

• Multiple fatalities• Serious dangerous goods spill or cleanup• Closure of the highway• Structural or other damage to the roadway requiring immediate response• Expected to last more than one hour

1

4

3

2



agencies. Maintaining contact with TOCs and othersupporting services can be facilitated through theuse of a shared-use mobile command-post vehiclewith on-board systems to simplify communication.

Determining the Correct Response Level

Once the incident has been assessed by the centralcommand authority, a number of questions must beanswered. Who needs the information? Whatinformation do they need? How are the informationbest delivered? The degree of severity of an incident,and whether dangerous goods are involved, willdetermine the response level to an incident. Table 8illustrates a simplified emergency agency responsematrix. By visually representing the responserequirements in this way, the central commandauthority can quickly determine the appropriateprocess and responsibilities.

6.3.3 The Role of ATMS in IncidentManagement Plans

The duration of an incident is comprised of several“stages”. These stages include the incident-to-detection time, the detection-to-response time, theresponse-to-clearance time, and the recovery time(i.e., the time to restore normal operating conditions).ATMS-supported incident management plans aredesigned to reduce the duration of each of theseincident stages.

It is very important to have comprehensivecoordination and advance planning with emergencyservices. The response capabilities of emergencyservice agencies can be enhanced by the followingATMS features:

Table 8 – Example Emergency Agency Response Matrix

Response Agency

Severity Levels

Low Traffic Impact High Traffic Impact

No DangerousGoods

(Lowest)

Low-levelDangerous Goods

No DangerousGoods

High-levelDangerous Goods

(Highest)

MTO (including towing) X X X X

Police Services (OPP/Local) X X X X

Fire Services X X X

Ambulance X X

Municipalities X X X

Media Outlets X X

Ministry of the Environment X



Incident-to-Detection Stage

The collection and storage of historical ATMS dataprovides valuable information about the “normal”conditions, and reasonable levels of variation intraffic conditions. A clear understanding of this datafacilitates automated incident detection routines bydefining what conditions fall outside of “normal”conditions.

Active monitoring of detection data, includingoperating incident detection algorithms and reportsby cellular telephone users, ensures rapid detectionof incidents.

Detection-to-Response Stage

TOCs are suited to compile and assess incidentinformation derived from a number of inputs, such asCCTV, multiple driver reports, automatic detectors,patrol information, etc. The TOC can ensure timelyand accurate analysis of incident information, aswell as assist in assessing the necessary level ofemergency service deployment and in preventingconfusion with respect to information on secondaryincidents.

Upon detection and analysis, the critical incidentinformation is communicated to the appropriateemergency services by the TOC operators. Often,mobile data terminals located on-board emergencyservice vehicles are used to receive data transmittedfrom the TOC or from emergency service agencydispatchers to improve the speed and accuracy ofcommunication. Having received only accurate andpertinent information, the emergency serviceproviders can make an accurate assessment ofappropriate response levels (e.g., number ofvehicles, types of equipment, etc.).

ATMS services can reduce emergency servicestravel time to the incident scene in a number ofways. Accurate traffic condition information can berelayed to the emergency response vehicle, therebyallowing improved route selection. Route and local

modifications to traffic signal control that givepriority to emergency response vehicles can betriggered by on-board transponders, once detectedby intersection-specific, wayside, or GPS systems.

During this stage, TOC operators can begin toimplement diversion strategies to mitigate theeffects of an incident. Through the use of localdiversion plans, DMSs and other modes of travellerinformation dissemination, and modifications totraffic control devices, TOCs can influence motoristroute selection to avoid the incident area over thecourse of its duration. This provides relief tocongestion and the traffic control measuresnecessary at the incident site to manage traffic.

In the event of an incident involving a vehiclecarrying dangerous goods, automated notificationservices can provide an immediate description of thedangerous goods to the appropriate emergencyresponders. There are various electronic systemsthat could assist in the identification of vehiclescarrying dangerous goods, including automaticvehicle identification (AVI) and automatic vehiclelocation (AVL) technologies. These services canfacilitate an appropriate level of response in thiscircumstance. Vehicle management systems canalso provide accurate information regarding thenumber and location of available emergencyvehicles. This would allow the appropriateemergency service agency dispatcher to send thefirst available vehicle to the incident site.

Response-to-Clearance Stage

By working with the centralized on-site commandauthority, TOC operators can assist in coordinatingresources, monitoring the scene, and updatingtraveller information. For secondary incidents, TOCoperators can provide detection, dispatch and co-ordination support services to the central commandauthority. Managing the traffic queue also entailswatching for secondary collisions. Monitoring forblocking disabled vehicles and sending assistance to



them can also support site management and reduceoverall incident duration. If the anticipated durationof an incident is revised, TOC operators can workwith the centralized command to revise the diversionroute or incident response plan.

If closures or alternate routes are required, TOCs canplay a role in identifying the optimal route, informingaffected responders (and the media) and alteringtraffic control devices (e.g., traffic signals, rampmeters, etc.) in order to manage traffic at theincident site and on the alternate routes aseffectively as possible.

Clearance entails more than getting disabledvehicles and debris off the roadway. It also meansusing TOC capabilities to clear the queue as quicklyas possible once the roadway is clear. It can alsomean assisting with actual cleanup and clearance.TOC operators can evaluate an incident and sendthe appropriate equipment for clearance as early aspossible.

Collision Reporting Centres (CRCs) are designatedlocations off of the transportation network whereminor collisions can be dealt with. In the event ofnon-injury collisions, where the vehicle is still mobileand safe to drive, involved parties may proceed to aCRC to exchange details and file a collision report.The use of a CRC reduces the length of time anincident is present on the roadway. This reduces therisk of secondary collisions as well as the impact ofcollisions and the associated non-recurrentcongestion experienced (especially in areas wherethere are no shoulders) by reducing rubberneckingand ensuring that the lanes return to their fullcapacity as quickly as possible.

The duration of major incidents involving fatalitiestypically extends to several hours in order to facilitatepolice investigations. ATMS operating agenciesshould work closely with the police and otheremergency services to develop strategies andprocedures for minimizing the investigation andclearance times under these circumstances.

Recovery Stage (Restoration of Normal OperatingConditions)

The centralized command authority can work withTOCs to safely manage the return to normaloperating conditions. Once central command hasindicated it is safe to do so, the TOC operators canrevise traffic control strategies, update travellerinformation, etc. Motorist information shouldcontinue to be disseminated after an incident iscleared and until traffic flow returns to normalconditions.

The collection of data on response times andprocedures, traffic conditions, and actions takenduring the event can help in revising and improvingpre-determined incident response plans. This mayalso result in recommendations for operationalimprovements along diversion routes.

6.3.4 ATMS Roles in DisasterCommand and Control

While ATMS-supported incident managementconcepts and systems can be applied to emergencymanagement, they can also be considered forapplication in addressing large-scale disasters andevents concerning national security. These eventstypically occur at random with little or no advancewarning, and can induce extreme traffic demandunder an evacuation condition caused by severeweather or other major catastrophe.



Response to large-scale terrorist acts requires all ofthe resources and strategies of traffic incidentmanagement across a large geographic area, whereinter-agency coordination, communication andcooperation are critical. The TOC can serve as adisaster command and control centre, with TOCpersonnel and systems supporting the coordinationand communication efforts, or providing support tothe responsible emergency operations centre. Theavailability of adequate centre-to-centrecommunications is critical in this role to provide forthe real-time exchange of data and video informationbetween the TOC and related agencies or betweenthe TOC and the emergency operations centre.

6.3.5 Coordination of Planned Special Events

Planned special events are an activity or series ofactivities that take place in known locations withscheduled times of occurrence and associatedoperating characteristics that are expected to havesignificant traffic impacts. These events mayincrease or disrupt the normal flow of traffic onfreeway/arterial corridors serving the event venuelocation.

With the primary goals of ATMS being improvementin traffic flow management and reduction incongestion/delay, the various ATMS strategiesdiscussed under Section 3.6, namely, incidentmanagement, congestion management, corridor/network management and travel demandmanagement, can assist the responsible agencies inmanaging the special events. Depending on thetype of event, the location of the event and theduration of the event, the situation room within theTOC can serve as the central “command post” orback-up support for the coordination of the specialevent in conjunction with police services, organizersof the event, etc. Due to the extent of the likelyimpact of some of the planned large scale events,

the development of corresponding eventmanagement plans, similar to the incidentmanagement plan, is recommended for bettercoordination and efficiency.

Ontario ExperienceMTO has been advocating the development of amajor incident response team program as part of itsCOMPASS operations. Teams would be comprisedof all emergency services, municipalities, and otherrelevant Ministries. MTO traffic operationsrepresentatives would be available on-site as part ofa multi-disciplinary incident management team, andwould maintain coordination with the TOC. Theseproposals were initially viewed by police and fireservices as an intrusion into their respective domainsof responsibility. However, there is an increasingsense among various parties that the participation ofa qualified representative to address local and area-wide traffic issues would help the police and fireservices to focus on responding to and clearing theincident.

Regional traffic control systems, such as MTO’sCOMPASS system operating on Highway 401 andthe Queen Elizabeth Way, and the City of Toronto’sRESCU system operating on the GardinerExpressway, Lake Shore Boulevard, and the DonValley Parkway, provide assistance to emergencyvehicle management as part of their incidentmanagement responsibilities.

The COMPASS Traffic Operations Centre inDownsview served as the command post during thevisit of Pope John Paul II to Toronto for World YouthDays in July 2002 and the Rolling Stones TorontoSARS Concert in July 2005.



6.4 Maintenance

The ATMS, as a complex real-time computer-basedsystem, requires a full maintenance programthroughout the life of the system in order to protectthe significant investment made and to ensure that itremains fully operational.

Consideration should be made for a maintenanceand system support contract as part of theimplementation of the ATMS. This maintenancecontract should clearly state a defects liability or“warranty” period, in the range of 12 to 24 months.During this period, the contractor is responsible forrepairing or replacing any equipment or softwarefailures that may emerge subsequent to relinquishingthe system to the owner. In addition, provisions forroutine corrective and preventive maintenance andplanned upgrades, as well as emergency repairs thatare not the responsibility of the main contractor,should be incorporated. Such events may includeminor expansions to the field infrastructure, damageto the system caused by third parties (e.g., poleknockdowns, cable cuts, vandalism), systemconfiguration, database management activities, etc.

The maintenance requirements should be developedto cover all elements of the system, including:

• Field devices and electronic equipment• Communications system• Central software and database• Computer hardware and peripherals• TOC facilities.

The contract should establish appropriate responsetimes for various types of failures, both during andoutside of normal working hours. A schedule of ratesand prices for various products and services will berequired, with penalties for non-performance. Due totheir high exposure, DMSs and LCSs should have ashorter response time than other subsystems tomaintain safe operation and a high confidence levelamong motorists.

One of the functional issues to be resolved duringthe specification writing process will be therequirement for maintenance access to the DMSs.Several options may be considered, including frontor rear access via a catwalk along the gantrystructure, or walk-in type sign enclosures. Thepreferred solution will be dependent upon specificagency safety requirements, availability of safemaintenance vehicle pull-off sites, and the desire tominimize the frequency and duration of lane closuresfor maintenance purposes. These solutions must beweighed against their installation costs. It isrecommended that the contract includesmaintenance provisions for an initial period of threeor more years, with an optional extension by mutualagreement. At the expiry of that contract, it may benecessary to re-tender the maintenance services,possibly combining ATMS requirements with othersimilar agency systems.

Typical annual maintenance costs for similarsystems are in the range of 5% of the installedcapital base. In addition to annual maintenancecosts, the life of the system components must beincorporated and the costs of upgrades andreplacements included. In any economic analysis,the civil components should be assumed to last for aperiod of 25 years, the communicationsinfrastructure for 15 years, and the electronic andsoftware components for 10 years.

Warranties for the ATMS system should beintegrated into the original ATMS implementationcontract to avoid high costs for equipmentreplacement and system support due to systemfailures

6.5 Legal Issues

Various legal issues pertaining to ATMSs need to beaddressed in order to protect the travelling public,system operators and private industry. Newtechnologies and ways of doing business often raisequestions about how groups will be protected and



held responsible under existing law. The same issuescan be seen in almost any segment of society wherea significant change has taken place. Examples thatare comparable to ITS include telecommunicationsand information technology. This discussion focuseson four categories of legal issues:

• Liability• Privacy• Intellectual Property• Procurement Practices.

6.5.1 Liability

A significant risk to both government agencies andcommercial vendors is legal liability. Any newtechnology or process raises questions pertaining tohow the user can expect to be protected, and who isat fault if the system does not perform as expected.These systems present new sources of exposure toliability, and government agencies need to protectthemselves. There is potential to legislate awayliability, such as that in place for the protection ofpublic servants in the course of doing their work.However, there is a tendency not to pursue thisapproach at the risk of public individuals losing theirrights. Indemnity can be defined in specificagreements, however, there still remains the issue ofgeneral liability. There is also the potential forexposure to liability through partnerships, andorganizations need to protect themselves from suchliabilities in the event of a system failure.

6.5.2 Privacy

Another barrier to widespread adoption of certaintechnologies is privacy. Travellers may be concernedthat traffic monitoring efforts may eventually lead to“Big Brother” tracking an individual’s dailymovements. The primary approach to address thisissue has been to develop methods for assuringprivacy through anonymity. Furthermore, publicagencies have been reinforcing the understandingthat travelling on public roads is not a private activity.

ITS America is proposing to use a protocol calledPrivacy Enhancement Protocol (PEP) forguaranteeing privacy by assuring anonymity ofindividuals while still allowing distinction betweenindividual vehicles.

Requirements of legislation at the provincial and/orlocal level that protect the privacy of individuals andaccess to information need to be reviewed beforeinitiating traffic monitoring-related programs toensure policies and procedures are put in place toprotect the privacy of private citizens, and thatinformation collected is properly handled. Specificareas of concern include:

• Tracking of transponder-equipped vehicles fortravel time monitoring;

• Identification and processing of violationenforcement by outside vendors; and

• Use and distribution of CCTV video recordings.

With respect to CCTV monitoring, ATMS operatorsroutinely record video and distribute live video feedsto the media. Policies and procedures need to beestablished to control the non-traffic managementrelated uses of the video. Specific measures caninclude blocking detailed incident images frommedia distribution, and avoiding zooming the camerato the extent that license plate or individuals arerecognizable. As an exception to the latter example,some ATMS agencies exercise the authority to zoomin and record activity in the roadway corridor whencriminal activity is suspected.

6.5.3 Intellectual Property

Many ATMS projects involve a commercial vendordeveloping a customized software and/ortelecommunications package for a governmentagency. In some cases, the initiative may be apublic-private partnership, while in others it may be aconventional customer-vendor arrangement. The



development of technologies and processes and thecollection of data raise intellectual property andownership issues which can be challenging toaddress. Vendors are accustomed to retaining therights to whatever they develop, while a governmentagency may (often by law) expect to retain the rightsto anything developed using tax-payer funding.While some governments have faced these issuesbefore, typically transportation agencies have littleexperience in this area. Furthermore, the rapidlyevolving communications and informationtechnology industries make the issue far morecomplicated.

Even in cases where a practical and mutuallyacceptable agreement on intellectual property canbe reached, existing legislation may block such adeal. Existing provincial government policiesstipulate that if the province pays for development,they own the intellectual property. There is littleflexibility to accommodate joint ownership. Existinglaws and procurement policies were not developedwith the needs and circumstances of ATMS andother information technology applications in mind.The process of modifying laws to both protect thepublic, and facilitate and encourage ATMS projectswith intellectual property issues, can be extremelytime-consuming.

6.5.4 Procurement

Public sector departments active in ATMS aretypically limited in their flexibility with respect toprocurement policies and mechanisms. Agenciesare typically restricted to public tender and requestfor quotation (RFQ)/request for proposal (RFP)processes for procurement. For transport authorities,these processes are typically oriented towards hardengineering for infrastructure development and maynot provide the flexibility for innovative multi-agencyATMS applications. Agencies dealing with ATMS

need some degree of flexibility and autonomy topursue these innovative solutions, while stillmaintaining and demonstrating open and fairprocurement practices.


At the City of Toronto, operators use the CCTVcameras to obtain close up views of an incident orcollision. The video images captured are archived.Images that show the person or license plate of thevehicle involved are not released to the media orexternal agencies. This also helps with any litigationplaced against the camera-operating agency forrevealing personal information.

The experience with legal issues to date for OntarioATMS programs yields the following observations:

• Legislation is required to provide the flexibility forthe public sector to readily enter into innovativepartnerships with the private sector for ATMSdevelopment and deployment.

• It is important to have well defined contractualterms and conditions and operating procedurespertaining to the use and distribution ofinformation collected by an ATMS.

• A comprehensive public information processneeds to be established to address inquiries fromthe public pertaining to privacy and enforcement.



7. Evaluation of ATMS

7.1 Overview of Evaluation

The design, implementation and operations of anyATMS will require the commitment of variousresources. Such resources include staff time,technical expertise, funding, etc., all of whichrepresent an investment by the agency in ATMS. Inorder to determine the value of the investment to theagency and the general public, the relative prioritythe investment in ATMS holds with respect to otherdemands on public funding, and the components ortypes of ATMS that can be justified, an evaluation ofthe proposed system and its alternatives should beundertaken. This evaluation will provide informationthat can be used to formulate the most cost-effective ATMS, as well as help to gain support fromsenior management, decision makers and thegeneral public.

Various typical evaluation techniques available forATMS alternatives are discussed below.

7.1.1 Benefit-Cost Analysis

This technique compares the economiceffectiveness of ATMS alternatives on the basis oftotal transportation costs, including capital cost,operating cost, maintenance cost, vehicle delays,travel time cost, etc. The associated cost criteriainclude:

• Benefit-cost ratio• Rate of return• Net present value• Equivalent uniform annual cost.

It is generally recognized that ATMS applications areeffective in facilitating better utilization of existingtransportation infrastructure and can generate suchbenefits as relieving congestion, increasing trafficthroughput, and improving traffic safety and air

quality. However, the methodologies and data toquantify the effectiveness and benefits of suchapplications are not well documented, and themajority of benefits may not be realized under anindividual project, but arise from the integration ofprojects. For example, the provision of monitoringdevices or communications infrastructure maybenefit a number of ATMS applications planned forimplementation over a number of years, but may bedifficult to justify under the initial project. Benefit-cost analysis may have to be addressed from anintegrated or overall system perspective.

7.1.2 Performance Rating Tables

This technique simply rates the performance orusefulness of alternative systems with a low,medium or high score. Typically, the scores onlyreflect the perceived or anticipated performance ofthe components or alternative systems.

7.1.3 Linear Scoring Function Tables

Similar to the performance rating table, thistechnique rates and compares alternatives. Eachalternative is assessed with an initial score, from 1(lowest) to 10 (highest) against each evaluationfactor. This score is then multiplied by the relativeweight given to that factor. The best alternative isthe one that accumulates the most points.

7.1.4 Incremental Analysis Technique

The above-mentioned techniques are based on theassumption that although the life cycle cost of anATMS can be measured in monetary terms, theeffectiveness of these costs towards the system’sgoals and objectives is best described in qualitativeterms. A refinement to the evaluation technique is todivide the implementation of the system into stages



and develop incremental benefit-cost ratios orratings for each of the stages. The incrementalanalysis technique is very useful in evaluatingcomplex and large-scale transportation investments.

7.1.5 Discussion

The selection of an evaluation technique should bebased on data availability, the availability ofresources, and the level of detail required fordecision making. The evaluation must also rely onjudgement and local experience to generate themost appropriate assumptions for the analysis.Sensitivity analysis can also be employed in the finalanalysis to reduce the effects of inherentuncertainties, including the rapid change oftechnology, the estimated benefits from simulationmodels, etc.

7.2 Measures of Effectiveness

Advanced traffic management systems are alwaysdesigned and implemented to meet the specificgoals and objectives of the area. In order to evaluatethe degree of success of the ATMS in meeting thesegoals and objectives, a set of Measures ofEffectiveness (MOEs) must be developed. TheseMOEs are very useful in the determination of whensystem expansion and possible systemenhancements are required.

The MOEs must be defined in a manner so that theoperation of the system can be quantitativelydescribed and/or estimated. They should also bespecified in an appropriate level of detail so thatdata collection and analysis are possible. TheMinistry of Transportation Ontario has developed aset of typical MOEs for ATMS evaluation which aresummarized in Table 9.

The Ministry of Transportation Ontario’s Ontario ITSStrategies Framework Study and Five YearCOMPASS Implementation Plan incorporates anevaluation of the potential projects for thegeographic expansion of COMPASS. A comparativeevaluation of the candidate segments has beenconducted using the following criteria:

• Cost – based on the estimated present value ofcapital costs only, as operation and maintenancecosts are usually estimated based on apercentage of the capital costs;

• Congestion and Environmental Priority – based onthe delay savings benefits, which are alsorepresentative of fuel savings and reducedcollisions, as well as environmental benefits fromreduced greenhouse gases;

• Safety Priority – quantified in terms of reduction insecondary collisions;

• Benefit-Cost Ratio – based on benefit and costestimations;

• Length – based on the length of the proposedsections, since the longer the length, the greaterthe COMPASS coverage and resultant area-widenetwork management improvements;

• Proximity to Existing COMPASS Projects – basedon spatial proximity of the proposed COMPASSprojects with existing COMPASS systems. Thisreflects the potential cost savings associated withmaking use of existing operation centres andbetter network management, data sharing, andcoordination among various components; and

• Special Situations – used to factor in a number ofdifferent characteristics that are importantconsiderations for expansion, such as existingprovision, planned construction activities, politicalreasons and strategic network links.



7.3 Evaluation and OngoingBench-Marking

For each ATMS, the Measures of Effectiveness(MOEs) are not only important in determining thesuccess of the system deployment, but also for theongoing evaluation and bench-marking. As such,resources and funding must be planned to undertakedata collection and an evaluation program over time.

In addition to the monitoring of the MOEs, there arealso other factors to be considered and evaluated forthe system expansion and/or migration. Thesefactors are discussed in the following sections.

Table 9 – Typical Measures of Effectiveness (MOEs) for ATMS

Objectives Measures of Effectiveness (MOEs)

Increase corridor traffic throughout• Monthly average daily traffic (veh/day)• Highest hourly volume per lane (veh/hr/lane)

Increase average travel speed• Monthly average peak period speed (km/h) for 08:00 to 09:00 and for 17:00 to 18:00

Reduce vehicle delays• Total monthly vehicle-hours of delay (veh-hours)• Time when travel speed is less than 70 km/h (minutes)

Decrease average travel time• Average travel time at 08:00 and at 17:00 for a specific roadway section (minutes)

Increase utilization and effectiveness of DMS • Number of non-default messages displayed per sign per day

Reduce number of collisions • Total number of confirmed incidents

Improve incident detection system• Percentage of incidents detected by system• Percentage of incidents detected manually• Percentage of false alarms

Reduce incident duration

• Total duration of incident (minutes)• Average duration of incident (minutes)• Incident detection time (minutes)• Response time to incident (minutes)• Incident clearance time (minutes)

Increase field equipment utilization• Percentage of VDS controller-hour availability• Percentage of DMS controller-hour availability

Reduce secondary incidents • Number of secondary incidents

Reduce vehicular delay due to incident reduction anddelay reduction

• Average delay (veh-hr)

Improve quality of traffic flow• Travel time index• Averaged speed (km/h)• Acceleration/deceleration ratio

Improve driver response (diversion) to DMS messages• User perception to the sign• Message accuracy of the sign



7.3.1 Quality of Service Evaluation

The quality of service should be measured, not justby the number of effectual services delivered to thepublic, but also in relation to the cost of deliveringthese services. There are no fixed rules andpractices for determining the final correctcombination of actions to be executed, however,some general guidelines should be considered.

Changes to an Existing System VersusAcquiring a New System

Changes to an existing system to achieve newfunctions can become more and more difficult as asystem ages, due to a lack of original designinformation or a legacy platform. Planning for thenext change and any subsequent changes istherefore important when deciding whether or not toproceed with a current change. An assessment mustbe made to determine the cost over the useful life ofthe system versus acquiring a new system.

Operational Versus Maintenance Cost

When considering keeping the existing systemversus acquiring a new system, one must includethe operational as well as the maintenance cost ofboth scenarios. Usually, the old system in operationhas a high maintenance cost because of theassociated legacy equipment. Additionally, animprovement in operation can usually be associatedwith a new system. Therefore, it is important thatthese costs are evaluated against the initial highcapital cost for the new system.

Quality of Services to the Public

Another criterion for determining the final correctcombination of actions is the actual level of serviceprovided to the public. There are usually measuresfor calculating benefits to the public. For example,average hours for motorists stuck in trafficcongestion can be associated with a total cost tomotorists for loss of time.

Parameters like the aforementioned criteria can beemployed wherever possible to derive an evaluationstrategy.

7.3.2 Communications System

The life of a communications system is limited. Theagency should regularly evaluate the performance ofthe communications system to ensure it meetsrequirements. The evaluation should include thefollowing parameters:

• Performance• Maintenance costs• Ability to meet new requirements.

The decision to replace the communications systemshould be made prior to the system failing, since thecommunications system is essential for theoperation of the system, and the design and upgraderequires significant time.

Performance

As the equipment ages, components will begin todegrade or fail. Ongoing maintenance activities canrepair the failed components, providing a level ofperformance equal to the original system operation.As the equipment reaches its design life, however,the ability to maintain the same performance levelwill be reduced. To ensure that the system maintainsthe desired performance, the following majorcomponents should be evaluated on an ongoingbasis. Experience shows that it will be useful to keeptrack of performance by recording and analyzing thecomponent, subsystem and system reliability andavailability data, including mean time betweenfailures (MTBF) and mean time to repair (MTTR).

Cable TestingIf the agency owns the cable plant, yearly testingshould be conducted to determine if degradation inthe cable plant is occurring. The results of theprevious year’s tests should be compared to the



most recent to determine if any degradation hasoccurred. A benchmark should be set to determinethe level of performance at which the cable plantshould be replaced.

Cable would typically be replaced on a system-widebasis although, if only a specific section has beendamaged, it could be designated for replacement.

The nature of the tests to be conducted will dependon the communications medium but should include:

• Sweep tests conducted on the coaxial cable;

• Optical time domain reflectometer (OTDR) andattenuation tests conducted on fibre optic cable;and

• Frequency response and attenuation testsconducted on twisted wire pair cable.

Data System TestingData transmission failures are typically logged by thecentral software, and no special testing is requiredto monitor channel performance. For ongoingmaintenance, personnel respond to failures in thenetwork and repair the equipment based on detaileddiagnostic procedures. The need to replace thecommunications system should be based on anyinability to resolve recurring failures and lowavailability rates.

Video System TestingThe operation of the video transmission system isbased upon observation of the video performance bythe operators. Distortion or noise in the signal isreported to maintenance personnel for correction.The need to replace the system should be based onany inability to resolve recurring failures or lowavailability rates.

Maintenance Costs

The second factor in determining communicationsnetwork replacement is the maintenance costsassociated with the system. Maintenance costsconsist of:

• Staff Time Associated With Correcting Faults – Asthe network degrades, the staff time needed totroubleshoot and repair equipment increases.

• Spare Parts Replacement – The requirement forspare parts increases as the failure rate increases.As the system ages, the ability to source spareparts becomes more difficult, with associatedhigher costs. In the traffic control industry,communications systems are typically based onproprietary equipment resulting in only one vendorbeing able to supply and maintain the equipment.An example of this is the RF modems supplied forthe coaxial cable systems.

• Leased Costs – The cost of certain leasedservices, such as analogue circuits, has increasedsince the telephone company is no longerinterested in supplying this type of service. Otherservice offerings may be more cost-effective.

The decision to replace the system requires ananalysis of the cost to maintain versus the capitalcost of replacement.

Ability to Meet New Requirements

The third factor in determining equipmentreplacement is the ability of the existing system tosupport expansion requirements and new featuresdesired for system operation. As ITS systems mature,new features and equipment are added to thefunctionality of the system, which must be supportedby the communications system. The upgradeevaluation of the communications system mustaddress the following:



• Expansion Capability – The communicationssystem should be evaluated to determine thespare capacity of the system and the ability tomeet future requirements.

• Ability to Support New Subsystems – These newsubsystems will increase the number of channelsand loading on the communications system. Forregional traffic control systems, this could includeramp metering, queue warning and toll tagreaders. For surface street control systems, thiscould include CCTV and DMSs.

• Ability to Support New Protocols (i.e., NTCIP).

• Ability to Support Different CommunicationsInterfaces (e.g., Ethernet) – The older systems donot typically have the ability to provide the newinterfaces and data rates necessary to support thenew equipment controllers and their associatedinterfaces.

In summary, the communications systemperformance should be analyzed in an ongoingmanner to ensure that the objectives of the ATMSsystem are maintained. This analysis should includecurrent performance, maintenance costs and theability to meet new requirements.

8. Integration withOther Systems

Intelligent Transportation Systems (ITS) is defined asthe application of advanced and emergingtechnologies (computers, sensors, control,communications and electronic devices) intransportation to save lives, time, money, energy andthe environment.6 With this definition, ITSencompasses a broad range of applications,covering all modes of road-based transportation,including private automobiles, commercial vehicles,public transportation, bicycles, pedestrians, etc. Theterm “ITS” also includes consideration of the vehicle,the infrastructure, the driver and the user of thetransportation system.

With such a broad range of applications of leading-edge technology, an extensive array of opportunitiesfor integration presents itself, namely, integrationbetween systems and across modes andjurisdictions that allows sharing of information andjoint use of infrastructure for multiple purposes. Thisintegration of technologies and systems not onlyallows for a more cost-effective approach to theimplementation and operation of ITS, butsignificantly increases the benefits that can beachieved through the use of technology to bettermanage transportation networks.

The integration of systems requires a framework orarchitecture that identifies all of the potentialopportunities and how this can be achieved. The ITSArchitecture for Canada was developed for thispurpose and to serve as a framework to assistjurisdictions in the planning, design andimplementation of their ITS systems.

6 ITS Canada website. http://www.itscanada.ca/english/aboutits.htm



The ITS Architecture for Canada is a product of the1999 Federal Government ITS Plan for Canadaentitled “En Route to Intelligent Mobility” (TransportCanada, 1999). In this document, the architecture isdescribed as the communication and informationbackbone that unites key ITS initiatives enablingthem to communicate with each other, and aframework that identifies the requirements forsupporting integration of functions and inter-operability across specific applications, modes andjurisdictions. As a jurisdiction develops its ITSprogram, the intent is to use this framework as a toolin the planning, design and implementation of theirITS systems. This tool will help the localtransportation authority to think of the “big picture”,the functions each application performs, and howthese applications can work together with existingsystems to meet both current and future needs.

In this section, various user services of the ITSArchitecture for Canada are discussed and potentialopportunities for integration with ATMS applicationsidentified. For more information on the ITSArchitecture for Canada and the related userservices, the reader is referred to Transport Canada’swebsite (www.its-sti.gc.ca/Architecture/).

8.1 ATMS Integration with TravellerInformation Services (ATIS)

Traveller information consists of services designed touse advanced systems and technologies to manageinformation and help travellers decide when to travel,the mode and route to take, as well as provideassistance in arranging ridesharing and providinginformation for a variety of traveller-related servicesand facilities. It integrates information from variousmodes and sources for decision-making purposesand consists of:

• Real-time Traveller Information Services – Providetravellers with information prior to their departureand en-route through a variety of personal and in-

vehicle devices to assist them in making modechoices, travel time estimates, and routedecisions.

• Route Guidance and Navigation Services – Providetravellers with instructions on turns and othermanoeuvres to reach selected destinations. In asimple form, a user would input a destination andbe provided with a fixed recommended route. In amore dynamic mode, the user would receiveinstructions on route selection as he/she proceedsto the destination. This could include informationthat takes into account traffic conditions.

• Ride-Matching and Reservation Services – Expandthe market for carpools and vanpools by providingreal-time ride-matching information along withreservations and vehicle assignments.

• Traveller Services and Reservations – Provide thetraveller with access to “yellow pages” typeinformation regarding a variety of travel-relatedservices and facilities. The information will beaccessible to the traveller in the home or office tosupport pre-trip planning and while en-routethrough in-vehicle devices or public facilities, suchas public transit terminals or highway rest stops.

The integration of ATMS and traveller information isfundamental to the success of both of these ITSapplications. ATMS utilizes vehicle sensors tomonitor traffic conditions, and CCTV cameras formonitoring purposes and verification of incidents.Sharing of traffic and incident information provides asource of real-time data for traveller informationpurposes, thereby improving the ability of ATIS todisseminate accurate and reliable information on atimely basis. The broad distribution of thisinformation through traveller information devices alsoprovides benefits to the ATMS applications byproviding advanced warning of unusual trafficconditions, encouraging traffic to divert to otherroutes, balancing traffic between corridors, andultimately providing the ability to better manage theoverall transportation network.



8.2 ATMS Integration with AdvancedRoad Weather InformationServices (ARWIS)

Traffic management services within the ITSArchitecture for Canada consists of a broad range ofuser services designed to use advanced systemsand technologies to improve the efficiency andoperation of the existing surface transportationinfrastructure, as well as create safer conditions fortravellers. This user service is the focus of thismanual and the majority of traffic managementapplications are well documented within this book.

Advanced road weather information systems(ARWIS) monitor current road and weatherconditions using a combination of weather serviceinformation and data collected from environmentalsensors deployed on and about the roadway. Thecollected road weather information is monitored andanalyzed to detect and forecast environmentalhazards, such as icy road conditions, dense fog, andapproaching severe weather fronts. This informationallows road maintenance staff to respond to weatherconditions in a planned and pro-active manner. Thisincludes enabling road maintenance staff to makebetter informed decisions in the deployment ofresources and the selection of de-icing materials.

The integration of ARWIS and ATMS allows datasharing between these systems that can be used fora number of purposes including:

• Providing ATMS operators with information onsurface conditions, which in turn may be used toadjust traffic control strategies (e.g., signal timingplans), increase monitoring of select corridors forincident detection, etc.; and

• Providing road maintenance staff with access toreal-time traffic information and congestion levels,as input to snow plow operation and routeoptimization as part of their fleet managementsystems.

8.3 ATMS Integration with AdvancedPublic Transport Services (APTS)

Public transport services include urban, suburbanand rural transit in fixed route, route deviation anddemand-responsive modes operated by bus, heavyrail, light rail, commuter rail, van, carpool, or sharedride taxi. All forms of short distance transportationnot involving a single occupant automobile benefitfrom these services which include:

• Public Transport Management – Applies advancedvehicle electronic systems to various publictransportation modes, and uses the datagenerated by these systems to better manage theoperation and maintenance of the vehicles,planning and scheduling of routes and schedulingpersonnel in order to improve the level of servicesprovided to the customer. It includes vehicletracking, real-time schedule information, fleetmanagement, multi-modal connection protection,etc.

• En-route Transit Information – Provides travellerswith real-time transit and high-occupancy vehicleinformation allowing travel alternatives to bechosen once the traveller is en-route. This userservice integrates information from differenttransit modes, and presents it to travellers fordecision making.

• Demand Responsive Transit – Involves the use oftechnology to flexibly route transit vehicles fromtheir pre-established route to pick up or dischargepassengers in order to provide more convenientservice to customers.

• Public Travel Security – Supports innovativeapplications of technology to improve the securityof public transportation. Security concerns includeprotecting transit patrons and employees fromstreet crime, maintaining an environment of actualand perceived security, and developing innovativetechnical measures to respond to incidents.



The opportunities for integration between ATMS andAPTS applications are significant, and are primarilyrelated to the sharing of traffic and incidentinformation. Examples include:

• Provision of ATMS traffic congestion and incidentinformation to the transit fleet managementsystems. This information can be used to estimatebus arrival times for real-time passengerinformation systems, optimize routes for demandresponsive transit, and assist transit dispatchers inre-routing buses in the event of a major incident.

• Use of vehicle tracking information from the APTSto provide transit signal priority through the ATMS.This can be conducted for individual intersections,as well as for routes incorporating multiplesignalized intersections. It can also incorporatevariable levels of signal priority depending onwhether the transit vehicle is full/empty, ahead/behind schedule, etc., when it is interfaced withreal-time schedule information and automatedpassenger count systems.

• Use of buses as vehicle probes to monitor trafficconditions or as a method of detecting incidentsto supplement ATMS and its ability to monitorconditions on the arterial street network.Information can be obtained through driversupplied information (e.g., verbal reports, textmessages, etc.) or using vehicle locationtechnology (e.g., GPS).

• Sharing of video images from security cameras attransit stations and major transfer points tosupplement ATMS CCTV systems, and increasethe ability to verify incidents within thetransportation network.

8.4 ATMS Integration withElectronic Payment Services

The electronic payment user service allows travellersto pay for transportation services by electronicmeans. This includes such applications as electronictoll collection, electronic fare collection, electronicparking payment, and electronic payment servicesintegration. It may also serve broad non-transportation functions, and may be integrated withcredit and debit cards in banking and other financialtransactions.

Opportunities for integration between electronicpayment services and ATMS primarily relate to thejoint use of in-vehicle devices that allow electronicpayment equipped vehicles to be used as vehicleprobes to monitor traffic conditions. The transponderidentification number is used to track individualvehicles between reader locations as a measure oflink speeds and travel times. This however requiresthe cooperation of the owner of the transponder.

8.5 ATMS Integration withCommercial Vehicle Operations(CVO)

Commercial vehicle operations is concernedprimarily with freight movement and focuses onservices which improve private sector fleetmanagement, freight mobility, as well as streamlinegovernment/regulatory functions. This includes:

• Commercial Vehicle Electronic Clearance –Consists of both domestic and international borderelectronic clearances. Domestic electronicclearance allows commercial vehicles to continuepast inspection stations without stopping.International border clearance allows vehicles tobypass international border checkpoints withoutstopping, or at least with expedited checks. As avehicle approaches an inspection station orcheckpoint, vehicle-to-roadside communicationstake place that identify the vehicle and makeavailable to authorities the necessary data about



credentials, vehicle weight, safety status, cargo,and occupants. Enforcement personnel can thenselect potentially unsafe or non-compliant vehiclesfor inspection and allow safe and legal vehicles tobypass the inspection station/checkpoint.

• Automated Roadside Safety Inspection – Providesautomated inspection capabilities that checksafety requirements more quickly and accuratelyduring a safety inspection that is performed whena vehicle has been pulled off the highway at afixed or mobile inspection site. An example wouldbe a rolling dynamometer which checks brakeperformance.

• On-board Safety Monitoring – Provides the abilityto sense the safety status of a vehicle, cargo, andthe driver at mainline speeds. Driving time anddriver alertness would typically be the type ofconditions sensed for a driver. Warnings orindications of the safety status are provided to thedriver. This data would also be provided to thecarrier, and to enforcement authorities.

• Commercial Vehicle Administrative Process –Includes systems that allow the carriers to trackand monitor vehicle location and operations, andautomatically generate reports required topurchase commercial vehicle credentials. Thisincludes automated mileage and fuel reporting,electronic purchase of credentials, andinternational border electronic clearance.

• Intermodal Freight Management – Provides theability to monitor the location and status of freightin-transit and at freight terminals.

• Commercial Fleet Management – Provides real-time communications for vehicle location,dispatching and tracking between commercialvehicle drivers, dispatchers and intermodaltransportation providers, thereby providingdispatchers with real-time information on freightlocation and estimated time of arrivals, and

providing drivers with the ability to receive routinginformation en-route in response to congestion,incidents or changes in pick-up locations.Commercial fleet management includes themanagement of taxi fleets.

The opportunities for integration between CVO andATMS are similar to the opportunities discussedunder electronic payment with the joint use ofin-vehicle devices and vehicle location informationto enable the use of the commercial vehicles asvehicle probes to estimate link travel speedsand/or travel times as a method of measuringtraffic conditions, locating areas of congestion/incidents, etc.

8.6 ATMS Integration with EmergencyManagement Services

Emergency management includes services thatrelate directly to the detection, notification andresponse by emergency service agencies to trafficincidents. This includes:

• Emergency Notification and Personal Security –Provides the capability to automatically or for auser to manually initiate a distress signal forincidents like mechanical breakdown or non-injurycollisions. The signal would automatically includeinformation regarding the location, nature andseverity of the collision to an emergency serviceagency dispatcher and/or to hospital andemergency room personnel.

• Hazardous Materials (HAZMAT) Incident Response– Provides cargo-related information to emergencyresponse agencies at the scene of an incident.

• Disaster Response and Management –Coordinates disaster response strategies from avirtual control centre, and disseminatesinformation to agencies and individuals on trafficconditions, diversion routes, etc.



• Emergency Vehicle Management Service –Reduces the time from the receipt of notificationof an incident by an emergency service agencydispatcher, and the arrival of emergency responsevehicles on the scene. It includes emergencyvehicle fleet management, route guidance to theincident scene or a suitable hospital, and pre-emption of traffic signals on an emergencyresponse vehicle’s route to receive more greendisplay.

The opportunities for integration between ATMS andemergency management applications are similar tothose discussed under APTS, and are primarilyrelated to the sharing of traffic and incidentinformation. Examples include:

• Provision of ATMS traffic congestion and incidentinformation (including CCTV images) to theemergency response agency’s dispatcher andcomputer-aided dispatch system. Details of theincident could help the dispatcher to better assess

the incident, and establish the equipment andpersonnel to dispatch to the scene. The sharing ofreal-time traffic information with the emergencyfleet management system would allow the systemto select routes for the emergency responsevehicles based on shortest travel time usingcurrent traffic conditions.

• Use of vehicle tracking information from theemergency fleet management system to providetransit signal priority through the ATMS. This canbe conducted for individual intersections as wellas for routes incorporating multiple signalizedintersections.



Index

AAADT (Annual Average Daily Traffic), 3.2.1, 3.2.3,

Appendix A

Access Control, 2.3, 4.3.2, 6.2.3

Active Transponder, 4.1.8

Advanced Ramp Control Warning Signs, 4.3.1

AID (Automatic Incident Detection), 4.1.5, 4.6.2,Appendix A

Ambulance, 3.1.3, 4.1.7, 4.1.11, 5.4, 6.2.1, 6.3.2,Table 6, Table 8

APID (All Purpose Incident Detection), 4.1.5, Figure6, Table 4, Appendix A

APTS (Advanced Public Transport Services), 8.3,Appendix A

Arterial Advisory Signs, Table 2, 3.7.1

Arterial Master Systems, 4.2.2, 4.7.1

ARWIS (Advanced Road Weather InformationSystems/Services), 4.1.12, 8.2, Appendix A

Assisted Global Positioning System (AGPS), 4.1.8,Appendix A

ATC (Advanced Traffic Controller), 4.1.4, 4.7.1,Appendix A

ATIS (Advanced Traveller Information System/Services), 4.4.1, 4.5, 4.5.1, 4.5.4, 8.2,Appendix A

ATMS System Maintenance and Support, 6.2.1

Automated Notification Service, 6.3.3

Automated Roadside Safety Inspection, 8.5

Automatic Vehicle Identification (AVI) System, 2.1.2,4.1.8, 4.2.3, 5.4, 6.3.3, Appendix A

Automatic Vehicle Location (AVL) System, 2.1.2,4.1.8, 4.2.3, 6.3.3, Appendix A

Automated Voice Information System, 4.5.1

Autonomous Route Selection and Guidance, 4.5.2

AWS (Advance Warning Sign), 1.3

BBottleneck, 2.2, 5.1

Breakdown, 2.1.1, 3.1.3, 3.2.1, 3.3.2, 4.1.2, 4.3.2,5.4, 6.2.1

Breakdown Service, 6.2.1

Bridge/Tunnel Management, 5.1

Broadcast Traffic Reports, 6.2.1

CCall Box, 4.1, 4.1.7

Call Switching Equipment, 6.2.3

Camera Control Equipment, 6.2.3

Catastrophe Theory Approach, 4.1.5

CCR (Camera Control Receiver), 4.7.1, 4.7.2,Appendix A

CCTV (Closed Circuit Television), 1.3, 2.1.1, 3.1.3,3.6, 3.6.1, Table 2, 3.7.2, 4.1.5, 4.1.6, 4.2.3,4.5.1, 4.5.4, 4.6.2, 4.7.1, 4.7.2, 5.2.6, 6.2.1,6.3.3, 6.5.2, 7.3.2, Appendix A

CCTV Camera, 2.1.1, 3.7.2.1, 4.1.6, Figure 7,4.5.1, 4.7.1, 5.3, 5.4, 6.2.1, 6.2.2, 6.2.4,6.3.3, 6.5.2, 6.5.5, 8.1, 8.3

CCTV Image Resolution, 6.2.4

CCTV Image Size, 6.2.4

CCTV Images, 4.7.1, 5.4, 8.6

CCTV Monitor, 4.7.2, 6.2.2, 6.2.4

CCTV Specification, 4.1.6

CCTV System, 4.2.3, 8.3

Central Command Authority, Table 6, 6.3.2

Central Detection Processing, 4.1.5

Central Second-by-Second Control System, 4.2.2

Centralized On-site Command, 6.3.2, 6.3.3

Circuit Termination Cabinets, 6.2.2

Circulation/Access, 6.2.2

CO (Carbon Monoxide), 5.1.3, Appendix A

Coaxial Cable, 4.1.6, 4.7.2, Table 5, 7.3.2

Coaxial Network, 4.7.2

Collision Experience, 3.2.2

Collision Frequency, 3.1.3, 3.2.2, 3.3.3

Collision Rate, 3.1.3, 3.2.2, 3.3.3



Collision Report, 3.1.4, 6.3.3

Collision Severity, 3.3.3

Commercial Fleet Management, 8.5

Commercial Radio, 4.5.2

Commercial Vehicle Administrative Process, 8.5

Commercial Vehicle Electronic Clearance, 8.5

Communications Network, 2.2, 4.2.2, 4.2.3, 4.7.1,4.7.2, 6.3.1, 6.3.4, 7.3.2

Communications Systems, 1.3, 4, 4.2.2, 4.4.2, 4.7,6.4, 7.3.2

COMPASS, 1.3, 3.3.8, 3.6.3, 3.8, 4.1.5, Figure 7,4.1.7, 4.6.2, 4.6.5, 4.7.1, 4.7.2, 5.3, 6.2.2,6.2.4, 6.3.6, 7.2, Appendix B

Computer Aided Dispatch (CAD) System, 6.3.1,Appendix A

Computer System, 1.3, 2.2, 4, 4.1.5, 4.1.8, 4.3.1,4.6

Computer/Communications Room, 6.2.2, 6.2.3,6.2.4

Congestion Management, 3.3.4, Table 1, 3.6.1,3.6.2, 4.2.4, 6.3.5

Console, 6.2.2, 6.2.4

Contra Flow, 2.4

Control Room, 6.1, 6.2.2, 6.2.3, 6.2.4

Corridor Management, 1.3, Table 1, 3.6.3

CPU (Central Processing Unit), 6.2.2, Appendix A

CRC (Collisions Reporting Centre), 6.3.3, AppendixA

CVO (Commercial Vehicle Operations), 8.5,Appendix A

DDangerous Goods, 3.1.3, 6.2.1, 6.3.2, Table 6,

Table 7, Table 8, 6.3.3

Data Network, 4.7.2

Data Processor, 4.1.2

Data Radio, 4.7.2

Data Transmission, 4.2.2, 4.2.3, 4.6.2, 4.7.2, 7.3.2

DCS (Digital Communications Service), 4.7.1,Appendix A

Debris, 3.1.3, 4.1.9, Table 6, 6.3.2, Table 7

Demand Detector, 4.3.1

Demand Responsive Transit, 8.3

Detection-to-response, 3.1.3, 3.6.1, 6.3.3

Detection-to-response Time, 3.6.1, 6.3.3

Detection Zone, 2.1, 4.1.2, Table 3

DHV (Design Hour Volume), 3.1.2, 3.2.1, AppendixA

Disaster Response and Management, 8.6

Distributed Control System, 4.2.2, 4.7.1

Diversion Route, 3.1.3, 3.5, 3.5.1, 3.6.1, 3.6.3,6.3.3, 8.6

Diversion Strategies, 3.1.3, 3.6.3, 4.3.1, 4.6.2,6.3.2, 6.3.3

Diversionary (Messages), 4.2.4

Diverted Traffic, 3.3.2, 3.5.1, 4.3.1

DMS (Dynamic Message Sign), 2.5, 3.5.1, 3.6.3,Table 2, 3.7.2, 4.4.1, 4.5.3, 4.5.4, 4.6.2, 4.7.1,5.1.1, 5.2.1, 5.3, 5.4, 6.2.1, 6.2.2, 6.3.3, 6.4,Table 9, 7.3.2, Appendix A, Appendix B

Doppler Shift Detection, 4.1.2

DSRC (Dedicated Short-range Communications),4.5.2, 4.7.1, Appendix A

Dynamic Route Selection and Guidance, 4.5.2

EEDR (Emergency Detour Route), 5.4

Electronic Payment Services, 8.4

Electronic Road Pricing, 3.6.4

Electronics Unit, 4.1.1, 4.1.2

Embedded Detector, 2.1.1, 4.1.2

Emergency Agency Response Matrix, 6.3.2, Table 8

Emergency Incident Response, 6.2.1

Emergency Management Services, 4.1.9, 8.6

Emergency Notification and Personal Security, 8.6

Emergency Response Vehicle, 2.2, 3.1.3, 3.3.3,4.1.7, 4.2.3, 4.4.1, 6.3.3, 8.6

Emergency Service Agencies, 3.3.8, 6.2.1, 6.3.2,Table 6, 6.3.3, 8.6

Emergency Vehicle Management Service, 8.6

En-route Transit Information, 8.3

Environmental Sensor, 2.1.1, 4.1.2, 8.2



Ethernet, 4.7.1, 4.7.2, Table 5, 4.7.2, 7.3.2

Extended Range Two-way Communications, 4.5.2

FFault Monitoring, 4.6.3

Federal Environmental Protection Agency, 3.3.4

Fibre Optic Cable, 4.1.6, 4.7.2, Table 5, 7.3.2

Fibre Optic Link, 4.7.2

Fibre Optic Multiplexer, 4.7.1

Fibre Optic Network, 4.7.2

Field Controller, 3.7.2, 4.1.1, 4.1.2, 4.1.4, 4.7.2

Fire/Emergency, 3.1.3

Fire Services, 3.1.3, 6.2.1, 6.3.2, Table 6, 6.3.2,Table 8, 6.3.6

Fixed Rate Control, 4.3.1

Flashing Light, 3.1.3, 5.2.7

Flow Rate, 4.1.1

Freeway Incident Management Scenario, 6.3.2

Front-screen Projector, 6.2.2

Full Motion Video Transmission, 4.7.2

Fuzzy Logic, 4.1.5

GGIS (Geographic Information System), 4.2.3, 4.5.2,

Appendix A

GPS (Global Positioning System), 2.1.2, 4.1.8,4.2.3, 5.4, 6.3.3, 8.3, Appendix A

GUI (Graphical User Interface), 4.6.1, 4.7.1,Appendix A

HHAR (Highway Advisory Radio), 3.6.3, 3.7.2, 4.5.2,

4.7.1, 5.1.1, 5.2.2, 5.4, Appendix A

Hazardous Material, 3.1.3, 8.6

Headline Incidents, 3.1.3, 3.3.2, 3.5.1

Headway, 4.1.1, 4.1.2, Table 3

High Wind Warning, 2.6, 5.1.1

HOT (High Occupancy Toll), 3.6.2

HOV (High Occupancy Vehicle), 1.3, 3.6.2, 3.6.3,3.6.4, 4.3.1, 5.3, 5.5.2, 8.3, Appendix A,Appendix B

IILD (Inductive Loop Detection), 4.1.2, Table 3,

Appendix A

Imaging Sensor, 4.1.2

Impact Duration, 3.1.3

Incident Detection Algorithm, 4.1.4, 4.1.5, 4.5.4,6.3.3

Incident Duration, 3.1.3, 3.3.3, 6.3.2, Table 9

Incident Management, 2.3, Table 1, 3.6.1, 3.6.1,4.1.5, 4.1.9, 4.1.10, 4.1.11, 4.2.3, 4.3.2,4.6.2, 5.3, 6.3.2, 6.3.4, 6.3.5, 6.3.6, AppendixB

Incident Management Plan, 6.3.2, 6.3.2, 6.3.2,6.3.3, 6.3.5

Incident Management Response, 3.6.1, 3.6.3

Incident Management Strategies, 3.6.1, 3.6.1,6.3.2

Incident Management Systems, 3.6.1

Incident Response Plan, 3.6.4, 6.3.3

Incident Severity Level Matrix, 6.3.2, Table 7

Incident-to-detection, 3.1.3, 6.3.3

Incident-to-detection Time, 3.6.1, 6.3.3

Inductive Loop Detector, 2.1.2, 4.1.2

Information Collection, 1.3, 2.1, 2.6, 4, 4.1, 4.1.10,4.1.11

Interactive Telephone, 4.5.1, 6.2.1

Inter-agency Data, 4.7.1

Intermodal Freight Management, 8.5

International Border, 1.3, 5.3, 8.5

Internet, 2.5, 3.7.2, 4.4.1, 4.5.1, 4.5.4, 4.6.2,4.6.3, 4.7.2

In-vehicle Guidance, 4.5.2

ISP (Information Service Provider), 4.4.1, 4.5.2,Appendix A

ITCC (Integrated Transportation Control Centre),6.2.2, 6.2.4, 6.3.6



LLane Closure, 3.1.3, 3.3.1, 3.3.3, 4.1.2, Table 3,

5.2.7, 5.3, 6.2.1, 6.4

Lane Control, 2.6, 3.6.2., 3.6.4, 4.2.3, 5.1.4

Lane Management, 2.2, 3.6.3, 3.6.4, 4.2.4

Large Screen Display, 6.2.2, 6.2.4.2

LCS (Lane Control Sign), 2.2, 3.6.2, 4.2.4, 6.2.1,6.4, Appendix A

Level of Service, 3.2, 3.2.1, Table 1, 7.3.1, 8.3

Lighting, 3.1.1, 6.2.2

Local Detection Processing, 4.1.5

Local Diversion, 3.6.3, 6.3.3

Local Ramp Controller, 4.3.1

Logging, 4.6.1, 4.6.3

Loop Emulation, 4.1.2, Table 3

MMajor Incident, 3.1.3, 3.6.3, 6.2.5, 6.3.3, 6.3.6,

8.3

Manager, 4.1.12, 4.7.2, 6.1, 6.2.1

Microwave, 4.1.1, 4.1.2, Table 3, 4.1.3, 4.5.2,4.7.2, 5.2.8

Microwave Network, 4.7.2

Microwave Radar Detection, 4.1.2

Ministry of the Environment, 3.1.3, Table 6, Table 8

Minor Collisions, 3.1.3, 6.3.3

Minor Incidents, 3.1.3, Table 6

MM (Multi-mode) Fibre, 4.7.2, Table 5, Appendix A

Mobile Data Terminal, 6.3.3

Modem Rack, 6.2.2

MOE (Measures of Effectiveness), 3.3.1, 3.3.2,3.3.3, 7.2, 7.3, Table 9, Appendix A

Motorist Advisory Information, 5.2

Motorist Assistance Program, 6.2.1

MPEG (Motion Picture Experts Group), 4.1.6, 4.7.2,Appendix A

MTBF (Mean Time Between Failures), 7.3.2,Appendix A

MTTR (Mean Time To Repair), 7.3.2, Appendix A

NNetwork Management, 3.5, Table 1, 3.6.3, 4.7.2,

6.3.5, 7.2

Network Management Services, 6.2.1

Neural Network Approach, 4.1.5

NOX (Oxides of Nitrogen), 5.1.3, Appendix A

Non-diversion Strategies, 4.3.1

Non-injury Collision, 6.3.3, 8.6

Non-intrusive Detector, 2.1.1, 4.1.2, Table 3, 4.1.3

Non-recurrent Congestion, 2.4, 3.1, 3.1.3, 6.3.2,6.3.3

Noxious Fume Detection, 2.6, 5.1.3

NTCIP (National Transportation Communications forITS Protocol), 4.1.4, 4.1.6, 4.6.1, 4.7.1, 7.3.2,Appendix A

NTSC (National Television System Committee),4.1.6, Appendix A

OOccupancy, 2.1, 2.1.1, 3.1.2, 3.7.2, 4.1.1, 4.1.2,

Table 3, 4.1.4, 4.1.5, 4.3.1

Omni-directional Antenna, 4.7.2

On-board Safety Monitoring, 8.5

On-site Incident Response, 6.2.1

Operator, 3.1.3, 3.3.5, 3.4.6, 3.5.1, 3.6, 3.6.1,3.6.3, 3.6.5, 3.7.2, 4, 4.1.1, 4.1.2, 4.1.5, Table4, 4.1.6, 4.1.7, 4.1.10, 4.1.11, 4.2.2, 4.2.3,4.3.1, 4.6.1, 4.6.2, 4.6.3, 5.3, 6.1, 6.2.1,6.2.2, 6.2.4, 6.3.2, 6.3.3, 6.5, 6.5.2, 6.5.5,7.3.2, 8.2

OPP Police Services, Table 6, Table 8, Appendix A

OTDR (Optical Time Domain Reflectometer), 7.3.2

Overheight/Overweight Detection, 2.6, 5.1.2

PParking Guidance, 3.6.3

Passage Detector, 4.3.1

PASSER, 4.2.1

Passive Transponder, 4.1.8

Patrol Vehicle, 4.1.9, 6.3.2



Pattern Recognition Approach, 4.1.5

PEP (Privacy Enhancement Protocol), 6.5.2,Appendix A

Personal Digital Assistant, 2.5, 4.5.1

Point-to-multi-point, 4.7.1, 4.7.2

Point-to-point, 4.7.2, Table 5

Police Control, 6.3.2

Pre-emption, 4.2.3, 8.6

Pre-trip, 3.4.5, Table 1, 3.6.4, 3.7.2, 4.5, 4.5.1,5.3, 8.1

Pre-Trip Travel Information, 3.6.4

Priority Lane Facilities, 3.6.3

Private Citizen Calls, 4.1.10

Probe Vehicle, 4.1.8

Program Management, 3.4.8, 6.1

Projection Screen, 6.2.2

Proprietary Algorithms, 4.1.5

Public Domain Algorithms, 4.1.5

Public Transit Vehicle Location System, 4.2.3

Public Transport Management, 8.3

Public Travel Security, 8.3

QQueue Detector, Table 3, 4.3.1

Queue Warning Sign, Table 2, 3.7.2

QWS (Queue Warning System), 1.3, 4.7.1, 5.3,Figure 15, Appendix A

RRadio Propagation Analysis, 4.7.2

Raised Floor, 6.2.2

Ramp Control Signals, 4.3.1

Ramp Design, 4.3.1

Ramp Geometric, 4.3.1

Ramp Meter, 4.3.1

Real-time Information Collection, 4.1

Recovery, 3.1.3, 6.3.3

Recovery Time, 6.3.3

Recurrent Congestion, 2.4, 3.1, 3.1.2, 3.5.1, 4.3.1

Regulatory Messages, 4.2.4

RESCU (Road Emergency Services CommunicationsUnit), 1.3, 3.8, 4.1.5, Figure 6, Table 4, 4.6.2,4.7.1, 6.3.6, Appendix A

Response Level, 6.3.2, 6.3.3

Response-to-Clearance, 3.1.3, 6.3.3

Response-to-Clearance Time, 3.6.1, 6.3.3

RF (Radio Frequency) Modem, Table 3, 4.7.2, 7.3.2,Appendix A

Ride-matching/Carpooling, 3.6.4

Ride-matching and Reservation Services, 8.1

RMS (Ramp Metering System), 4.2.1, 4.7.1,Appendix A

Road Authority, 1.1, 3.5.2, 5.2.1, 5.2.3, Table 6

Road Maintenance, 3.1.3, 3.3.5, 3.4.10, 4.1.12,6.1, Table 6, 8.2

Road Reports, 5.2.3, Figure 14

Roadway Maintenance Management, 6.2.1

Route Balancing Strategies, 3.6.3

Route Guidance and Reservation Services, 8.1

ROW (Right-of-way), 2.2, 3.1.1, 3.3.1, 4.7.2,Appendix A

RTA (Roads and Traffic Authority), 4.2.2, Appendix A

Rubbernecking, 6.3.3

SSCATS (Sydney Coordinated Adaptive Traffic

System), 4.2.2, Appendix A

SCOOT (Split, Cycle, Offset Optimization Tool), 1.3,4.2.2, Appendix A

Secondary Incident, 3.1.3, 3.6.1, 6.3.2, 6.3.3,6.3.3, Table 9

Semi-active Transponder, 4.1.8

Sensor, 2.1, 2.1.1, 2.1.2, 3.7.2, 4.1.1, 4.1.2, Table3, 4.1.3, 4.1.4, 4.1.6, 4.1.8, 4.1.12, 5.2.7, 8,8.1, 8.2

Serial Interface, 4.7.2

Severity Level, 6.3.2, Table 7, Table 8

Signal Priority, 4.2.3, 8.3, 8.6

Situation/Visitor Room, 6.2.2, 6.2.4

Slide Projector, 6.2.2

SM (Single-Mode) Fibre, 4.7.2, Appendix A



Spread Spectrum Radio, 4.7.2

Static Trailblazer Signage, 3.5.1

Statistical Approach, 4.1.5

Storage, 3.6.1, 3.6.2, 4.3.1, 4.6.3, 6.2.2, 6.3.3

Strategic Diversion, 3.6.3

Strategic Traffic Management, 2.1, 6.2.1

System Development, 3.8, 6.1

System Maintenance, 6.1, 6.2.1

System Responsive Metering, 4.3.1

System Start-up, 4.6.3

System Technical Support, 6.1

System Technical Support Officer, 6.1

TTactical Diversion, 3.6.3

TCP/IP (Transmission Control Protocol/InternetProtocol), 4.7.1, Appendix A

TDM (Travel Demand Management), 3.6, Table 1,3.6.4, 6.3.5, Appendix A, Appendix B

TIA-232 Interface, 4.7.1

TIA-422 Interface, 4.7.1

Time-Based Coordination, 4.2.1, 4.2.2

Time-of-Day Control, 4.2.1

Time of Flight Detection, 4.1.2

Time to Return to Normal Operating Conditions,3.6.1

Time Series Model Approach, 4.1.5

Timing Plans, 3.5.1, 3.6.1, 4.2.1, 4.2.2, 4.2.3,4.6.4, 8.2

TOC (Traffic Operation Centre), 4.4.2, 4.6.2, 4.7.1,4.7.2, 5.3, 6.1, 6.2, 6.3.2, 6.3.3, 6.3.4, 6.3.5,6.3.6, 6.4, Appendix A

TOC Operator Services, 6.2.1

Toll Tag Reader, 4.7.1, 7.3.2

Towing, 3.1.3, 4.1.11, 6.2.1, 6.3.2, Table 6, 6.3.2,Table 8

Tracking, 4.1.2, Table 3, 4.1.5, 4.6.2, 6.3.2, 6.5.2,8.3, 8.5, 8.6

Traffic Adaptive Control, 4.2.1, 4.2.2

Traffic Engineer, 4.1.1, 6.1

Traffic Engineer/Supervisor, 6.1

Traffic Engineering, 1.2, 6.1, 6.2.1, 6.2.3

Traffic Management and Coordination, 6.1

Traffic Monitoring, 3.5.2, 3.6, 3.6.3, 4.1, 4.5.2,5.2.6, 5.4, 6.2.2, 6.5.2

Traffic Responsive Control, 4.2.1, 4.2.2, 4.3.1

Traffic Responsive Metering, 4.3.1

Traffic Signal Control, 1.3, 2.2, 3.6.1, 3.6.2, 4.2.1,4.2.3, 6.3.3

Traffic Signal Controller, 4.2.3, 4.7.1, 5.5

Traffic Signal Timing, 6.3.2

Traffic Supervisor/Coordinator, 6.1

Transit Management Centre, 2.5, 4.5.4

Transit Priority, 4.2.3

Transmission Media, 4.7.2, Table 5

Transponder, 2.1, 4.1.8, 6.3.3, 6.5.2, 8.4

TRANSYT, 4.2.1

Travel Speed, 3.6.4, 4.1.8, 4.3.1, Table 9, 8.5

Travel Time, 3.1.2, 3.4.2, 3.4.10, 3.5.1, Table 1,3.6.3, 4.1.2, 4.1.8, 4.3.1, 4.5.1, 4.5.2, 5.2.7,5.4, 6.3.3, 6.5.2, Table 9, 8.1, 8.4, 8.5, 8.6

Traveller Information Interface, 6.2.1

Traveller Information Services, 4.1.8, 4.5.1, 6.2.1,8.1

Traveller Information Service Provider, 6.2.1

Traveller Information System, 3.7.2, 4.5, Appendix B

Traveller Services and Reservations, 8.1

TRRL (Transport and Road Research Laboratory),4.2.2, Appendix A

Twisted Wire Pair (TWP) Cable Network, 4.7.2

Type 1 Transponder, 4.1.8

Type 170 controller, 4.1.4



UUMTS (Universal Mobile Telecommunication System)

4.1.8, Appendix A

Urban Traffic Control, 4.6.4



VVDS (Vehicle Detection System), 3.6, 3.7.2, 4.1.1,

4.1.2, 4.7.1, 4.7.2, Table 9, Appendix A

Vehicle Breakdown, 2.1.1, 3.1.3, 5.4

Vehicle Classification, 3.1.2, 4.1.1

Vehicle Collision, 3.1.3, 3.2.2, 5.4

Vehicle Count, 4.1.1, 4.1.2, Table 3

Vehicle Detection, Table 2, 4.1.2, Table 3, 4.3.1

Vehicle Detector, 2.2, 4.1, 4.1.2, 4.1.5, 4.3.1,4.5.4, 5.2.6, 5.5

Vehicle Operating Cost, 3.1.3, 3.6.1, 6.3.2

Vehicle Probes, 2.1, 2.1.2, 4.1, 4.1.2, Table 3,4.1.3, 4.1.8, 5.4, 8.3, 8.4, 8.5

Vehicle Speed, 2.1, 4.1.1, 4.1.2, 5.2.4

VID (Video Image Detection), 4.1.2, Figure 4, 5.2.6

Video Display, 6.2.5

Video/Graphics Display Monitor, 6.2.4

Video Link, 4.7.1, 4.7.2, Table 5

Video Modulators, 4.7.2

Video Network, 4.7.1, 4.7.2

Video Processor, 4.1.2

Video Transmission, 4.1.6, 4.7.1, 4.7.2, 7.3.2

Violation Enforcement, 6.5.2

Voice Network, 4.7.1

Voice Recorder, 6.2.4

Volume-Capacity (V/C) Ratio, 3.2.1, 3.3.2

VRC (Vehicle-to-Roadside Communications), 4.7.1,Appendix A

WWIM (Weigh in Motion), 4.7.1, 5.1.2, Appendix A

Wireless Network, 4.7.2

WLAN (Wireless Local Area Network) 4.7.2

Work Zone, 2.6, 3.2.1, 3.4.3, 3.5.1, 3.5.2, 5.2,5.2.1, 5.2.2, 5.2.4, 5.2.7, 5.2.8, Appendix B

YYagi Antenna, 4.7.2

Yellow Pages, 8.1



Appendix A – Definitions

Acronyms

AADT Annual Average Daily Traffic

ADSL Asymmetric Digital Subscriber Line

AGC Automatic Gain Control

AGPS Assisted Global Positioning System

AID Automatic Incident Detection

AMC Area Maintenance Contractor

APID All Purpose Incident Detection

APTS Advanced Public Transport Systems

ARWIS Advanced Road Weather InformationSystems

ATC Advanced Traffic Controller

ATIS Advanced Traveller information Systems

ATM Asynchronous Transfer Mode

ATMS Advanced Traffic Management Systems

AVI Automatic Vehicle Identification

AVL Automatic Vehicle Location

AWG American Wiring Gauge

CATV Cabled Television

CAD Computer Aided Dispatch

CC Camera Control

CCD Charged Coupled Device

CCIR Canadian Council of Insurance Regulators

CCTV Closed Circuit Television

CDPD Cellular Digital Packet Data

CO Carbon Monoxide

CORBA Common Object Request BrokerArchitecture

CRC Collision Reporting Centres

CPU Central Processing Units

CTCS Centralized Traffic Control Systems

CVO Commercial Vehicle Operations

CW Continuous Wave

DAB Digital Audio Broadcast

DCS Digital Communications Service

DES Double Exponential Smoothing

DHV Design Hour Volume

DMS Dynamic Message Signs

DSRC Dedicated Short Range Communications

ETC Electronic Toll Collection

FHWA U.S. Federal Highway Administration

FTMS Freeway Traffic Management Systems

GIS Geographic Information Systems

GPS Global Positioning System

GTA Greater Toronto Area

GUI Graphical User Interface

HAR Highway Advisory Radio

HCM Highway Capacity Manual

HOT High Occupancy Toll

HOV High Occupancy Vehicle

IEC International Electrotechnical Commission

ILD Inductive Loop Detection

IP Internet Protocol

ISO International Organization forStandardization

ISP Information Service Providers

ITE Institute of Transportation Engineers

ITS Intelligent Transportation Systems

JPEG Joint Photographic Experts Group

KHGSPM King’s Highway Guide Signing PolicyManual

LAN Local Area Network

LCS Lane Control Signs

LED Light Emitting Sign

MM Multi-Mode

MOEs Measures of Effectiveness

MPEG Motion Picture Experts Group

MTBF Mean Time Between Failures

MTO Ministry of Transportation Ontario



MTTR Mean Time To Repair

MUTCD Manual of Uniform Traffic Control Devices

NOx Oxides of Nitrogen

NTCIP National Transportation Communicationsfor ITS Protocol

NTSC National Television System Committee

OPP Ontario Provincial Police

OTDR Optical Time Domain Reflectometer

OTM Ontario Traffic Manual

PATREG Pattern Recognition

PEP Privacy Enforcement Protocol

PVMS Portable Variable Message Signs

QEW Queen Elizabeth Way

QWS Queue Warning Systems

RESCU Road Emergency ServicesCommunications Unit

RF Radio Frequency

RFP Request for Proposal

RFQ Request for Quotation

RMS Ramp Metering Systems

ROW Right-of-way

RTA Roads and Traffic Authority ofNew South Wales

SCATS Sydney Coordinated Adaptive TrafficSystem

SCOOT Split Cycle Offset Optimization Technique

SM Single-Mode

SMPTE Society of Motion Picture and TelevisionEngineers

SND Standard Normal Deviate

TCP Transmission Control Protocol

TDM Travel Demand Management

TOC Traffic Operation Centres

TRRL Transport and Road Research Laboratory

UPS Uninterruptible Power Supply

UMTS Universal Mobile TelecommunicationsSystem

UTP Unshielded Twisted Pair

V/C Volume-Capacity Ratio

VCR Video Cassette Recorder

VDS Vehicle Detection Systems

VID Video Image Detection

VIP Video Image Processing

VRC Vehicle-to-Roadside Communications

WIM Weigh-in-Motion



Definitions

A

Advanced Public Transport Systems (APTS)The application of advanced electronic andcommunications technologies to improve the safetyand efficiency of public transit systems. See alsoIntelligent Transportation Systems (ITS).

Advanced Road Weather Information Systems(ARWIS)These systems monitor the current road and weatherconditions using a combination of weather serviceinformation and data collected from environmentalsensors deployed on and about the roadway. Thecollected road weather information is monitored andanalysed to detect environmental hazards, and usedto more effectively deploy road maintenanceresources and issue general traveller advisories.

Advanced Traffic Management Systems(ATMS)Systems using high-technology devices, on bothfreeways and urban streets, to more efficientlymanage traffic. These include roadside sensors,ramp metering, cameras, dynamic message signs,HOV lanes and synchronized traffic signals thatrespond to traffic flows.

Advanced Traveller Information Systems (ATIS)This system provides travellers with information tohelp in trip planning and changing course en routeto bypass congestion, e.g., broadcast traffic reports,in-car computerized maps and highway DMSs. Alsocan include automated transit trip planning andautomated rideshare matching.

Automatic Incident Detection (AID)Automatic Incident Detection systems analyze trafficdata using algorithms to quickly and automaticallydetect incidents in order to improve the incidentresponse time. Algorithms can be based on a varietyof strategies and techniques.

C

Catastrophe Theory Approach(McMaster Algorithm)The Catastrophe Theory Approach is a techniqueused in Automatic Algorithm Detection. Thealgorithm uses traffic flow theory and CatastropheModels to forecast expected traffic conditions on thebasis of current traffic measurements for incidentand congestion detection.

Commercial Vehicle Operations (CVO)The application of advanced electronic andcommunications technologies to improve the safetyand efficiency of commercial vehicle/fleetoperations. See also Intelligent TransportationSystems (ITS).

ComprehensionThe ability of drivers to understand the meaning of asign message, including any symbols orabbreviations.

Congestion ManagementCongestion Management is an ATMS strategydesigned to mitigate the impacts of recurring andnon-recurring congestion. Components includecongestion monitoring, pre-trip and en-routeadvisory, lane management, and ramp metering.

ConspicuityThe ability of a traffic control device to attract orcommand attention, given the visual setting in whichit is placed.



Corridor ManagementThe process of managing and controlling trafficbetween/among parallel roads within a corridor.

D

Dynamic Message Sign (DMS)An array of sign technologies that have thecapability of displaying different messages to suitchanging conditions on the roadway. Included withinthe family of Dynamic Message Signs are full-matrixdisplays, single line or character-matrix displays,multiple pre-set message displays and simple on-offor “blank-out” displays. The terms “Changeable” and“Variable” are used in the OTM to describe specificsub-sets of Dynamic Message Signs.

E

Emergency Agency Response MatrixThe Emergency Agency Response Matrix is a toolused to aid in Incident Management. The matrixconsists of the various agencies involved on oneaxis, and the level of severity on the other axis. Byvisually associating the response requirements in thisway, the central command authority can quicklydetermine the appropriate process andresponsibilities.

F

Fault MonitoringEquipment is continuously monitored for failure.When a fault is detected, an alarm is raised, the faultis categorized, and the appropriate action is taken.

Fuzzy Logic ApproachA mathematical technique for dealing withimprecise data and problems that have manysolutions rather than one.

H

Headline IncidentsIncidents that tend to attract a significant amount ofmedia attention, such as severe collisions,dangerous goods spills, and traffic incidentsinvolving fatalities or heavy vehicles.

I

IncidentAn incident may be any of the following: trafficcollision, stalled vehicle, load spillage, or otheraction that affects one or more lanes of traffic. Acollision typically involves a moving vehicle strikingor being struck by another vehicle, person, or object.

Incident ManagementThe goal of Incident Management is to provide earlydetection and response to unscheduled events. Thecomponents are incident detection/confirmation,emergency response/motorist assistance, and pre-trip and en-route advisory.

Incident Severity Level MatrixThe Incident Severity Level Matrix is a tool used toaid in Incident Management. The matrix containsseveral levels of severity with the associatedcharacteristics. This allows for incidents to quicklybe ranked by severity so that the appropriateresponse can be implemented.



Intelligent Transportation Systems (ITS)A wide range of advanced electronics andcommunications technologies applied to roads andvehicles, designed to improve safety and decreasecongestion. When the term is applied to transit, it iscalled APTS; in commercial trucking, it is referred toas CVO.

L

Lane ManagementLane management involves the restriction of specificlanes of a roadway to designated vehicle types,direction of travel or other purposes. It involves theuse of Lane Control Signs (LCSs) and a centralcontrol and monitoring system. The primaryobjective is to maximize the capacity of existingroadway infrastructure for specific vehicles or toalter a direction of travel.

LegibilitySign legibility is governed by the distance at whichthe sign becomes legible and the duration for whichit remains legible. Legibility depends on character,word and line spacing, character height, font,contrast ratio and clarity of symbols.

Light-Emitting Diode (LED)Light-emitting diode or LED VMSs are currently thepreferred type of light-emitting sign technology. Thepixels for LED signs are comprised of multiple lightemitting diodes, which are solid state electronicdevices that glow when a voltage is applied.Adjusting the voltage that is transmitted to eachpixel controls the intensity of the light emitted fromeach LED pixel.

N

National Transportation Communications forITS Protocols (NTCIP)A family of communication protocols developed, orbeing developed, for the transportation community.

Network ManagementNetwork Management is an ATMS strategydesigned to balance the level of service within thenetwork as a function of current conditions.

Neural Network Approach(1) A non-linear approach used for designing

traffic applications.

(2) A non-linear mapping between a set of inputand output. For example, the approach canassociate patterns in traffic data with varioustraffic conditions. It offers an advantage overconventional incident detection algorithms inthat no mathematical model of trafficoperation or incident detection process isrequired, thus eliminating the imperfection inmodel formulation.

NOX

Oxides of nitrogen.

P

Pattern Recognition ApproachPattern recognition is a technique used in AutomaticIncident Detection. Algorithms compare trafficparameters between upstream and downstreamdetector stations.

PixelAn individual dot of light that is the basic unit fromwhich the images on a variable message sign aremade.



Portable Variable Message Sign (PVMS)Portable signs typically have the same functionalityand basic design as fixed location Variable MessageSigns and can be comprised of discrete charactersor full matrix arrangements.

Q

Queue Warning System (QWS)Queue Warning Systems are designed to provideadvanced warning of stopped or slow-moving traffic.The systems, also referred to as Queue-End WarningSystems, usually consist of Vehicle DetectionSystems, Dynamic Message Signs, communicationsand controller hardware, and use an algorithm todetermine the queue-end location.

R

Ramp MeteringA system used on a freeway or expressway entranceramp in which the rate of entry of vehicles onto thefreeway is metered by a traffic signal; the signalallows one vehicle to enter on each green indicationor green flash. The operation of the metering signalsis normally carried out only during rush hours and ina preferred direction (normally toward the CentralBusiness District (CBD) in the morning and outboundfrom it in the evening).

S

Secondary IncidentsWhen an incident occurs, there is an increased riskthat additional, secondary incidents will occur due tothe effects caused by the primary incident.

Statistical ApproachStatistical algorithms are used in some AutomaticIncident Detection strategies. Statistical analysisdetermines if the recorded traffic data differstatistically from the historical condition or definedthreshold.

T

Time Series Model ApproachThe Time Series Model is a technique used inAutomatic Incident Detection. Algorithms performcomparisons between short-term forecasts and theactual conditions, and identify calibrated deviationsas incidents.

Travel Demand ManagementImproving traffic flow by managing travel demandusing strategies such as congestion pricing andramp metering.

V

Variable Message Sign (VMS)A specific subset of Dynamic Message Signs. VMSsprovide the highest level of functionality of all of theDMSs. VMSs contain a variable display, made up ofa grid or matrix of discrete dots, known as Pixels.Combinations of pixels render the appearance of acontinuous formed character or graphic symbol. TheVMS can display a full array of alphanumericcharacters and symbols to form messagecombinations and can also have full graphicscapability.

Vehicle Detection System (VDS)Detects the presence of a vehicle and its attributesat a particular location and collects data used inmany ATMS applications.



Appendix B – References

An Intelligent Transportation Systems (ITS) Plan forCanada: En Route to Intelligent Mobility, TransportCanada, 1999

COMPASS Response Plan Database DevelopmentGuidelines, prepared for Ministry of TransportationOntario (MTO) by Delcan Corporation, 1992

Development of a Project Evaluation MethodologyFramework for Canadian Intelligent TransportationSystems, Final Report, Transport Canada, March2007

Developing Traveller Information Systems Using theNational ITS Architecture, Intelligent TransportationSystems Joint Program Office, U.S. Department ofTransportation, August 1998

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Advanced Traffic Management Systems - · PDF fileto exercise engineering judgement and...

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