Traffic Controls for Construction and Maintenance Work · PDF fileTRAFFIC MANUAL CHAPTER 5 ......

STATE OF CALIFORNIABUSINESS, TRANSPORTATION AND HOUSING

DEPARTMENT OF TRANSPORTATION

TRAFFIC MANUAL

CHAPTER 5TRAFFIC CONTROLS

forConstruction and Maintenance Work Zones

5-00 Table of Contents,List of Tables, Figures and Typical Applications

5-01 General Information

5-02 Temporary Traffic Control Elements

5-03 Pedestrian, Bicycle and Worker Considerations

5-04 Hand-Signaling Control

5-05 Types of Traffic Control Devices

5-06 Types of Temporary Traffic Control Zone Activities

5-07 Application of Devices

January, 1996(Revision 2)

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NOTICE

Caltrans publishes Standard Specifications, Standard SpecialProvisions, Standard Plans, etc., which contain specifications andrequirements for traffic control devices, including their use andplacement, when performing work on State highways. In some casesthose specifications and requirements may vary from, and be morestringent than those shown in this Manual. An example is the standard“T” series Traffic Control Plans, contained in the Standard Plans.Whenever there is a discrepancy between the specifications andrequirements contained in this Manual and those contained in thedocuments noted in the beginning of this paragraph for work on Statehighways, those documents shall govern.

INTRODUCTION

This Manual of Traffic Controls for Construction and Maintenance Work Zones (Manual) ispublished by the State of California, Department of Transportation (Caltrans), and is issued toprovide the basic standards for uniform types of warning signs, lights, and devices to be placedupon any public highway or street by any person engaged in performing work which interferes withthe movement of traffic upon such highway or street, in accordance with Section 21400 of theCalifornia Vehicle Code.

This Manual is also Chapter 5 of the Caltrans Traffic Manual (CTM), and is publishedseparately for easy reference.

Per the provisions of Sections 1598 and 1599 of the Construction Safety Orders in Title 8of the California Code of Regulations, this Manual is incorporated by reference as part of thoseregulations.

It is the responsibility of the Contractor or Organization performing work on, or adjacent to,a highway to install and maintain such devices which are necessary to provide passage for thetraveling public (including pedestrians and bicyclists) through the work, as well as for the safeguardof workers. Before work begins, traffic control plans, when developed for handling traffic througha construction or maintenance project, shall be approved by the Engineer of the public agency orauthority having jurisdiction over the highway.

Commonly used traffic control devices, conforming to specifications in the 1996 Manualmay continue in use until June, 1998. Thereafter, all such devices shall conform to the provisionsof this Manual (1996 Manual, Revision1).

Nothing contained in this Manual shall prevent Caltrans from modifying, changing, oradopting new specifications deemed necessary.

The text and figures shown in the Manual are not legal standards except as they describea device. Criteria for position, location, and use of traffic control devices is furnished solely for thepurpose of guidance and information, and is not a legal standard. Engineering judgment must beused to apply these guidelines and typical applications, or adjust them to fit individual field siteconditions.

Other reference material related to construction and maintenance zones can be found in theCaltrans Construction and Maintenance Manuals.

This Manual may be purchased from the California Department of Transportation,1900 Royal Oaks Drive, Sacramento, California 95815. Phone (916) 445-3520.

MEANINGS

“Shall”, “Should”, and “May”

In this document the words “shall”, “should”, and “may” are used to describe specificconditions concerning these devices. To clarify the meanings intended by the use of these words,the following definitions apply:

1. Shall - A mandatory condition. Where certain requirements in the design or application of thedevice are described with the “shall” stipulation, it is mandatory when an installation is madethat these requirements be met. Exceptions to these conditions on the State Highway Systemcan be approved on a case by case basis by the Manager, Traffic Operations Program or hisrepresentative. Documentation shall be provided.

2. Should - An advisory condition. Where the word “should” is used, it is considered to beadvisable usage, recommended but not mandatory.

3. May - A permissive condition. No requirement for design or application is intended.

Road Users

This Manual uses terms such as “traffic”, “motorists”, “vehicles”, “drivers”, and “road users.”These terms are used interchangeably and all are intended to include operators of motor vehicles,including bicyclists, as well as pedestrians.

COLOR CODE

The following color code establishes general meanings for eight colors in a total of twelvecolors that have been identified as being appropriate for use in conveying traffic control information.Central values and tolerance limits for each color are available.*

YELLOW - General WarningRED - Stop or prohibitionBLUE - Motorist services guidanceGREEN - Indicated movements permitted, direction, guidanceBROWN - Recreational and cultural interest guidanceORANGE - Construction and maintenance warningBLACK - RegulationWHITE - RegulationPURPLE - UnassignedSTRONG YELLOW GREEN - UnassignedLIGHT BLUE - UnassignedCORAL - Unassigned

The four colors for which no meaning has been assigned are being reserved for futureapplications. The meanings described above are of a general nature. More specific assignmentsof colors are given in the individual parts of this Manual relating to each class of devices.

(*) Available from the Federal Highway Administration (HTO 20), Washington D.C. 20590

1-1996

TRAFFIC CONTROLSTraffic Manual

CHAPTER 5TABLE OF CONTENTS

DateIndex No. Page No.

5-015-01.15-01.2

5-025-02.15-02.25-02.2A5-02.2B5-02.2C5-02.2D5-02.35-02.3A5-02.3B5-02.3C5-02.3D5-02.3E5-02.45-02.55-02.5A5-02.5B5-02.5C5-02.5D5-02.5E5-02.6

5-03

5-03.15-03.25-03.3

5-045-04.15-04.25-04.35-04.45-04.55-04.6

GENERAL INFORMATION.........................................................5-1Introduction............................................................................... 5-1Fundamental Principles............................................................. 5-1

TEMPORARY TRAFFIC CONTROL ELEMENTS.....................5-5Traffic Control Plans................................................................. 5-5Definitions of Temporary Traffic Control Zone Components...5-5

Advance Warning Area....................................................... 5-5Transition Area.................................................................... 5-6Activity Area....................................................................... 5-6Termination Area................................................................. 5-7

Tapers........................................................................................ 5-7Merging Taper..................................................................... 5-11Shifting Taper...................................................................... 5-11Shoulder Taper..................................................................... 5-11Downstream Taper............................................................... 5-11One-Lane, Two-Way Taper................................................. 5-11

Detours and Diversions............................................................. 5-13One-Lane, Two-Way Traffic Control........................................5-13

Flagger Method.................................................................... 5-13Flag Transfer Method.......................................................... 5-13Pilot Car Method.................................................................. 5-14Temporary Traffic Signal Method....................................... 5-14Stop or Yield Control Method............................................. 5-14

Transit Considerations...............................................................5-14

PEDESTRIAN, BICYCLE,AND WORKER CONSIDERATIONS..........................................5-15

Pedestrian Considerations..........................................................5-15Bicycle Considerations.............................................................. 5-16Worker Considerations.............................................................. 5-17

HAND-SIGNALING CONTROL.................................................. 5-18Function..................................................................................... 5-18Qualifications for Flaggers........................................................ 5-18High-Visibility Clothing............................................................5-19Hand-Signaling Devices............................................................ 5-19Hand-Signaling Procedures....................................................... 5-19Flagger Stations......................................................................... 5-20

January, 1996January, 1996

January, 1996January, 1996January, 1996 (Rev. 1)January, 1996January, 1996January, 1996January, 1996January, 1996 (Rev. 1)January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996

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5-0.1

(Rev. 2)

1-1996

TRAFFIC CONTROLS Traffic Manual

TABLE OF CONTENTS (Continued)


5-055-05.15-05.25-05.2A5-05.2B5-05.2C5-05.35-05.3A5-05.3B5-05.45-05.4A5-05.4B5-05.55-05.65-05.6A5-05.6B5-05.6B-15-05.6B-25-05.6C5-05.6C-15-05.6C-25-05.6D5-05.6D-15-05.6D-25-05.6E5-05.6E-15-05.6E-25-05.6F5-05.6F-15-05.6F-25-05.6G5-05.6H5-05.6I5-05.75-05.7A5-05.7B5-05.7C5-05.7D

TYPES OF TRAFFIC CONTROL DEVICES...............................5-22Design and Applications............................................................5-22Signs...........................................................................................5-22

Regulatory Signs.................................................................. 5-25Warning Signs...................................................................... 5-29Guide Signs.......................................................................... 5-37

Portable Changeable Message Signs......................................... 5-42Design...................................................................................5-42Application........................................................................... 5-44

Flashing Arrow Signs (Arrow Display).....................................5-45Flashing Arrow Sign Specifications.....................................5-45Flashing Arrow Sign Applications....................................... 5-45

High-Level Warning Devices.................................................... 5-47Channelizing Devices................................................................ 5-47

General..................................................................................5-47Cones.................................................................................... 5-48

Design............................................................................. 5-48Application......................................................................5-50

Portable Delineators............................................................. 5-50Design............................................................................. 5-50Application......................................................................5-50

Channelizers......................................................................... 5-51Design............................................................................. 5-51Application......................................................................5-51

Drums................................................................................... 5-51Design............................................................................. 5-51Application......................................................................5-52

Barricades.............................................................................5-52Design............................................................................. 5-52Application......................................................................5-53

Portable Barriers...................................................................5-53Temporary Raised Islands.................................................... 5-53Other Channelizing Devices.................................................5-54

Markings....................................................................................5-54Pavement Marking Applications.......................................... 5-54Interim Markings..................................................................5-55Raised Pavement Markers.................................................... 5-55Delineators............................................................................5-56

5-0.2

January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 2)January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996 (Rev. 1)January, 1996January, 1996 (Rev. 1)January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996 (Rev. 1)January, 1996January, 1996January, 1996 (Rev. 1)January, 1996January, 1996January, 1996 (Rev. 1)January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996January, 1996

(Rev. 2)

1-1996

TRAFFIC CONTROLSTraffic Manual 5-0.3



5-05.85-05.8A5-05.8B5-05.8C5-05.8D5-05.8E5-05.95-05.9A5-05.9B5-05.9C5-05.9D5-05.9E5-05.9F

5-06

5-06.15-06.25-06.35-06.3A5-06.3A-15-06.3A-25-06.3A-35-06.3A-45-06.3A-55-06.3B5-06.3C5-06.45-06.55-06.5A5-06.5B5-06.65-06.6A5-06.6B5-06.75-06.8

5-06.8A5-06.8B5-06.8C5-06.8D

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January, 1996January, 1996January, 1996January, 1996January, 1996

Lighting Devices........................................................................5-56Function................................................................................5-56Floodlights............................................................................5-56Portable Flashing Beacons................................................... 5-57Steady-Burning Electric Lamps........................................... 5-57Warning Lights.....................................................................5-58

Other Devices............................................................................ 5-58Crash Cushions.....................................................................5-58Portable Barriers...................................................................5-60Temporary or Portable Traffic Signals.................................5-60Rumble Strips....................................................................... 5-61Screens..................................................................................5-61Opposing Traffic Lane Dividers...........................................5-61

TYPES OF TEMPORARYTRAFFIC CONTROL ZONE ACTIVITIES..................................5-62

Introduction............................................................................... 5-62Typical Applications..................................................................5-62Selecting the Typical Application..............................................5-63

Duration of Work..................................................................5-63Long-Term Stationary Work...........................................5-63Intermediate-Term Stationary Work............................... 5-63Short-Term Stationary Work...........................................5-64Short Duration Work.......................................................5-64Mobile Work................................................................... 5-64

Location of Work................................................................. 5-65Roadway Type......................................................................5-65

Work Outside of the Shoulder................................................... 5-66Work on the Shoulder................................................................5-67

No Encroachment on Traveled Way.................................... 5-67Minor Encroachment on Traveled Way............................... 5-67

Work Within Traveled Way-Rural Two-Lane...........................5-67Detours................................................................................. 5-67One-Way Traffic Control..................................................... 5-68

Work Within Traveled Way-Urban Streets or Arterial............. 5-68Work Within Traveled Way-Rural or Urban,Multilane Divided and Undivided, Non-Access Controlled......5-68

Right Lane Closed................................................................ 5-69Left Lane Closed.................................................................. 5-69Multiple Lanes Closed..........................................................5-69Five-Lane Roads...................................................................5-70

(Rev. 2)

1-1996

TRAFFIC CONTROLS Traffic Manual5-0.4

CHAPTER 5LIST OF TABLES

TableNo.

Date

January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996

January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)

5-15-25-35-4

5-5a5-5b

Guidelines for Length of Longitudinal Buffer Space........................ 5-10Taper Length Criteria for Temporary Traffic Control Zones............ 5-10Suggested Advance Warning Sign Spacing.......................................5-31Taper Length, Buffer Space and Advance Warning SignSpacing Used in Typical Application Diagrams................................5-80Index to Typical Application Diagrams.............................................5-81Index to Typical Application Diagrams.............................................5-82

Page No.



5-06.95-06.105-06.10A5-06.10B

5-06.10C5-06.10D5-06.11

5-075-07.15-07.25-07.2A5-07.2B5-07.2C5-07.2C-15-07.2C-25-07.2D5-07.2E5-07.2F5-07.2F-15-07.2F-25-07.2F-35-07.2G5-07.2H5-07.3

Work Within Traveled Way-Intersections.................................5-70Work Within Traveled Way-Freeways and Expressways......... 5-70

Potential Problem Areas.......................................................5-71Two-Lane, Two-Way Traffic onOne Roadway of a Normally Divided Highway...................5-71Crossovers.............................................................................5-72Interchanges..........................................................................5-72

Control of Traffic Through Incident Areas................................5-73

APPLICATION OF DEVICES.......................................................5-74Typical Applications..................................................................5-74General Notes.............................................................................5-74

Work Performed on the Roadside (Outside Shoulder).........5-74Work Performed on Shoulders............................................. 5-75Mobile and Short-Duration Operations................................5-75

Short Duration.................................................................5-75Mobile Operations...........................................................5-76

Lane Closures on Two-Lane Roads......................................5-76Lane Closures on Multilane Roads.......................................5-76Work Performed in the Vicinity of Intersections..................5-77

Work Space on the Near Side of Intersections................5-77Work Space on the Far Side of Intersections.................. 5-77Work Space Within the Intersection................................5-77

Incident Management Situations.......................................... 5-78Features That May Be Added to the Diagrams.................... 5-78

Typical Application Diagrams...................................................5-78

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January, 1996January, 1996January, 1996January, 1996

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(Rev. 2)

1-1996

TRAFFIC CONTROLSTraffic Manual

CHAPTER 5LIST OF FIGURES

FigureNo.

Date

January, 1996January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996January, 1996 (Rev. 1)January, 1996January, 1996 (Rev. 1)January, 1996January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)

5-15-25-35-45-55-65-7a5-7b5-8a5-8b5-8c5-95-105-11

Component Parts of a Temporary Traffic Control Zone....................5-8Tapers and Buffer Space....................................................................5-9Example of a Two-Way Traffic Taper...............................................5-12Use of Hand-Signaling Devices by Flaggers..................................... 5-21Height and Lateral Location of Signs (Typical Installation)............. 5-23Method of Mounting Signs Other Than on Posts.............................. 5-24Commonly Used Regulatory Signs....................................................5-27Commonly Used Regulatory Signs....................................................5-28Warning Signs Used in Temporary Traffic Control Zones................5-38Warning Signs Used in Temporary Traffic Control Zones................5-39Warning Signs Used in Temporary Traffic Control Zones................5-40Flashing Arrow Sign Specifications.................................................. 5-46Barricades and Channelizing Devices............................................... 5-49Legend of Symbols Used in Typical Application Diagrams............. 5-83

Page No.

DatePage No.ApplicationNo.

CHAPTER 5LIST OF TYPICAL APPLICATIONS

TA 5-1TA 5-2TA 5-3TA 5-4TA 5-5TA 5-6TA 5-7TA 5-8TA 5-9TA 5-10TA 5-11TA 5-12TA 5-13TA 5-14TA 5-15

January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 2)January, 1996 (Rev. 2)January, 1996 (Rev. 1)January, 1996 (Rev. 1)

5-0.5

Work Beyond the Shoulder..........................................................5-85Blasting Zone...............................................................................5-87Work on Shoulders...................................................................... 5-89Mobile Operation on Shoulder.....................................................5-91Shoulder Closed on Limited Access Highway............................ 5-93Shoulder Work with Minor Encroachment..................................5-95Road Closed with On-Site Detour............................................... 5-97Road Closed with Off-Site Detour...............................................5-99Roads Open and Closed with Detour...........................................5-101Lane Closure on Two-Lane Road Using Flaggers.......................5-103Lane Closure on Low-Volume, Two-Lane Road.........................5-105Lane Closure on Two-Lane Road Using Traffic Signals.............5-107Temporary Road Closure.............................................................5-109Haul Road Crossing..................................................................... 5-111Work in Center of Low-Volume Road.........................................5-113

(Rev. 2)

1-1996

TRAFFIC CONTROLS Traffic Manual

LIST OF TYPICAL APPLICATIONS (Continued)

DatePage No.ApplicationNo.

TA 5-16TA 5-17TA 5-18TA 5-19TA 5-20TA 5-21TA 5-22TA 5-23TA 5-24TA 5-25TA 5-26TA 5-27TA 5-28TA 5-29TA 5-30TA 5-31TA 5-32TA 5-33TA 5-34TA 5-35

January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)January, 1996 (Rev. 1)

5-0.6

Surveying Along Centerline of Low-Volume Road.................... 5-115Mobile Operations on Two-Lane Road....................................... 5-117Lane Closure on Minor Street......................................................5-119Detour for One Travel Direction..................................................5-121Detour for Closed Street.............................................................. 5-123Lane Closure Near Side of Intersection....................................... 5-125Right Lane Closure Far Side of Intersection................................5-127Left Lane Closure Far Side of Intersection..................................5-129Half Road Closure Far Side of Intersection.................................5-131Multiple Lane Closures at Intersection........................................ 5-133Closure in Center of Intersection................................................. 5-135Closure at Side of Intersection.....................................................5-137Sidewalk Closures and Bypass Walkway....................................5-139Crosswalk Closures and Pedestrian Detours................................5-141Interior Lane Closure on Multilane Street....................................5-143Lane Closure on Streets With Uneven Directional Volumes...... 5-145Half Road Closure on Multilane High Speed Highways............ 5-147Lane Closure on Divided Highway..............................................5-149Lane Closure With Barrier...........................................................5-151Mobile Operation on Multilane Road..........................................5-153

(Rev. 2)

TRAFFIC CONTROLSTraffic Manual 5-11-1996

5-01.1 Introduction

During any time the normal function of aroadway is suspended, temporary traffic controlplanning must provide for continuity of function(movement of traffic, pedestrians, bicyclists, transitoperations, and access to property/utilities). Thelocation where the normal function of the roadwayis suspended is defined as the work space. Thework space is that portion of the roadway closed totraffic and set aside for workers, equipment, andmaterial. Sometimes there may be several workspaces within the project limits. This can beconfusing to drivers because the work spaces maybe separated by several miles. Each work spaceshould be signed to inform drivers of what toexpect.

Effective temporary traffic control enhancestraffic operations and efficiency, regardless ofwhether street construction, maintenance, utilitywork, or roadway incidents are taking place in thework space. Effective temporary traffic controlmust provide for the workers, road users, andpedestrians. At the same time, it must provide forthe efficient completion of whatever activitysuspended normal use of the roadway.

No one set of signs or other traffic controldevices can typically satisfy all conditions for agiven project. At the same time, defining detailedstandards that would be adequate to cover allapplications is simply not practical. This Manualdisplays several diagrams that depict commonapplications of standard temporary traffic controldevices. The traffic control selected for eachsituation should be based on type of highway,traffic conditions, duration of operation, physical

constraints, and the nearness of the work space totraffic.

Traffic control plans may be adopted by theauthority of a public body or official havingjurisdiction for guiding traffic. The plans anddevices should follow the principles set forth inthis Manual but may deviate from the typicaldrawings to allow for conditions and requirementsof a particular site or jurisdiction as determined bythe engineer.

The criteria of this Manual are intended toapply to both rural and urban areas. Rural highwaysare normally characterized by lower volumes,higher speeds, fewer turning conflicts, and fewerconflicts with pedestrians and bicyclists. Urbanstreet traffic is typically characterized by relativelylow speeds, wide ranges in traffic volume, narrowerroadway lanes, frequent intersections, significantpedestrian traffic, bicyclists and more roadsideobstacles.

It is essential that concern for traffic accidents,worker safety and efficiency of traffic movementform an integral element of every temporary trafficcontrol zone, from planning through completionof work activity. Simultaneously, the controlselected must permit efficient maintenance/construction of roadways and roadwayappurtenances.

5-01.2 Fundamental Principles

All traffic control devices used on street andhighway construction, maintenance, utility, orincident management (temporary traffic control)operations shall conform to the applicablespecifications of this Manual.

TRAFFIC CONTROLSFOR CONSTRUCTION AND MAINTENANCE

WORK ZONES

CHAPTER 5

General Information 5-01

(Rev. 1)

TRAFFIC CONTROLS Traffic Manual5-21-1996

Special plan preparation and coordination withtransit and other highway agencies, police andother emergency units, utilities, schools, railroads,etc. may be needed to receive input and support foradvising the motorists of the traffic operationsituations.

During temporary traffic control activities,commercial vehicles may need to follow a differentroute from automobiles because of bridge, weight,clearance, or geometric restrictions. Also, vehiclescarrying hazardous materials may need to followa different route from other vehicles. Truck RouteNational Network and hazardous cargo signs areincluded in Chapter 4 of the Caltrans TrafficManual.

Principles and procedures, which experiencehas shown to benefit the motorists, bicyclists,pedestrians, and workers in the vicinity oftemporary traffic control areas, are included in thefollowing listing. These principles and proceduresprovide a guiding philosophy, for the practitioner,of good temporary traffic control used in workzones. They do not establish specific standardsand warrants (individually addressed in thesucceeding sections of this Manual).

A. Traffic operations in temporary trafficcontrol areas should be an integral andhigh-priority element of every project fromplanning through design and construction.Similarly, maintenance and utility workshould be planned and conducted withmotorists, pedestrians, bicyclists, andworkers kept in mind at all times.Formulating specific plans for incidentmanagement traffic control is difficultbecause of the variety of situations that canarise. Nevertheless, plans should bedeveloped in sufficient detail to providefor motorists, pedestrians, bicyclists,workers, and enforcement/emergencypersonnel and equipment.

1. The basic principles governing thedesign of permanent roadways androadsides should also govern the designof temporary traffic control zones. Thegoal should be to route traffic throughsuch areas using geometrics and trafficcontrol devices comparable to thosefor normal highway situations.

2. A traffic control plan, in detailappropriate to the complexity of thework project or incident, should beprepared and understood by allresponsible parties before the site isoccupied. Any changes in the trafficcontrol plan shall be approved by anengineer.

B. Traffic movement should be disrupted aslittle as practicable.

1. Traffic control in work and incidentsites should be designed on theassumption that drivers will reducetheir speeds only if they clearly perceivea need to do so. Reduced speed zoningshould be avoided as much as practical.

2. Frequent and abrupt changes ingeometrics such as lane narrowing,dropped lanes, or main roadwaytransitions requiring rapid maneuversshould be avoided.

3. Provisions should be made foroperation of work or managementvehicles, particularly on high-speed,high-volume roadways.

4. Roadway occupancy and workcompletion time should be minimizedto reduce exposure to potentialconflicts.


5. Pedestrians and bicyclists should beprovided with access and passagethrough, or around, the temporarytraffic control zone at all times.

6 Construction or maintenance work onthe roadway should be scheduledduring off-peak hours and, if necessary,night work should be considered.

C. Drivers (including bicyclists) andpedestrians should be guided in a clear andpositive manner while approaching andspace traversing the temporary trafficcontrol zone.

1. Adequate warning, delineation, andchannelization by means of properpavement marking, signs, or use ofother devices that are effective undervarying conditions of light and weathershould be provided where appropriateto assure the driver and pedestrian havepositive guidance before approachingand while passing through the trafficcontrol zone.

2. Signs, pavement markings,channelizing devices, delineators, andother traffic control devices that areinconsistent with intended travel pathsthrough long-term work spaces shouldbe completely removed (see Section 5-05.7). In short-duration and mobilework spaces where retained permanentdevices are inconsistent with intendedtravel paths, attention should be givento devices that highlight or emphasizethe appropriate path.

3. Flagging procedures, when used, canprovide positive guidance to driverstraversing the temporary traffic control

zone. Flagging should be employedwhen all other methods of traffic controlare inadequate to warn and directdrivers.

D. To ensure acceptable levels of operation,routine inspection of traffic controlelements should be performed.

1. Only individuals who are trained and/or experienced in the principles oftraffic control should be assigned thatresponsibility at work sites. The mostimportant duty of these individuals isto ensure that all traffic controlmeasures implemented on the projectare necessary, conform to the trafficcontrol plan, and are effective inproviding for motorists, pedestrians,and workers.

2. Modification of traffic controls orworking conditions may be required toexpedite traffic movement and topromote worker safety. It is essentialthat the individual responsible fortraffic control have the authority tocontrol the progress of work on theproject with the authority to modifyconditions or halt work until applicableor remedial measures are taken.

3. Temporary traffic control zones shouldbe carefully monitored under varyingconditions of traffic volume, light, andweather to ensure that traffic controlmeasures are operating effectively andthat all devices used are clearly visible,clean, and in good repair.

4. When the need arises, an engineeringanalysis should be made (in cooperationwith law enforcement officials) of all


accidents occurring in temporary trafficcontrol zones. Temporary trafficcontrol zones and collision recordsshould be monitored to identify andanalyze traffic collisions or conflicts.For example, skid marks or damagedtraffic control devices may indicatethe need for changes in the trafficcontrol.

5. All traffic control devices should beremoved when no longer needed. Whenwork is suspended for short periods,advance warning signs that are nolonger appropriate shall be removed,covered, or turned, and otherinappropriate devices removed fromthe work zone so they are not visible todrivers.

E. The maintenance of temporary trafficcontrol zones requires attention during itslife because of the potential increase inconflicts.

1. To accommodate run-off-the-roadincidents, disabled vehicles, oremergency situations, it is desirable toprovide an unencumbered roadsiderecovery area.

2. Channelization of traffic should beaccomplished by pavement markings,signs, and/or lightweight channelizingdevices that will yield when hit byerrant vehicles.

3. Whenever practical, equipment,workers’ private vehicles, materials,and debris should be stored in such amanner as to reduce conflicts with run-off-the-road vehicles.

4. When pedestrian paths traverse throughthe temporary traffic control zone,temporary pedestrian facilities shouldbe developed to minimize pedestrianexposure to errant vehicles.

F. Each person whose actions affecttemporary traffic control zone from upper-level management personnel through fieldpersonnel should receive training and/orexperience appropriate to the job decisionseach is required to make. Only those whoare trained and/or experienced in trafficcontrol practices, and who have a basicunderstanding of the principles establishedby applicable standards and regulations,should supervise the selection, placement,and maintenance of traffic control devicesin work and incident management zones.

G. Maintaining good public relations isnecessary. The cooperation of the variousnews media in publicizing the existence ofand reasons for work sites can be of greatassistance in keeping the motoring publicwell informed.


5-02.1 Traffic Control Plans

Traffic Control Plans (TCP’s) play a vital rolein providing continuity for efficient traffic flow, tothe extent interruptions in normal flow arenecessary for temporary traffic control operationsor other events that must temporarily disrupt normaltraffic flow. Important auxiliary provisions thatcannot conveniently be specified on project planscan easily be incorporated into Special Provisionswithin the TCP. Also refer to the Caltrans HighwayDesign Manual Section 110.6.

A TCP describes traffic controls to be used forfacilitating all traffic through a temporary trafficcontrol zone. The plan may range in scope frombeing very detailed, to merely referencing typicaldrawings contained in this Manual, standardapproved highway agency drawings and manuals,or specific drawings contained in contractdocuments. The degree of detail in the TCPdepends entirely on the complexity of the situation,and TCP’s should be prepared by personsknowledgeable about the principles of temporarytraffic control and the work activities to beperformed.

Traffic control planning requires forethought.Provisions may be incorporated into the projectbid documents that enable contractors to developalternate traffic control plans, which may be usedonly if the responsible agency finds they are asgood as those provided in the plans/specifications.For maintenance and minor utility projects that donot require bidding, forethought must be given toselecting the best traffic control before occupyingthe temporary traffic control zone. Also,coordination must be made between projects toensure that duplicate signing is not used and toensure compatibility of traffic control betweenadjacent projects.

Modifications of TCP’s may be necessarybecause of changed conditions or determination ofeven better ways of handling traffic efficiently,

while permitting efficient temporary traffic controlactivities to progress.

5-02.2 Definitions of Temporary Traffic ControlZone Components

The temporary traffic control zone includesthe entire section of roadway between the firstadvance warning sign through the last traffic con-trol device, where traffic returns to its normal pathand conditions. Most temporary traffic controlzones can be divided into four areas: the advancewarning area, the transition area, the activity area,and the termination area. Figure 5-1 illustratesthese four areas.

The four components that constitute atemporary traffic control zone are described in theorder that drivers encounter them. They includethe following:

A. Advance Warning Area

In the advance warning area, drivers areinformed of what to expect. The advancewarning may vary from a single sign orflashing lights on a vehicle to a series ofsigns in advance of the temporary trafficcontrol zone transition area. On freewaysand expressways, where driver speed isgenerally in the higher range (70 km/h ormore), signs may be placed from 150 m to800 m or more before the temporary trafficcontrol zone. The true test of adequacy ofsign spacing is to evaluate how much timethe driver has to perceive and react to thecondition ahead. In this regard, the use ofspeed, roadway condition, and relateddriver expectancy must be considered inorder to derive a practical sign spacingdistance. Effective placement of warningsigns for urban and rural locals is as follows:

Temporary Traffic Control Elements 5-02


1. Urban

Warning sign spacings in advance ofthe transition area usually fall withinthe range of 1 to 2 times the speed (km/h) in meters, with the high end of therange being used when speeds arerelatively high. When two or moreadvance signs are used on higher-speedstreets such as major arterials, theadvance warning area should extend agreater distance. (See Table 5-3.)

2. Rural

Rural roadways are characterized byhigher speeds. Spacing for theplacement of warning signs is longer.Two or more advance warning signsare normally used in these conditions;the advance warning area should extend300 m or more in open highwayconditions. (See Table 5-3.) Advancewarning is normally not needed whenthe activity area is 9 m or greater fromthe driver’s path.

B. Transition Area

When redirection of the driver’s normalpath is required, traffic must be channelizedfrom the normal path to a new path. Thisredirection is intended to occur at thebeginning of the transition area. In mobileoperations, this transition area moves withthe work space. Transition areas usuallyinvolve strategic use of tapers, which arediscussed in more detail in Section 5-02.3.

C. Activity Area

The activity area is an area of roadwaywhere the work takes place. It is composedof the work space and the traffic space, andmay contain one or more buffer spaces.

1. Work Space

The work space is that portion of theroadway closed to traffic and set asidefor workers, equipment, and material.Work space may be fixed or may moveas work progresses. Long-term workspaces are usually delineated bychannelizing devices or shielded bybarriers to exclude traffic andpedestrians.

2. Traffic Space

The traffic space is the portion of theroadway in which traffic is routedthrough the activity area.

3. Buffer Space

The buffer space is an optional featurein the activity area that separates trafficflow from the work activity andprovides recovery space for an errantvehicle. Neither work activity norstorage of equipment, vehicles, ormaterial should occur in this space.Buffer spaces may be positionedlongitudinally and laterally, withrespect to the direction of traffic flow.

(Rev. 1)


a. Longitudinal Buffer Space

The longitudinal buffer space maybe placed in the initial portion of aclosed lane in advance of the workspace, as shown in Figure 5-1.When a protection vehicle is placedin advance of the work space, onlythe space upstream of the vehicleconstitutes the buffer space.

The longitudinal buffer space, asdepicted in Figure 5-2, should beused where a closed lane separatesopposing traffic flows. Typically,it is formed as a traffic island anddefined by channelizing devices.

A guide for the length oflongitudinal buffer space is shownin Table 5-1. The length may beadjusted to satisfy individualagency needs.

b. Lateral Buffer Space

A lateral buffer space may be usedto separate the traffic space fromthe work space, as shown in Figure5-1, such as an excavation orpavement drop-off. A lateral bufferspace also may be used betweentwo travel lanes, especially thosecarrying opposing flows. The widthof the lateral buffer space shouldbe determined by engineeringjudgment.

4. Incident Management Vehicle StorageSpace

When work occurs on a high-volume,highly congested facility in an urban

area, it is optional to allow space tostore emergency vehicles (e.g., towtrucks) to respond quickly to trafficincidents. The storage space is typicallyprovided at the beginning or end of theactivity area, or both. An emergencyvehicle storage area should not extendinto any portion of the buffer space.

D. Termination Area

The termination area is used to return trafficto the normal traffic path. The terminationarea extends from the downstream end ofthe work zone to the END ROAD WORKsigns (C14), if posted. Conditions may besuch that posting of END ROAD WORKsigns is not helpful. For example, theyshould normally not be used if othertemporary traffic control zones beginwithin 1500 m of the end of the work spacein rural areas, or about 500 m within urbanareas. For normal daytime maintenanceoperations, the END ROAD WORK signis optional. See also Section 5-05.2, C3,END CONSTRUCTION/ROAD WORKsign.

5-02.3 Tapers

A common important element of a temporarytraffic control zone is a roadway taper. Tapersmay be used in both the transition and terminationareas. Tapers are created using a series ofchannelizing devices or pavement markings placedto move traffic out of or into its normal path.Whenever tapers are to be used near interchangeramps, crossroads, curves, or other influencingfactors, it may be desirable to adjust the length oftapers. Longer tapers are not necessarily betterthan shorter tapers (particularly in urban areascharacterized by short block lengths, driveways,etc.), because extended tapers tend to encourage


Figure 5-1Component Parts of a Temporary Traffic Contol Zone

Termination Arealets traffic resume

normal driving

Activity Areais where worktakes place

Transition Areamoves traffic outof its normal path

Advance Warning Areatells traffic what to

expect ahead

Buffer Space(longitudinal)

provides protection fortraffic and workers

30 mDownstream Taper

Traffic Spaceallows traffic

to pass throughthe activity area

Buffer Space(lateral)

Work Spaceis set aside for

workers, equipment,and material storage


Figure 5-2Tapers and Buffer Space

LMerging Taper(See Table 5-2)

LongitudinalBuffer Space

(See Table 5-1)

1/2 LShifting Taper

(See Table 5-2)

1/3 L Shoulder Taper(See Table 5-2)

1/2 LShifting Taper

(See Table 5-2)


(See Table 5-1)

30 m Downstream Taper(See Table 2)


(See Table 5-1)

1/2 LShifting Taper

(See Table 5-2)

(Rev. 1)


Table 5-2Taper Length Criteria for Temporary Traffic Control Zones

Type of Taper Taper LengthUpstream Tapers

Merging Taper L MinimumShifting Taper 1/2 L MinimumShoulder Taper 1/3 L MinimumTwo-Way Traffic Taper 30 meters (100 feet) Maximum

Downstream Tapers(Use is optional) 30 meters (100 feet) Minimum

Formula for Taper Length 'L'(For State Highways, see Traffic Control Systems in the Caltrans Standard Plans.)

English

L = WS2 (40 mph or less) 60

L = WS (45 mph or greater)

L = Taper Length in feetW = Width of Offset in feetS = Speed in mph

Metric*

L = WS2 (65 km/h or less)150

L = 2 WS (70 km/h or greater)3

L = Taper Length in metersW = Width of Offset in metersS = Speed in km/h

S = Posted speed, off-peak 85th percentile speed prior to work starting, or the anticipated operating speed.

* The metric formulas result in larger values due to a rounding off of the constant in coverting the Englishformula to a Metric formula.

*Posted speed, off-peak 85th percentile speed prior to work starting, or the anticipated operating speed.

1Based upon American Association of State Highway and Transportation Officials (AASHTO) brakingdistance portion of stopping sight distance for wet and level pavements. This AASHTO document alsorecommends adjustments for the effect of grade on stopping and variation for trucks.

Table 5-1Guidelines for Length of Longitudinal Buffer Space1

Metric Measurements

Speed inKilometersPer Hour*

30405060708090

100110

101728436284

106136170

Length ofBuffer Space

(meters)

English Measurements

Speed inMiles

Per Hour*

2025303540455055606570

355585

120170220280335415485585


(feet)

(Rev. 1)


sluggish operation and to encourage drivers todelay lane changes unnecessarily. The real test oftaper length involves observation of driverperformance after traffic control plans are put intoeffect. Types of taper lengths are presented inTable 5-2. The maximum space in meters betweendevices in a taper numerically approximates one-fifth the speed in kilometers per hour. Types oftapers are shown in Figure 5-2 and the two-waytraffic taper is shown in Figure 5-3:

A. Merging Taper

A merging taper requires the longestdistances because drivers are required tomerge with an adjacent lane of traffic at theprevailing speed. The taper should be longenough to enable merging drivers to adjusttheir speeds and merge into a single lanebefore the end of the transition. Forfreeways, expressways, and other roadwayshaving a speed of greater than 65 km/h, theminimum length for merging tapers shouldbe computed by a formula L = 2/3WS. Forresidential, urban, and other streets withspeeds of 65 km/h or less, the formula L =(WS2)/150 should be used. Under eitherformula, L is the taper length in meters, Wis the lateral shift of traffic due to thepartially or fully closed lane (in meters),and S is the posted speed (in km/h), the off-peak 85th percentile speed prior to workstarting or the anticipated operating speed.The formula L = (WS2)/150 is used forspeeds of 65 km/h or less because slowertraffic can merge safely in a shorterdistance.

B. Shifting Taper

A shifting taper is used when merging isnot required, but a lateral shift is needed.Approximately one-half L has been found

to be adequate. Where more space isavailable, it may be beneficial to use longerdistances. Guidance for changes inalignment may also be accomplished byusing horizontal curves designed for normalhighway speeds.

C. Shoulder Taper

A shoulder taper may be beneficial onhigh-speed roadways with improvedshoulders that may be mistaken for drivinglanes (when work is occurring in, or near,the shoulder area). If used, shoulder tapersapproaching the activity area should havea length of about one-third L. If a shoulderis used as a travel lane either throughpractice or during a temporary trafficactivity, a normal merging or shifting tapershould be used. An example of a shouldertaper is presented in Figure 5-2.

D. Downstream Taper

The downstream taper may be useful intermination areas to provide a visual cue tothe driver that access is available to theoriginal lane/path that was closed. Whena downstream taper is used, it should havea maximum length of about (Rev. 1)30meters per lane, with devices spaced about6 meters apart. An example of adownstream taper is shown in Figure 5-2.

E. One-Lane, Two-Way Taper

The one-lane, two-way traffic taper is usedin advance of an activity area that occupiespart of a two-way roadway in such a waythat a portion of the road is used alternatelyby traffic in each direction. Typically,traffic is controlled by a temporary trafficsignal or a flagger. A short taper having a

(Rev. 1)


Work Space

Buffer Space (longitudinal) is usedto position the taper in advance of

the curve. See Table 5-1.

Two-Way Traffic Taper15 - 30 m

Flagger

Flagger

Figure 5-3Example of a Two-Way Traffic Taper

(Rev. 1)


maximum length of 30 m with channelizingdevices, or devices normal to centerline atapproximately 5 m spacings should beused to guide traffic into the one-way sec-tion. An example of a one-lane, two-waytraffic taper is presented in Figure 5-3.

5-02.4 Detours and Diversions

At detours, traffic is directed onto anotherroadway to bypass the temporary traffic controlzone. Detours should be signed clearly over theirentire length so that motorists can easily determinehow to return to the original roadway.

At diversions, traffic is directed onto atemporary roadway or alignment placed in or nextto the right-of-way, e.g., median crossovers orlane shifts.

5-02.5 One-Lane, Two-Way Traffic Control

Where traffic in both directions must, for alimited distance, use a single lane, provision shouldbe made for alternate one-way movement throughthe constricted section. Some means ofcoordinating movements at each end shall be usedto avoid head-on conflicts and to minimize delays.Control points at each end should be chosen topermit easy passing of opposing lines of vehicles.At a "spot" obstruction, however, such as an isolatedpavement patch on roadways with lower speedsand adequate sight distance, the movement may beself-regulating.

Alternate one-way traffic control may beaccomplished as appropriate by flagger control, aflag-carrying or official car, a pilot car, trafficsignals, or by using stop or yield control. Thissection discusses each of these traffic controltechniques. (See Section 5-04.2 for flaggerqualifications.)

A. Flagger Method

Where a one-lane two-way temporarytraffic control zone is short enough toallow visibility from one end to the other,traffic may be controlled by either a singleflagger or by a flagger at each end of thesection. When a single flagger is used, theflagger should be stationed on the shoulderopposite the obstruction or work space, orin a position where good visibility andtraffic control can be maintained at alltimes. When good visibility and trafficcontrol cannot be maintained by one flaggerstation, traffic may be controlled by aflagger at each end of the section. One ofthe flaggers should be designated as thecoordinator. Flaggers should be able tocommunicate orally or with signals. Thesesignals should not be mistaken for flaggingsignals. The use of radios may also bedesirable even though visual contact ispossible.

B. Flag Transfer Method

Flag carrying is effective when the routeis well defined. It should be employedonly when the one-way traffic is confinedto a relatively short length of road, usuallynot more than 1500 m in length. The driverof the last vehicle proceeding into the one-lane section is given a red flag (or othertoken) and instructed to deliver it to theflagger at the other end. The oppositeflagger, upon receipt of the flag, then knowsthat it is clear of vehicles coming from thatdirection and to allow traffic to move in theother direction. The flag being carriedshould always be clean and dry. A variationof this method is the use of an "official" carthat always follows the last vehicle


proceeding through the section. The use ofan official car eliminates the possibility ofloss of the flag.

C. Pilot Car Method

A pilot car is normally used to guide aqueue of vehicles through the morecomplex temporary traffic control zone ordetour. Its operation must be coordinatedwith flagging operations or other controlsat each end of the one-lane section.

The pilot car should have the name of thecontractor or contracting authorityprominently displayed. The PILOT CARFOLLOW ME sign (C26) shall be mountedat a conspicuous location on the rear of thevehicle.

Two or more pilot cars may be used toguide two-way traffic through a particularlycomplex detour.

D. Temporary Traffic Signal Method

Traffic signals may be used to controlvehicular traffic movements in temporarytraffic control zones. Traffic signals shouldalso be considered for half-width bridgereconstruction on low-to moderate-volumehighways. Typical applications include

highway or street intersections with atemporary haul road or equipment crossingand through areas requiring alternatingone-way traffic operations.

E. Stop or Yield Control Method

A yield or stop sign may be installed onlow volume, two-lane roads where oneside of the roadway is closed and the otherside must serve both directions. The sidethat is closed should yield to or stop foroncoming traffic on the side that is open.The approach to the side that is not closedmust be visible (for a distance equal to thesafe passing sight distance for thatapproach) to the driver who must yield orstop. See "No Passing Zones Markings" inChapter 6 of the Caltrans Traffic Manual.

5-02.6 Transit Considerations

Provision for effective continuity of transitservice needs to be incorporated into the temporarytraffic control planning process. Often times,public transit buses cannot efficiently be detouredin the same manner as other vehicles (particularlyfor short-term maintenance projects). On transitroutes, the TCP shall provide for features such astemporary bus stops, pull-outs, and waiting areasfor transit patrons.


5-03.1 Pedestrian Considerations

There are three threshold considerations inplanning for pedestrian in temporary traffic controlzones on highways and streets:

• Pedestrians should not be led into directconflicts with work site vehicles,equipment, or operations.

• Pedestrians should not be led into directconflicts with mainline traffic movingthrough or around the work site.

• Pedestrians should be provided with aconvenient travel path that replicates asnearly as possible the most desirablecharacteristics of sidewalks or footpaths.

In accommodating the needs of pedestrians atwork sites, it should always be remembered thatthe range of pedestrians that can be expected isvery wide, including the visually impaired, thehearing impaired, and those with walkingdisabilities. All pedestrians need protection frompotential injury and a smooth, clearly delineatedtravel path.

Therefore, every effort should be made toseparate pedestrian movement from both worksite activity and adjacent traffic. Wheneverpossible, signing should be used to directpedestrians to street crossings in advance of anencounter with a temporary traffic control zone.Signs should be placed at intersections so thatpedestrians, particularly in high-traffic-volumeurban and suburban areas, are not confronted withmid-block work sites that will induce them to skirtthe temporary traffic control zone or make a mid-block crossing. It must be recognized thatpedestrians will only infrequently retrace theirsteps to make a crossing. Consequently, ample

advance notification of sidewalk closures iscritically important. Refer to Figures TA-28 andTA-29, Section 5-07.3 for typical traffic controldevice usage and techniques for pedestrianmovement through work zones.

When pedestrian movement through or arounda work site is necessary, the aim of the engineershould be to provide a separate, footpath withoutabrupt changes in grade or terrain. Judicious useof special warning and control devices to warnmotorists may be helpful for certain difficult workzone situations. These include rumble strips,changeable message signs, hazard identificationbeacons, flags, and warning lights. Flaggeractivated audible warning devices may be used toalert pedestrians of the approach of erratic vehicles.Also, whenever it is feasible, closing off the worksite from pedestrian intrusions is preferable tochannelizing pedestrian traffic along the site solelywith temporary traffic control devices such ascones, portable delineators, barricades, or drums.If the possibility of vehicle impact is very low,chain link or other suitable fencing, placed wellaway from traffic, is acceptable. Solid fencingwith plywood, however, can create sight distancerestrictions at intersections and at work site accesscuts. Care must be taken not to create fenced areasthat are vulnerable to splintering or fragmentationby vehicle impacts. Similarly, temporary trafficcontrol devices used to delineate a temporarytraffic control zone pedestrian walkway must belightweight and, when struck, present a minimumthreat to pedestrians, workers, and impactingvehicles. Only minimally necessary ballastingwith lightweight materials should be used withthese devices.

Movement by work vehicles and equipmentacross designated pedestrian paths should beminimized and, when necessary, should becontrolled by flaggers or temporary traffic control.Cuts into work zones across pedestrian walkways

Pedestrian, Bicycle, and Worker Considerations 5-03


should be kept to a minimum, because they oftencreate unacceptable changes in grade and rough ormuddy terrain. Pedestrians cannot be expected totraverse these areas willingly. They will tend toavoid the cuts by attempting non-intersectioncrossings.

At work sites of significant duration, especiallyin urban areas with high pedestrian volumes, andwhere falling debris is a concern (such as work onoverhead structures), a canopied walkway isfrequently needed to protect pedestrians fromfalling debris. These covered walkways should besturdily constructed and adequately lit for nighttimeuse.

In places where pedestrians are judgedespecially vulnerable to impact by errant vehicles,all foot traffic should be separated and protectedby longitudinal barrier systems. Where a barrier isclearly needed, it should have sufficient strengthand low deflection characteristics, to keep vehiclesfrom intruding into the pedestrian space. Further,short, non-continuous segments of longitudinalsystems, such as concrete barriers, must be avoidedbecause they nullify the containment andredirective capabilities of the design, increase thepotential for serious injury to both vehicleoccupants and pedestrians, and encourage thepresence of blunt, leading ends. All upstreamleading ends that are present shall be appropriatelyflared or protected with properly installed andmaintained impact attenuators. With regard toconcrete barriers in particular, it is very importantto ensure that adjacent segments are properlyjoined to effect the overall strength required for thesystem to perform properly.

It has been determined through study andexperience that vertical curbs cannot preventvehicle intrusions into work zones. As aconsequence, normal vertical curbing is not asatisfactory substitute for positive barriers whenthese are clearly needed. Similarly, contractor-constructed wooden railings, chain-link fencingwith horizontal pipe runs, and similar systems

placed directly adjacent to vehicle traffic are notacceptable substitutes for crashworthy positivebarriers. In many instances, temporary positivebarriers may be necessary to prevent pedestriansfrom unauthorized movements into the active workzone and to prevent conflicts with traffic byeliminating the possibility of mid-block crossings.

If a high potential exists for vehicle incursionsinto the pedestrian space, judgment must beexercised as to whether to reroute pedestrians oruse barriers. Normally, standard traffic controldevices can satisfactorily delineate a temporarytraffic control zone pedestrian path, but fail-safechannelization can never be guaranteed with thesedevices because of the gaps between them. Tape,rope, or plastic chain strung between devices canhelp discourage pedestrian movements off thedesignated pathway.

Engineering judgment in each temporary trafficcontrol zone situation should readily determinethe extent of pedestrian needs. The engineer incharge of traffic control for temporary trafficcontrol zones should provide both a sense ofsecurity and safety for pedestrians walking pastwork sites and consistent, unambiguouschannelization to maintain foot traffic along thedesired travel paths.

5-03.2 Bicycle Considerations

There are several considerations in planningfor bicyclists in temporary traffic control zones onhighways and streets:

• A travel route that replicates the mostdesirable characteristics of a wide pavedshoulder or bikeway through or around thetraffic control zone is desirable forbicyclists.

• If the traffic control zone interrupts thecontinuity of an existing bikeway system,signs directing bicyclists through or around


the zone and back to the bikeway isdesirable.

• Unless a separate bike path through oraround the traffic control zone is provided,adequate roadway lane width to allowbicyclists and motor vehicles to travel sideby side through or around the zone isdesirable.

• Bicyclists should not be led into directconflicts with mainline traffic, work sitevehicles, or equipment moving through oraround the traffic control zone.

5-03.3 Worker Considerations

Of equal importance to the safety of the publictraveling through the temporary traffic controlzone is the safety of the worker performing themany varied tasks within the work site. Workzones present temporary and constantly changingconditions that may be unexpected by the traveler.Further, these work zone conditions almost alwayspresent situations that are different for the driver.This creates an even higher degree of vulnerabilityfor the personnel on or near the roadway.

Following the Fundamental Principles notedabove in Section 5-01.2 will usually provide thedegree of control and traffic operation that willbring about the best conditions for the worker. Ofparticular importance is maintaining work zoneswith traffic flow inhibited as little as possible,providing standard and clear traffic control devicesthat get the driver’s attention and provide positivedirection.

Below are key elements of traffic controlmanagement that should be considered in anyprocedure for assuring worker safety:

• Training. All workers should be trainedand/or experienced in how to work next totraffic in a way that minimizes their

vulnerability. In addition, workers withspecific traffic control responsibilitiesshould be trained and/or experienced intraffic control techniques, device usage,and placement.

• Worker Clothing. Workers exposed totraffic should be attired in bright, highlyvisible clothing similar to that of flaggers.See Section 5-04.3.

• Barriers. Barriers should be placed alongthe work space depending on such factorsas lateral clearance of workers fromadjacent traffic, speed of traffic, durationof operations, time of day, and volume oftraffic.

• Speed Reduction. In highly vulnerablesituations, consideration should be givento reducing the speed of traffic throughregulatory speed zoning, funneling, use ofpolice, lane reduction, or flaggers.

• Use of Police. In highly vulnerable worksituations, particularly those of relativelyshort duration, stationing police unitsheightens the awareness of passing trafficand will likely cause a reduction in travelspeed.

• Lighting. For nighttime work, lighting thework zone and approaches will allow thedriver better comprehension of therequirements being imposed. Care shouldbe taken to ensure that the lighting does notcause blinding.

• Special Devices. Judicious use of specialwarning and control devices may be helpfulfor certain difficult work zone situations.These include rumble strips, changeablemessage signs, flashing yellow beacons,


flags, and warning lights. Flagger activatedaudible warning devices may be used toalert workers to the approach of erraticvehicles. Misuse and overuse of specialdevices/techniques can greatly lessen theireffectiveness.

• Regulatory Signing. Usually, the use ofregulatory speed zone signing without lawenforcement has not shown affective.

• Public Information. Improved driverperformance may be realized through awell-prepared and complete publicrelations effort that covers the nature of thework, the time and duration of its execution,its anticipated effects on traffic, andpossible alternate routes and modes oftravel. Such programs have been found to

result in a significant drop in traffic; thatreduces the possible number of conflictsand may allow a temporary lane closingfor additional buffer space.

• Road Closure. If alternate routes areavailable to handle detoured traffic, theroad may be closed temporarily-which, inaddition to offering minimum worker/vehicle conflicts, may facilitate quickerproject completion and thus further reduceworker exposure.

Like other provisions of traffic control zoneset forth in this Manual, the various traffic controltechniques must be applied by qualified personsafter appropriate engineering studies and withsound engineering judgment and common sense.

5-04.1 Function

The primary function of traffic controlprocedures is to move vehicles and pedestriansthrough or around temporary traffic control zoneswhile protecting on-site workers and equipment.

5-04.2 Qualifications for Flaggers

Because flaggers are responsible for publicsafety and make the greatest number of publiccontacts of all highway workers, they should havethe following minimum qualifications:

• Sense of responsibility for the public andworkers.

• Training and/or experience in traffic controlpractices.

• Average intelligence.

• Good physical condition, including sightand hearing.

• Mental alertness and the ability to react inan emergency.

• Courteous but firm manner.

• Neat appearance.

Hand-Signaling Control 5-04

(Rev. 1)


5-04.3 High-Visibility Clothing

Flaggers shall wear orange, strong yellow-green, or fluorescent versions of these coloredwarning garments such as vests, jackets, or shirts.Rainwear, when worn, shall be orange, strongyellow-green, or yellow. During the hours ofdarkness, flaggers' stations shall be illuminatedsuch that the flagger will be clearly visible toapproaching traffic and flaggers shall be outfittedwith reflectorized garments. The retroreflectivematerial shall be visible at a minimum distance of1,000 ft. (304.8) m. The retroreflective clothing,or the retroreflective material added to the clothing,shall have a minimum of one horizontal stripearound the torso. White outer garments withretroreflective material may be worn during hoursof darkness in lieu of colored vests, jackets and/orshirts.

Uniformed law enforcement officers may beused as flaggers in some locations, such as anurban intersection, where enforcement of trafficmovements is important. Uniformed lawenforcement officers may also be used on freewayswhere traffic is channelled around work sites andit is necessary to assure that advisory and regulatoryspeeds are being enforced. For nighttime workand in low-visibility situations, a retroreflectivegarment as described above should be worn.

5-04.4 Hand-Signaling Devices

Hand-signaling devices, such as STOP/SLOWpaddles, lights, and red flags are used to controltraffic through temporary traffic control zones.The STOP/SLOW paddle, which gives driversmore positive guidance than red flags, shall be theprimary hand-signaling device. The standardSTOP/SLOW sign paddle shall be 450 mm wideand octagonal in shape with letters at least 150 mmhigh. A rigid handle should be provided. Thiscombination sign should be fabricated from lightsemirigid material, and shall have an octagonal

shape. The background of the STOP face shall bered with white letters and border. To improveconspicuity, the STOP/SLOW paddles may bemodified to incorporate on the STOP face, one ortwo symmetrically positioned flashing whitelight(s) on either the side of, or above and belowthe STOP legend. The light(s) may be activated bya demand switch or on/off switch. The backgroundof the SLOW face shall be orange with blackletters and border. When used at night, the STOP/SLOW paddle shall be retroreflectorized in thesame manner as signs.

Flags use shall be limited to emergencysituations. Flags used for signaling shall be aminimum of 600 mm square, made of a good gradeof red material, and securely fastened to a staffabout 900 mm long. The free edge should beweighted so the flag will hang vertically, even inheavy winds. When used at night, flags shall beretroreflective red.

5-04.5 Hand-Signaling Procedures

STOP/SLOW paddle and flag use are illustratedin Figure 5-4. The following methods of signalingwith STOP/SLOW paddles should be used:

• To Stop Traffic. The flagger shall facetraffic and extend the STOP sign paddle ina stationary position with the arm extendedhorizontally away from the body. The freearm should be raised with the palm towardapproaching traffic.

• To Direct Stopped Traffic to Proceed Theflagger shall face traffic with the SLOWpaddle held in a stationary position withthe arm extended horizontally away fromthe body. The flagger should motion withthe free hand for traffic to proceed.

• To Alert or Slow Traffic. The flagger shallface traffic with the SLOW sign paddle

(Rev. 1)


held in a stationary position with the armextended horizontally away from the body.The flagger may motion up and down withthe free hand, palm down, indicating thatthe vehicle should slow down.

The following methods of signaling with a flagshould be used:

• To Stop Traffic. The flagger shall facetraffic and extend the flag staff horizontallyacross the traffic lane in a stationaryposition, so that the full area of the flag isvisible hanging below the staff. The freearm should be raised with the palm towardapproaching traffic.

• To Direct Stopped Traffic to Proceed. Theflagger shall face traffic with the flag andarm lowered from view of the driver. Withthe free hand, the flagger should motiontraffic to proceed. Flags shall not be usedto signal traffic to proceed.

• To Alert or Slow Traffic. The flagger shallface traffic and slowly wave the flag in asweeping motion of the extended arm fromshoulder level to straight down, withoutraising the arm above a horizontal position.

5-04.6 Flagger Stations

Flagger stations shall be located far enoughahead of the work space so that approaching traffichas sufficient distance to stop before entering thework space. Table 5-1, Guidelines for Length ofLongitudinal Buffer Space, may be used forlocating flagger stations in advance of the workspace.

This distance is related to approach speeds,friction factors, and pavement and tire conditions.These distances may be increased for downgrades.1

The flagger should stand either on the shoulderadjacent to the traffic being controlled or in thebarricaded lane. At a “spot” obstruction, a positionmay have to be taken on the shoulder opposite thebarricaded section to operate effectively. A flaggershould stand only in the lane being used by movingtraffic after traffic has stopped, and the flaggerneeds to be visible to other traffic or to communicatewith drivers. Because of the various roadwaygeometrics, flaggers should be clearly visible toapproaching traffic at all times. For this reason theflagger should stand alone.

Other workers should not be permitted tocongregate around the flagger station. The flaggershould be stationed far enough ahead of the workforce to warn them (for example with horns,whistles etc.) of approaching danger, such asvehicles out of control.

Flagger stations should be visible far enoughahead to permit all vehicles to stop. Table 5-1,Guidelines for Length of Longitudinal BufferSpace, may be used in selecting the location offlaggers. This distance is related to approachspeeds, friction factors, and pavement and tireconditions. These distances may be increased fordowngrades.1 These distances are calculated in amanner similar to those calculated in the firstparagraph of 5-04.6. Flagger stations should bepreceded by proper advance warning signs. Undercertain geometric and traffic situations, more thanone flagger station may be required for eachdirection of traffic.

During hours of darkness, flagger stationsshall be illuminated such that the flagger will beclearly visible to approaching traffic. Lights forilluminating the station shall be approved by theEngineer of the public agency or authority havingjurisdiction over the highway. At two-way,unusually low-volume and/or unusually low-speedshort lane closings where adequate sight distanceis available for the safe handling of traffic, the useof one flagger may be sufficient.

1 Table III-2. A Policy on Geometric Design of Highwaysand Streets, AASHTO, 1990, p.125.


(Rev. 1)

Figure 5-4Use of Hand-Signaling Devices by Flaggers

STOP

450 mmMin.

PREFERRED METHOD

Paddle

EMERGENCY USE ONLY

Flag

To Stop Traffic

Traffic Proceed

To Alert andSlow Traffic

600 mm

600 mm

0.9 mSTOP

SLOW

SLOW


5-05.1 Design and Applications

The design and applications of traffic controldevices used in temporary traffic control zones aredescribed in this Manual. A traffic control deviceis a sign, signal, marking or other device placed onor adjacent to a street or highway (by authority ofa public body or official having jurisdiction) toregulate, warn, or guide traffic. Specificcrashworthy information on devices described inthis chapter can be found in the AASHTO RoadsideDesign Guide.1

Where the color orange is specified, fluorescentred-orange or fluorescent yellow-orange colorsmay be used. The fluorescent versions of orangeprovide higher conspicuity than standard orange,especially during twilight.

5-05.2 Signs

Temporary traffic control zone signs conveyboth general and specific messages by means ofwords or symbols and have the same threecategories as all traffic signs: namely, regulatorysigns, warning signs, and guide signs. Regulatorysigns shall have a black legend on a whitebackground. Warning signs in temporary trafficcontrol zones shall have a black legend on anorange background. Existing yellow warningsigns within the traffic control zone which are stillapplicable may remain in place. Guide signs shallhave a white legend on a green background, exceptfor special information signs as noted below inSection 5-05.2C.

All signs used at night shall be eitherretroreflective, with a material that has a smooth,sealed outer surface, or illuminated to show similar

shape and color both day and night. Signillumination may be either internal or external.Roadway lighting does not meet the requirementsfor sign illumination.

Standard orange flags, flashing yellow beacons,or Type B high-intensity flashing warning lightsmay be used in conjunction with signs. However,they must not block the sign legend.

The dimensions of signs shown herein are forstandard sizes, which may be increased wherevernecessary for greater legibility or emphasis. Onsecondary highways and city streets, smaller signsmay be used if authorized by lawful authority.Deviations from standard sizes as prescribed hereinshall be in 150 mm increments. Sign design detailsare contained in the Caltrans Traffic SignSpecifications.2

Special signs may be needed based on anengineering analysis. They should conform to thestandards for color, shape, and alphabet size andseries. The sign message should be brief, legible,and clear.

As a general rule, signs should be located onthe right-hand side of the roadway. When specialemphasis is needed, signs may be placed on boththe left and right sides of the roadway. Signs maybe mounted on portable supports placed within theroadway itself. Signs, although ordinarily mountedon posts, may also be mounted on or abovebarricades.

Guidelines for height and lateral clearance oftemporary post-mounted roadside signs are shownin Figure 5-5. Signs erected at the side of the roadshould be mounted at a height of at least 2.1 m,measured from the bottom of the sign to the nearedge of the pavement. The height to the bottom of

1 AASHTO, 44 North Capitol Street, N.W., Suite 225,Washington, D.C. 20001.

2 Traffic Sign Specifications are available from theCalifornia Department of Transportation PublicationsDistribution Unit, 1900 Royal Oaks Drive, Sacramento,CA 95815. Telephone (916) 445-3520.

Types of Traffic Control Devices 5-05

(Rev. 1)


Figure 5-5Height and Lateral Location of Signs

(Typical Installation)

ROADWORKAHEAD

1.8 -3.6 m

2.1 mMinimum

RURAL DISTRICT

1.8 -3.6 m

1.8 mMinimum

RURAL DISTRICT WITHADVISORY SPEED PLATE

1.8m

35MPH

DETOUR500 FT

0.6 mMinimum 2.1 m

Minimum

URBAN DISTRICT

0.6 mMinimum 2.1 m

Minimum

URBAN DISTRICT

Paved Shoulder

Walkway

ROADCLOSED500 FT

RIGHT LANECLOSED1000 FT


Figure 5-6Methods of Mounting Signs Other Than on Posts

2.4 m Min.

High Level Warning Device(Flag Tree/Sign Optional)

PORTABLE AND TEMPORARY MOUNTINGS

Warning Light(Optional)

0.3 m Min.

UTILITYWORKAHEAD

0.3 m Min.

BARRICADES

(Rev. 1)


a secondary sign mounted below another sign maybe 300 mm less than the appropriate height specifiedabove.

Methods of mounting signs other than on postsare illustrated in Figure 5-6. Signs may be mountedon portable supports for short-term, short-duration,and mobile conditions (see Section 5-06.2). Signsmounted on Type III barricades should not covermore than 50 percent of the top two rails or 33percent of the total area of the three rails.Unprotected sign systems should be crashworthy.The bottom of signs mounted on barricades ortemporary supports shall be no less than 300 mmabove the traveled way.

For the best mobility of maintenanceoperations, a large sign may be mounted on amaintenance vehicle stationed in advance of thework or moving along with it. This may be eitherthe work vehicle or the protection vehicle. Amobile sign display may be mounted on a trailer.

Signs used in temporary traffic control zonesare moved frequently, loaded and unloaded fromtrucks, and in general receive much harshertreatment than permanent signs. For this reason,particular attention must be given to maintainingsigns properly for cleanliness, visibility, and correctpositioning. Signs that are excessively worn,scratched, bent, or have lost a significant amountof retroreflectivity should be promptly replaced.

A. Regulatory Signs

1. Authority

Regulatory signs inform highway usersof traffic laws or regulations andindicate the applicability of legalrequirements that would not otherwisebe apparent. Because regulatory signsimpose legal obligations on all drivers,they shall be authorized by the publicbody or official having jurisdiction.

2. Design

Regulatory signs are generally rectan-gular, with a black legend and borderon a white background. Exceptionsinclude the STOP sign, the YIELDsign, the DO NOT ENTER sign, theWRONG WAY sign, and the one-wayarrow sign. The one-way arrow signmay be either a horizontal or verticalrectangular plate. Regulatory signsare illustrated in Figures 5-7a and 5-7b. Design details for all regulatorysigns are given in the Caltrans SignSpecifications. (See footnote 2, pg. 22)

3. Application

If temporary traffic control zonesrequire regulatory measures differentfrom those normally in effect, theexisting permanent regulatory devicesshall be temporarily removed orcovered and superseded by theappropriate temporary regulatory signsand shall follow applicable ordinancesor statutes of the jurisdiction, as well ascomply with the sign design standardsof the Caltrans Traffic Manual.

4. ROAD CLOSED Sign (C2)

The ROAD CLOSED sign shall beused where the roadway is closed to alltraffic except contractors’ equipmentor officially authorized vehicles andmay be accompanied by appropriatedetour signing. The sign should beerected at or near the center of theroadway on or above a Type IIIbarricade that closes the roadway(Section 5-05). The sign should have


a minimum size of 1200 mm by 750mm. The words RAMP CLOSED orBRIDGE CLOSED may be substitutedfor ROAD CLOSED, whereapplicable. The ROAD CLOSED signshall not be used where traffic ismaintained or where the actual closingis some distance beyond this sign.

C2

CLOSEDROAD

ROAD CLOSED10 MILES AHEAD

LOCAL TRAFFIC ONLY

C3

R20 R20B

R20D

OVER__AXLES

OVER__TONSOVER

60 FT LONG

OVER96" WIDE

WEIGHTLIMIT

8 T12 T16 T

C3A

ROAD CLOSEDTO

THRU TRAFFIC

5. LOCAL TRAFFIC ONLY Signs (C3, C3A)

The LOCAL TRAFFIC ONLY signsshould be used where through trafficmust detour to avoid a closing somedistance beyond the sign, but wherelocal traffic can move up to point ofclosure. The sign shall carry the legendROAD CLOSED [XX] MILESAHEAD–LOCAL TRAFFIC ONLYor, optionally for urban use, ROADCLOSED TO THRU TRAFFIC, andshould be accompanied by appropriatewarning and detour signing. The wordsRAMP CLOSED or BRIDGECLOSED may be substituted forROAD CLOSED where applicable.

6. WEIGHT LIMIT Signs (R20, R20BR20D)

A WEIGHT LIMIT sign shows thegross weight or weight per axle thatcan be permitted on the roadway orbridge. Weight restrictions should beconsistent with state or local regulationsand shall not be imposed without theapproval of the authority havingjurisdiction over the highway. Whenweight restrictions are imposed, amarked detour should be provided forvehicles weighing more than the limitposted.

TRAFFIC CONTROLSTraffic Manual1-1996

5-27

Figure 5-7aCommonly Used Regulatory Signs

SPEEDLIMIT

END

35

LEFT LANE

TURN LEFT

MUST

ONLY

R1-2

R3

R18-2

R61-1.1

SPEEDLIMIT

50

NOTURNS

NOTPASS

DO

R2

R15

R34

R63

ZONEAHEAD

35

ONLY

WITHCARE

PASS

R2-4

R16

R59

R64

STOP

SPEEDAHEAD

REDUCED

R1

R2-5

R17

R60A

YEILD

TRAFFIC CONTROLS Traffic Manual1-1996

5-28

Figure 5-7bCommonly Used Regulatory Signs

R7

ONEWAY

R10AR10

ONE WAY

DO NOT

ENTERWRONG

WAYP

R11 R11A R26D

STOPHERE ON

RED

R90

ONCOMINGTO

TRAFFIC

SIDEWALK CLOSED

CROSS HERE

SIDEWALK CLOSED

USE OTHER SIDE

SR51 C42 C42(Alternate Message)

(Rev. 1)


5-29

7. Special Regulatory Signs

Special word message regulatory signsmay be needed based on an engineeringanalysis. The sign should conform tothe standards for color, shape, andalphabet size and series. The signmessage should be brief, legible, andclear.

Regulatory speed limits are establishedby an engineering analysis which mayinclude a traffic and engineering survey.Chapter 8 of the Caltrans TrafficManual should be consulted beforetemporary traffic control zoneregulatory speed limits are established.Also, an enhanced enforcementprogram may need to be considered.

B. Warning Signs

1. Function

Temporary traffic control zone warningsigns notify drivers of general orspecific conditions on or adjacent to aroadway.

2. Design and Application

With some exceptions, warning signsshall be diamond shaped with a blacksymbol or message on an orangebackground. Mounting or spaceconsiderations may justify a changefrom the standard diamond shape, butsuch variations require prior approvalof the highway authority.

Warning signs developed exclusivelyand used for incident management shallhave an orange background. However,in emergencies, available signs havingyellow backgrounds may be used iforange signs are not readily available.Sign sizes for various type facilitiescan be found in the Caltrans TrafficSign Specifications. (See footnote 2,pg. 22.)

Where any part of the roadway isobstructed or closed, advance warningsigns are required to alert traffic well inadvance of these obstructions orrestrictions. These signs may be usedsingly or in combination. Because oftheir importance, they shall have astandard size of 1200 mm square andshall be the standard diamond shapefor warning signs, except as providedabove. Signs larger than 1200 mmsquare may be used for additionalemphasis of the temporary trafficcontrol zone.

Where speeds and volumes aremoderately low, a minimum size of900 mm square may be used for advancewarning signs, if they have a minimumletter size of 125 mm.

On secondary roads or city streets wherespeeds are very low, signs smaller thanthe standard size, but not less than 600mm square, may be used for warningsigns having short word messages orclearly understood symbols.

(Rev. 2)


5-30

Where distances are not shown onwarning signs as part of the message, aseparate panel with the distance legendmay be mounted immediately belowthe sign on the same support.

3. Spacing of warning signs is covered inSection 5-07.3 Typical ApplicationDiagrams.

Where highway conditions permit,warning signs should be placed atvarying distances in advance of thework zone, depending on the roadwaytype, condition, and speed. Where aseries of two or more warning signs isused, the closest sign to the work zoneshould be placed approximately 60 maway for low-speed urban streets to300 m away or more for freeways andexpressways.

Table 5-3 presents the suggestedspacing of warning signs for fourgeneral roadway types for use inSection 5-07.3, Typical ApplicationDiagrams. Actual sign spacing mustbe tempered by engineering judgementbased on site specific conditions.

In Table 5-3, the column headings "A","B", and "C" are the dimensions forwarning sign spacings for use in Section5-07.3, Typical Application Diagrams.The dimensions are for marking thelocations of warning signs relative tothe transition or point of restriction.

• The "A" dimension is for thedistance from the work zone to thesign nearest the work zone.

• The "B" dimension is for the nextsign upstream of the transition orrestriction.

• The "C" dimension is for the firstsign (in a three-sign series) that thedriver encounters in a temporarytraffic control zone.

4. Other Approach Warning Signs

Certain conditions require otheradvance warning signs, such as limitedsight distance or because an obstructionmay require a motorist to stop. Thereare no specified standards for suchsigns. The determination of the sign orsigns to be used shall be based on anengineering study using the followingsections as guidelines. As an alternativeto a specific distance on these advancewarning signs, the word AHEAD maybe used.

5. Application of Warning Signs forMaintenance, Minor Road Work, andUtility Sites

At many maintenance, minor roadwork, and utility sites, particularly onlightly traveled roads, the sequence ofadvance warning signs prescribed formajor road work may not be needed.The signs described in the followingsections will usually provide sufficientadvance warning in such situations,either by themselves or with otheradvance warning signs.

Maintenance or minor road work canoccur within the temporary trafficcontrol zone limits of a major project.


5-31

Table 5-3Suggested Advance Warning Sign Spacing

Maintenance or minor road workwarning signs may be needed whentraffic is permitted through such zones.Maintenance and minor road worksigning and traffic control should becoordinated with appropriateauthorities so that drivers are notconfused or misled by additional trafficcontrol devices.

6. ROAD CONSTRUCTION/WORKAHEAD Sign (C18/C23)

Either the C18 (CONSTRUCTION)or C23 (WORK) sign should be usedin advance of a construction ormaintenance project to serve as ageneral warning of the work zone.

The third line may be altered to read500 ft., 1000 ft, etc., as appropriate,with a C29 plate.

The C23 sign is also available with themessage RAMP WORK AHEAD.

7. DETOUR AHEAD Sign (C1)

The DETOUR AHEAD sign shall beused in advance of a point where trafficis diverted around the work zone overa temporary roadway or route. (SeeCVC 21363).

1500 FT

C23

ROADWORKAHEAD

C29

Note: These are suggested distances for Advance Warning Signs, adequate sight distances andproximity to other roadway features may dictate the need for adjustments when placed.

Urban-40 km/h (25 mph) or less 60 (200) 60 (200) 60 (200)Urban-50 km/h (30 mph) or more 100 (350) 100 (350) 100 (350)Rural 150 (500) 150 (500) 150 (500)Expressway/Freeway 300 (1000) 300 (1000) 300 (1000)

Distance Between Signsin Meters (Feet)Road Type

A B C


5-32

The second line may be altered to read500 ft., 1000 ft, etc., as appropriate.

8. ROAD CLOSED AHEAD Sign (C19)

The ROAD CLOSED AHEAD sign isused in advance of that point where ahighway is closed to all traffic or to allbut local traffic.

The third line may be altered to read500 ft., 1000 ft., etc., as appropriate,with a C29 plate

The C19 sign is also available with themessage RAMP CLOSED AHEAD.

9. ONE LANE ROAD AHEAD Sign(C16)

The ONE LANE ROAD AHEAD signshould be used ahead of that pointwhere traffic in both directions mustuse a common single lane. See Figure5-3. If the affected one-lane roadwayis not visible from one end to the other,or if the traffic is such that simultaneousarrivals at both ends occur frequently,flagging procedures or signal controlshould be used to control alternatetraffic flows.

The third line may be altered to read500 ft., 1000 ft., etc., as appropriate,with a C29 plate.

10. RIGHT LANE CLOSED AHEADSign (C20)

The RIGHT LANE CLOSED AHEADsign is used in advance of the pointwhere one lane of a multiple-laneroadway is closed. A LEFT overlayplate (C20A) is available for left laneclosures.

The third line may be altered to read500 ft., 1000 ft., etc., as appropriate,with a C29 plate.

C16

ONE LANEROAD

AHEAD

C1

DETOURAHEAD

C19

ROADCLOSEDAHEAD


5-33

11. FLAGGER Sign (C9A)

The FLAGGER symbol sign shouldbe used before any point where a flaggeris stationed to control traffic. The signshould be used in conjunction withappropriate other warning signs, suchas the ROAD WORK AHEAD (C23)and the PREPARE TO STOP (C36).

The flagging sequence signs shall beremoved, covered, or turned to faceaway from traffic when the flagger isnot at the station.

The sign may be supplemented with anappropriate distance plate (C29) i.e.500 ft., 1000 ft., etc., as appropriate.

12. TWO-WAY TRAFFIC Symbol Sign (W44)

When one direction of travel of anormally divided highway is closed,the TWO-WAY TRAFFIC symbolsign should be used at the beginning ofthe closing and at intervals to reminddrivers that they are on a two-wayhighway with opposing traffic. Thesign should also be used at locationswhere a divided highway illusion maycause motorists to think they are on aone-way roadway when, in fact, theyare on a two-lane, two-way highway.

A typical situation is a constructionsite where a two-lane highway is beingconverted to an expressway or freewayand grading for the full width sectionhas been completed.

13. WORKERS Symbol Sign (C22B)

A WORKERS symbol sign may beused to alert drivers of workers in ornear the roadway. The sign is normallyused on utility type work onconventional low-speed highways. TheC22C WORKERS educational platemay be used below the C22B sign.

C20

CLOSEDAHEAD

RIGHT LANE

W44

C9A


5-34

14. FRESH OIL Sign (C4)

The FRESH OIL sign should be placedto warn drivers that uncovered road oilor resurfacing has rendered thepavement temporarily slippery, and thatsplashing may occur.

15. ROAD MACHINERY AHEAD Sign(C8)

The ROAD MACHINERY AHEADsign may be used to warn of heavyequipment operating in or next to theroadway.

16. SHOULDER WORK AHEAD Sign(C24)

The SHOULDER WORK AHEADsign may be used to warn ofmaintenance, reconstruction, or utilityoperations on the shoulder, where thetraveled way is unobstructed.

17. SURVEY CREW Sign (C25)

The SURVEY CREW sign may beused to warn of survey crews workingin or next to the roadway.

C24

C8

ROADMACHINERY

AHEAD

SHOULDERWORKAHEAD

C22B

C4

FRESHOIL


5-35

1Safety Guide for the Prevention of Radio FrequencyRadiation Hazards in the Use of Commercial ElectricDetonators (Blasting Caps), Safety Library PublicationNo. 20. Institute of Makers of Explosives, 1120 19thSt., N.W. Suite 310, Washington, D.C. 20036-3605.Telephone 202-429-9280.

18. Signs for Blasting Areas

Radio frequency (RF) energy can causethe premature firing of electricdetonators (blasting caps) used intemporary traffic control zones orblasting zones. Drivers must be warnedto turn off mobile radio transmittersand cellular telephones. The Instituteof Makers of Explosives publishesinformation on this hazard andguidelines for safe operations.1

A sequence of signs should be used todirect operators of mobile radioequipment to turn off transmitters in ablasting area. A minimum safe distanceof 300 m should be used for warningsign placement. These signs shall bepredominantly displayed and coveredor removed when there are noexplosives in the area, or the area isotherwise secured.

18a. BLASTING ZONE 1000 FT Sign(C33)

The BLASTING ZONE 1000 FT signshould be used in advance of anywork space where explosives are be-ing used. The TURN OFF 2-WAYRADIOS AND CELLULAR TELE-PHONES and END BLASTINGZONE signs shall be used in sequencewith this sign.

18b.TURN OFF 2-WAY RADIOS ANDCELLULAR TELEPHONES Sign(C34 Revised)

The TURN OFF 2-WAY RADIOSAND CELLULAR TELEPHONESsign should follow the BLASTINGZONE AHEAD sign and is placed atleast 300 m before the beginning ofthe blasting zone.

C25

SURVEYCREW

C33

BLASTINGZONE

1000 FT

C34

TWO-WAY RADIOSTURN OFF

ANDCELLULAR

TELEPHONES


5-36

18c. END BLASTING ZONE Sign (C35)

The END BLASTING ZONE signshall be placed a minimum of 300 mpast the blasting zone, either with orpreceding the (C14) END ROADWORK sign.

19. LOW SHOULDER Sign (C31)

The LOW SHOULDER sign may beused when the elevation between theshoulder and traveled way exceeds 75mm in height and is not protected bya portable barrier.

21. NO CENTER STRIPE Sign (SC16)(Not for State Highway use)

The NO CENTER STRIPE sign maybe used when the work obliterates thecenter stripe. This sign should beplaced at the beginning of the zoneand repeated at 3 km intervals in longzones to remind the motorist. It shouldalso be used at major connections,traffic generators, and/or atappropriate intervals as determinedby the engineer, to advise motoristsentering within the zone.

20. UNEVEN LANES Sign (C41 &C41A)

The UNEVEN LANES sign may beused during operations that create adifference in elevation betweenadjacent lanes.

C41

UNEVENLANES

C41A

C31

LOWSHOULDER

SC16

NOCENTERSTRIPE

C35

ENDBLASTING

ZONE

(Rev. 1)


5-37

22. Other Warning Signs

The signs pictured in Figures 5-8a, 5-8b, and 5-8c may also be used to providesufficient advance warning, either bythemselves or with other advancewarning signs.

Besides the warning signs specificallyrelated to temporary traffic controlzones, several other warning signs,most of which have been standardizedin Section 4-02 of the Caltrans TrafficManual, may apply in these zones.When used in temporary traffic controlzones, warning signs shall have a blacklegend on an orange background exceptfor the W-47 which will always beblack on yellow.

23. Advisory Speed Plate (W6)

In combination with a warning sign, anadvisory speed plate may be used toindicate a recommended safe speedthrough the temporary traffic controlzone. When used with orangetemporary traffic control zone signs,this plate shall have a black legend onan orange background. It shall not beused with any sign other than a warningsign, nor shall it be used alone. Thesign shall be at least 600 mm square insize when used with a sign 900 mmsquare or larger. Except inemergencies, an advisory speed plate(W6) should not be mounted until therecommended speed is determined bythe highway authority. See Figures 5-7a and 7b for regulatory signing.

C. Guide Signs

1. Function and Design of Guide Signs

Guide signs are essential along streetsand roadways to give driversinformation that will help them in themost simple, direct manner possible.The design of guide signs is given inSection 4-04 of the Caltrans TrafficManual.

The following guide signs are requiredat temporary traffic control zones:

a. Standard route markings, wheretemporary route changes arenecessary.

b. Directional signs such as motoristservice signing, recreational andcultural interest area signs, tourist-oriented directional signs (TODS),civil defense signing, and streetname signs. When used with detourrouting, these signs may have ablack legend on an orangebackground.

c. Special information signs relatingto work being done. These signsshall have a black legend on anorange background.

W6

40MPH


5-38

Figure 5-8aWarning Signs Used in Temporary Traffic Control Zones

W1 W2 W3 W5

W11 W15 W17 W18

W25 W26W19 W23

W28 W29 W32 W33

NARROWSROAD

SHOULDERSOFT

NARROWBRIDGE

PAVEMENTENDS

DIP ROUGHROAD


5-39

Figure 5-8bWarning Signs Used in Temporary Traffic Control Zones

W34 W36 W37 W41

W42 W47 W57

W60 W75W58 W59

W81 SW40 C6 C36

12 6ONELANE

BRIDGEBUMP

R R

LANEENDS

MERGELEFT

TRUCKCROSSING

LOOSEGRAVEL

PREPARETO

STOP

(Rev. 1)


5-40

Figure 5-8cWarning Signs Used in Temporary Traffic Control Zones

Fed. No. W5-2a* Fed. No. W9-1* Fed. No. W14-3*

RIGHTLANEENDS

PASSINGNO

ZONE

*Not to be used on State Highways.

(Rev. 1)


5-41

2. Length of Work Sign (C11)

The Length of Work sign should beerected in advance of any temporarytraffic control zone of more than 3.2km in length; it carries the legendROAD WORK NEXT ____ MILES.The distance shall be stated to thenearest whole mile.The C11 sign is also available with themessage STATE HIGHWAYCONSTRUCTION NEXT ____MILES.

3. END CONSTRUCTION/ROADWORK Sign (C13, C14)

The END CONSTRUCTION (ROADWORK) sign should be placed about150 past the work zone. The sign is notrequired if the end of the work zone isobvious to motorists.

4. DETOUR Signs and Markers

The DETOUR ARROW sign (C5)should be used where a detour routehas been established because of theclosing of a street or highway to throughtraffic. The sign should normally bemounted just below the ROADCLOSED (C2, C3, or C3A) sign. TheDETOUR ARROW sign has ahorizontal arrow pointed to the right orleft, as required.

Each detour shall be adequately markedwith standard temporary route markersand destination signs. The DETOURmarker sign (C5A), mounted at the topof a route marker assembly, marks atemporary route that branches from ahighway, bypasses a section closed bya temporary traffic control zone, andrejoins the highway beyond thetemporary traffic control zone.

The DETOUR signs (C5, C5A) shouldbe used for detoured highways, foremergency situations, for periods ofshort durations, or where, overrelatively short distances, traffic maybe guided along the detour and back tothe desired highway. When the detouris a numbered highway, route shieldsshould be included on the signassembly. A street name sign may beplaced above or incorporated in theDETOUR sign to indicate the name ofthe street being detoured.

C11

C14

ENDROAD WORK

ROADCONSTRUCTIONNEXT ___ MILES


5-42

The END DETOUR sign (C7) may beused to indicate that the detour hasended. When the END DETOUR signis used on a numbered highway, thesign should be mounted above a routeshield.

5. PILOT CAR FOLLOW ME Sign(C26)

The PILOT CAR FOLLOW ME signshall be mounted in a conspicuousposition on the rear of a vehicle usedfor guiding one-way traffic through oraround a work space. A flagger shallbe stationed at each end of thecontrolled section of highway. ATRAFFIC CONTROL—WAIT FORPILOT CAR sign (C37) should beused at intersecting approaches to thepilot car controlled section.

5-05.3 Portable Changeable Message Signs

A. Design

Portable Changeable Message Signs(PCMS) are traffic control devices withthe flexibility to display a variety ofmessages to fit the needs of road and streetauthorities. Each message consists of oneor more displays. Portable ChangeableMessage signs are used most frequently onhigh-density, urban freeways, but haveapplications on all types of highways wherehighway alignment, traffic routingproblems or other pertinent conditionsrequire advance warning and information.

C5

C26

C5A

C7

DETOUR

DETOUR

ENDDETOUR

PILOT CARFOLLOW ME


5-43

1. Components: The components of aPCMS should include message signpanel, control systems, power source,and mounting and transportingequipment.

a. Message Sign Panel

PCMS cannot always conform tothe exact sign shape, color, anddimensions specified in thesestandards. PCMS should subscribeto the principles established in themanual, and to the extentpracticable, with the design (i.e.,color, letter size and shape, andborders) and applicationsprescribed herein. The messagesign panel can vary in size and mayconsist of one, two, or three lines.High-density urban freewaystypically use three lines of eightcharacters per line. Each charactermodule shall use, as a minimum, afive wide-pixel by seven high-pixelmatrix. The front face of the signshould be covered with a protectivematerial. Element colors forwarning messages should be blackon a yellow or orange background;for guide messages, white on agreen background or black on anorange background; and forregulatory messages, black on awhite background. Color reversalsare also acceptable.

The signs should be visible from460 m under ideal day and nightconditions. Each sign messageshould be legible from all lanes,from the sign up to a minimum of

230 m. In the field, the PCMSshould be sited and aligned tooptimize driver perception andunderstanding. The message panelshould have adjustable flash rates,so that the entire message can beread at least twice at the postedspeed, the off-peak 85th percentilespeed prior to work starting, or theanticipated operating speed.

Under low light level conditions,the sign shall automatically adjustits light source so as to meet thelegibility requirements and notimpair the drivers’ vision.

b. Control System

The control system shall includethe following features:

• A display screen upon whichmessages can be reviewedbefore display on the messagesign.

• A capability to provide anautomatic programmed defaultmessage if power failureoccurs.

• A backup battery to maintainmemory when power isunavailable.

c. Power Source

The PCMS shall be equipped witha power source and a battery back-up to provide continuing operationwhen failure of the primary powersource occurs.


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d. Mounting

The mounting of the PCMS shallbe such that the bottom of themessage sign panel shall be aminimum of 2.1 m above theroadway when it is in the operatingmode.

B. Application.

PCMS have a wide variety of applicationsin temporary traffic control zones,including roadway or ramp closures,accident or emergency incidentmanagement, width restrictioninformation, advisories on roadworkscheduling, traffic management anddiversion, warning of adverse conditions,and operation control. PCMS should beused with conventional signs, pavementmarkings, and lighting.

The primary purpose of PCMS intemporary traffic control zones is to advisethe driver of •traffic and routing situations.Some typical applications include thefollowing:

• Where speed of traffic is expected todrop substantially

• Where significant queuing and delaysare expected

• Where adverse environmentalconditions are present

• Where there are severe changes inalignment or surface conditions

• To provide advance notice of ramp,lane, or roadway closures

• For accident or incident management

PCMS should be placed to be visible fromat least 450 m under both day and nightconditions. Placement in advance of thetemporary traffic control zone or incidentshould, as much as possible, take intoaccount the following factors:

• PCMS will typically be placed inadvance of any other temporary trafficcontrol zone signing and should notreplace any required signing.

• Where used for route diversion, PCMSshould be placed far enough in advanceof the work site to allow traffic ampleopportunity to exit the affectedhighway.

• PCMS are normally placed on theshoulder of the roadway. However, ifpractical, placement further from thetraveled lane is desirable.

• When two signs are needed to commu-nicate multiple messages, they shouldbe placed on the same side of the road-way, separated by at least 300 m.

PCMS messages should be readilyunderstood by drivers and thus will allowthem adequate time to react. Messagesshould be designed taking into account thefollowing factors:

• No more than two displays should beused within any message cycle.

• Each display should convey a singlethought.

• Messages should be as brief as possible.


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• When abbreviations are used, theyshould be easily understood.

• The entire message cycle should bereadable at least twice at the postedspeed, the off-peak 85th percentilespeed prior to work starting, or theanticipated operating speed.

• Messages shall not scroll horizontallyor vertically across the face of the sign.

5-05.4 Flashing Arrow Signs (Arrow Display)

A Flashing Arrow Sign (FAS-arrow display)is a sign with a matrix of elements. The matrix,capable of either flashing or sequential displays, isintended to provide additional warning anddirectional information to assist in merging andcontrolling traffic through or around a temporarytraffic control zone. An arrow display should beused in combination with appropriate signs,barricades, or other traffic control devices.

A. Flashing Arrow Sign Specifications

FAS shall meet the size and otherspecifications of Figure 5-9. A PCMSmay be used to simulate an arrow display.

Type A arrow displays are appropriate foruse on low-speed urban streets. Type II areappropriate for intermediate-speedfacilities and for maintenance or mobileoperations on high-speed roadways. TypeI arrow displays are intended to be used onhigh-speed, high-volume traffic controlprojects.

FAS shall be rectangular, of solidappearance, and finished in non-reflectiveblack. The panel shall be mounted on avehicle, a trailer, or other suitable support.

A vehicle-mounted panel should beprovided with remote controls. Minimummounting height should be 2.1 m from theroadway to the bottom of the panel, excepton vehicle-mounted panels, which shouldbe as high as practicable.

FAS shall have the following modeselections:

• A Flashing Arrow, Sequential Arrow,or Sequential Arrowhead (Chevron)mode

• Flashing Double Arrow mode

• Flashing Caution mode

FAS elements shall be capable of aminimum 50 percent dimming from theirfull-rated lamp voltage. Full lamp voltageshould be used for day, and dimmed modeshall be used for night.

FAS shall have suitable elements capableof the various operating modes. If anarrow panel consisting of a bulb matrix isused, the elements should be recess-mounted or equipped with an upper hoodof not less than 180 degrees. The colorpresented by the elements shall be yellow.

Minimum element "on time" shall be 50percent for the flashing mode and equalintervals of 25 percent for each sequentialphase. The flashing rate shall be no fewerthan 25 nor more than 40 flashes per minute.

B. Flashing Arrow Sign Application.

A FAS in the arrow or chevron mode maybe used for stationary or moving laneclosures. The caution mode shall be used


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Figure 5-9Flashing Arrow Sign Specifications

Panel Display*(Right shown; left similar)

Move/Merge Right

Move/Merge Right

Move/Merge Right

Operating Mode

At least one of the three following modes shall be provided:

Flashing Arrow

Sequential Arrow

Sequential Chevron

*Element layout for Type I FAS shown.

I.

Move/Merge Right or Left

The following mode shall be provided:

Flashing Double Arrow

2.

Caution

The following mode shall be provided:

Flashing Caution

3.

or

PanelTypes

AIII

Minimum Size(mm)

1200 x 6001800 x 9002400 x 1200

Minimum LegibilityDistance (km)

0.81.21.6

Minimum Numberof Elements

121315

(Rev. 1)


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only for shoulder work, blocking theshoulder, roadside work near the shoulder,or work within a closed lane.

For a stationary lane closing, the FASshould be located on the shoulder at thebeginning of the taper.

Where the shoulder is narrow, the FASshould be located in the closed lane. If theyare used when multiple lanes are closed intandem, the preferred position foradditional arrow displays is in the closedlane at the start of the merge taper. Undervarious situations, such as for narrowshoulders, placement may be in the middleor at the end of the merge taper but alwaysbehind the channelizers. The FAS shall belocated behind any channelizing devicesused to transition traffic from the closedlane.

For mobile operations where a lane isclosed, the FAS arrow display should belocated to provide adequate separation fromthe work operation to allow for appropriatereaction by approaching drivers. A vehicledisplaying an arrow display shall beequipped with appropriate signing and/orlighting.

An arrow display shall not be used on atwo-lane, two-way roadway for temporaryone-lane operation, or within a closed lane.

An arrow display shall not be used tolaterally shift, or divert, lanes of trafficbecause it may cause unnecessary lanechanging. For stationary lane closuresonly one arrow display shall be used foreach lane closed; it is normally placed atthe beginning of the taper for the closedlane, where traffic must evacuate that lane.

For moving lane closures the arrow displayis also used on the advance warning vehicle(in the shoulder area), to reinforce the needfor motorists to evacuate the lane(s) closedahead in which the work vehicles areoccupying.

5-05.5 High-Level Warning Devices

The high-level warning device (flag tree) maysupplement other traffic control devices intemporary traffic control zones. It is designed tobe seen over the top of vehicles. A typical high-level warning device is shown in Figure 5-6.

A high-level warning device shall consist of aminimum of two flags with or without a Type B,high-intensity, flashing warning light. The distancefrom the roadway to the bottom of the lens of thelight and to the lowest point of the flag materialshall be no less than 2.4 m. The flags shall be 400mm square or larger and shall be orange orfluorescent versions of orange in color. Anappropriate warning sign may be mounted belowthe flags.

High-level warning devices are mostcommonly used in urban high-density trafficsituations to warn motorists of short-termoperations.

5-05.6 Channelizing Devices

A. General

The function of channelizing devices is towarn and alert drivers of conditions createdby work activities in or near the traveledway, to protect workers in the temporarytraffic control zone, and to guide driversand pedestrians. Channelizing devicesinclude, but are not limited to, cones,portable delineators, drums, barricades,temporary raised islands, and barriers.


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Devices used for channelization shouldprovide for smooth and gradual trafficmovement from one lane to another, ontoa bypass or detour, or to reduce the widthof the traveled way. They may also be usedto separate traffic from the work space,pavement drop-offs, pedestrian paths, oropposing directions of traffic.

Channelizing devices should beconstructed and ballasted to perform in apredictable manner when inadvertentlystruck by a vehicle. If struck, they shouldyield or break away, and fragments orother debris from the device should notpenetrate the passenger compartment ofthe vehicle or become a flying object whichcould strike workers or pedestrians in theimmediate area.

Spacing of channelizing devices shouldnot exceed a distance in m equal to 0.2 xkm/h (speed) when used for the taperchannelization, and a distance in m of 0.4x km/h (speed) when used for tangentchannelization.

Warning lights on channelizing devicesshould be considered in fog or snow areas,severe roadway curvature, and unusuallycluttered environments. Flashing warninglights may be placed on channelizingdevices used singly or in groups to mark aspot condition. Warning lights onchannelizing devices used in a series shallbe steady-burn.

The retroreflective material used onchannelizing devices shall have a smooth,sealed outer surface.

Channelizing devices are elements in atotal system of traffic control devices foruse in temporary traffic control zones.These elements shall be preceded by asubsystem of warning devices that areadequate in size, number, and placementfor the type of highway on which the workis to take place. Standard designs ofchannelizing devices are shown in Figure5-10.

The name and telephone number of theagency, contractor, or supplier may beshown on the non-retroreflective surfaceof all channelizing devices. The lettersand numbers shall be a non-retroreflectivecolor and not over 50 mm in height.

Particular attention should be given toassuring that channelizing devices aremaintained and kept clean, visible, andproperly positioned at all times. Devicesshall be replaced that are damaged andhave lost a significant amount of theirretroreflectivity and effectiveness.

B. Cones

1. Design

Cones shall be predominantly orange,fluorescent red-orange, or fluorescentyellow-orange, not less than 450 mmin height, and shall be made of a materialthat can be struck without damagingvehicles on impact. Cones shall be aminimum of 700 mm in height whenthey are used on freeways and otherhigh-speed highways, on all highwaysduring nighttime, and all Statehighways, or whenever moreconspicuous guidance is needed.

(Rev. 1)


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Figure 5-10Barricades and Channelizing Devices

*Nominal lumber dimensions are satisfactory for barricade rail width dimensions.**Rail stripe widths shall be 150 mm except where rail lengths are less than 900 mm, then 100 mm wide stripes may be used. The sides of barricades facing traffic shall have white and orange retroreflective rail faces.

600 mmMinimum

200 mm to300 mm*

900 mmMinimum

45 Deg.

Type I Barricade**

WarningLight

(Optional)

200 mm to300 mm*

900 mmMinimum

45 Deg.

600 mmMinimum

Type II Barricade**

1500 mmMinimum

45 Deg.

1200 mmMinimum

Type III Barricade**

450 mmMinimum

900 mm

100 mm to150 mm

FacingTraffic

Drum

900 mmMinimum*

88 mm Min.

75 mm x 300 mmWhite Retroreflective

Sheeting

56 mm Min.

Channelizer

*700 mm where speedsare 65 km/h or less

200 mm to300 mm*

OrangeRetroreflective

Bands

WhiteRetroreflective

Bands

700 mm

150 mm

100 mm

75 mm - 100 mm

50 mm450 mm

Night and/or FreewayHigh Speed Roadway(70 km/h and more)

Day and LowSpeed Roadway

(65 km/h and less)

Cones

White Retroreflective Bands or a325 mm Single Sleeve may be used.

700 mm

50 mm

75 mm

50 mm - 150 mm

75 mm450 mm

WhiteRetroreflective

Bands

Night and/or FreewayHigh Speed Roadway(70 km/h and more)

Day and LowSpeed Roadway

(65 km/h and less)

Tubular Markers

56 mm Min.

56 mm Min.

(Rev. 1)


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For nighttime use, cones shall beretroreflective or equipped withlighting devices for maximumvisibility. Retroreflection of 700 mmor larger cones shall be provided by a325 mm band (sleeve), or a white band150 mm wide, no more than 75 to 100mm from the top of the cone, and anadditional 100 mm wide white band aminimum of 50 mm below the 150 mmband.

2. Application

Traffic cones are used to channelizetraffic, divide opposing traffic lanes,divide traffic lanes when two or morelanes are kept open in the samedirection, and delineate short-durationmaintenance and utility work.

Steps should be taken to ensure thatcones will not be blown over ordisplaced by wind or moving traffic.Cones can be doubled up to increasetheir weight. Some cones areconstructed with bases that can be filledwith ballast. Others have specialweighted bases, or weighted rings thatcan be dropped over the cones and ontothe base to provide added stability.Ballast, however, should not presentany safety concerns if the cones areinadvertently struck.

C. Portable Delineators (Tubular Markers)

1. Design

Portable delineators shall bepredominantly orange, not less than450 mm high, minimum 56 mm widewhen facing traffic, and made of a

material that can be struck withoutdamaging impacting vehicles. Portabledelineators shall be a minimum of 700mm high when used on freeways andother high-speed highways, on allhighways during nighttime, orwhenever more conspicuous guidanceis needed.

For nighttime use, portable delineatorsshall be retroreflective. Retroreflectionof portable delineators shall be providedby two 75 mm wide white bands placeda maximum of 50 mm from the top,with a maximum of 150 mm betweenthe bands. The bands shall be visible at300 m at night when illuminated bystandard high beam headlights.

2. Application

Portable delineators have less visiblearea than other devices and should beused only where space restrictions donot allow for the use of other morevisible devices. They may be usedeffectively to divide opposing lanes oftraffic, divide traffic lanes when two ormore lanes are kept open in the samedirection, and delineate edge ofpavement dropoff where spacelimitations do not allow the use oflarger devices.

Steps should be taken to assure thatportable delineators will not be blownover or displaced by traffic by eitheraffixing them to the pavement withanchor bolts or adhesive, usingweighted bases, or weights that can bedropped over the portable delineatorsand onto the base to provide addedstability. Ballast, however, should not

(Rev. 1)


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be allowed to present any safetyconcerns if the delineators areinadvertently struck. If a noncylindricaldevice is used, and it could be displayedwith a width less than the minimumfacing traffic, it shall be attached to thepavement to ensure that the widthfacing traffic meets the minimumrequirements.

D. Channelizers (Permanent type, flexiblepost)

1. Design

Channelizers are implanted in theground or affixed (i.e. epoxied) to thepavement, and are not susceptible todisplacement, and are capable ofnormally withstanding numerousvehicular impacts. The height shall be900 mm minimum (700 mm wherespeeds are 65 km/h or less), the widthof the post shall be 56 mm minimumand the color predominantly orange.The 75 mm x 300 mm minimumretroreflective unit shall be white, andshall be visible at 300 m at night whenilluminated by standard high beamheadlights. (See Chapter 6 of theCaltrans Traffic Manual for otherdetails and requirements.)

2. Application

Channelizers are generally used inseries to create a visual fence/barrier,to provide additional guidance and/orrestriction to traffic. They also may beused in lieu of cones, portabledelineators, or drums, to channelizetraffic, divide opposing lanes of traffic,etc.

E. Drums

1. Design

Drums used for traffic warning orchannelization shall be constructed oflow-density polyethylene material andshall be flexible or collapsible uponimpact by a vehicle. They shall bedesigned to resist overturning by meansof a weighted base that will separatefrom the drum when impacted by avehicle. The base shall be of sufficientweight to maintain the drum in positionand upright. Ballast, if used, shall beeither sand or water contained withinthe base, or an external ring(s) placedover (and around) the drum, resting onthe base. The drum base and/or externalballast ring(s) shall not exceed 100mm in height, and drum rings shall notexceed 950 mm maximum in diameter.Steel drums shall not be used.

The drum body shall be of a fluorescentorange or predominately orange color.Drums shall be a minimum of 900 mmin height above the traveled way- andhave at least a 450 mm minimum widththroughout the 900 mm minimumheight.

The markings on drums shall behorizontal, circumferential, alternatingorange and white retroreflective bands100 to 150 mm wide. Each drum shallhave a minimum of two orange andtwo white bands. Any non-retroreflectorized spaces between the bandsshall not exceed 50 mm wide. Thebands shall be visible at 300 m at nightwhen illuminated by standard highbeam headlights.

(Rev. 1)


5-52

2. Application.

Drums are most commonly used tochannelize or delineate traffic flow butmay also be used singly or in groups tomark specific locations. Drums arehighly visible and have good targetvalue, giving the appearance of beingformidable obstacles and, therefore,command the respect of drivers. Theyare portable enough to be shifted fromplace to place within a temporary trafficcontrol project to accommodatechanging conditions but are generallyused in situations where they willremain in place for a prolonged period.

Drums should not be weighted withsand, water, or any material to an extentthat would make them a problem formotorists, pedestrians, or workers.When they are used in regionssusceptible to freezing, they shouldhave drainage holes in the bottom sowater will not accumulate and freeze.Ballast shall not be placed on top of thedrum.

F. Barricades.

1. Design.

Barricades are portable or fixed deviceshaving from one to three rails withappropriate markings. They are usedto control traffic by closing orrestricting all, or a portion, of the right-of-way.

Barricades shall be of three types: TypeI, Type II, or Type III.

Stripes on barricade rails shall bealternating orange and whiteretroreflective stripes slopingdownward at an angle of 45 degrees.The stripes shall be 150 mm wide,except where rail lengths are less than900 mm, then 100 mm wide stripesmay be used. The minimum rail lengthis 600 mm. Barricades used onexpressways, freeways, and other high-speed roadways shall have a minimumof 0.17 m2 of retroreflective area facingtraffic.

Barricade rails should be supported ina manner that will allow them to beseen by motorists and provide a stablesupport not easily blown over by thewind or traffic. The support for TypeI barricades may include otherunstriped horizontal panels necessaryto provide stability.

Barricades are located adjacent totraffic and, therefore, are subject toimpact by errant vehicles. Because oftheir vulnerable position and the objectthey become to vehicles, they shouldbe constructed of lightweight materialsand have no rigid stay bracing for A-frame designs.

On high-speed highways or in othersituations where barricades may besusceptible to overturning in the wind,sandbags should be used for ballasting.Sandbags may be placed on lower partsof the frame or stays to provide therequired ballast, but shall not be placedon top of any striped rail. Barricadesshall not be ballasted by heavy objectssuch as rocks or chunks of concrete.

(Rev. 1)


5-53

Owner identification shall not beimprinted on the face of anyretroreflectorized rail, but may beprinted elsewhere.

2. Application

Type I or Type II barricades may beused singly or in groups to mark aspecific object. They may also be usedas channelizing devices when they areintended to provide additionalemphasis in areas where workers arepresent. Type I barricades normallywould be used on conventional roadsor urban streets and arterials. Type IIbarricades have more retroreflectivearea and are intended for use onexpressways and freeways, or otherhigh-speed roadways.

Type III barricades used at a roadclosure may extend completely acrossa roadway or from curb to curb. Whereprovision is made for access ofauthorized equipment and vehicles, theresponsibility for the Type IIIbarricades should be assigned to aperson to ensure proper closure at theend of each work day.

When a highway is legally closed butaccess must still be allowed for localtraffic, Type III barricades should notbe extended completely across aroadway. A sign with the appropriatelegend concerning permissible use bylocal traffic should be mounted on thebarricade(s). (See Section 5-05.2.A.5.)

Signs may be erected on barricades,particularly those of the fixed type.

The ROAD CLOSED and DetourArrow signs, and the Large Arrowwarning signs, for example, can bemounted effectively on or above a TypeIII barricade(s) that closes the roadway.The bottom of signs mounted onbarricades shall be no less that 0.3 mabove the traveled way.

G. Portable Barriers

The need for portable barriers should bedetermined by engineering analysis andthe protective requirements of the location,not the channelizing needs. They shouldbe designed in accordance CaltransStandard Plans and Specifications.

When serving the additional function ofchannelizing traffic, the barrier taper shallmeet standard channelizing taper lengths.The channelizing barrier shall be supple-mented by standard delineators,channelizing devices, or pavement mark-ings. Channelizing barriers should not beused for a merging taper except in low-speed urban areas. See page 5-60 foraddition Portable Barriers information anduse.

H. Temporary Raised Islands

Temporary raised islands should only beused on roadways with speeds of 70 km/hor less except when recommended by anengineering study.

Temporary raised islands, not to exceed100 mm in height, may be used tosupplement channelizing devices andpavement markings to separate traffic flowsin two-lane, two-way operations(TLTWO.) Pavement edge lines may be


5-54

placed on the island itself. Islands mayalso have application in other than TLTWOwhere physical separation of traffic in thetemporary traffic control zone is desired.

One type of temporary raised island is 100mm high by 450 mm wide and has roundedor chamfered corners. They may beconstructed of Portland cement concreteor bituminous concrete.

I. Other Channelizing Devices

Channelizing devices, other than thosespecified above, may be required for specialsituations based on an engineering study.Such devices should conform to the generalsize, color, stripe pattern, retroreflection,and placement characteristics establishedfor standard devices.

5-05.7 Markings

A. Pavement Marking Applications

Adequate pavement markings shall bemaintained along paved streets andhighways in temporary traffic controlzones. Conflicting markings shall becompletely removed as identifiablepavement markings under day or night,wet or dry conditions. The work should beplanned and staged to provide the bestpossible conditions for the placement andremoval of the pavement markings.

It is intended, to the extent possible, thatmotorists be provided markings within awork zone comparable to the markingsnormally maintained along adjacentroadways, particularly at either end of thework zone. The following guidelines set

forth the level of markings and delineationfor various work zone situations.

1. All markings shall be in accordancewith chapter 6 of the Caltrans TrafficManual, except as indicated underSection 5-05.7B (Interim Markings)of this manual.

2. Markings shall be maintained in long-term (more than two weeks) stationarywork zones and shall match and meetthe markings in place at both ends ofthe work zone.

3. Markings should be provided in short-term (not more than two weeks)stationary work zones, as provided forunder Section 5-05.7B (InterimMarkings) of this manual.

4. Markings shall be placed along theentire length of any surfaced detour ortemporary roadway, before such detouror roadway is opened to traffic.

5. Centerlines and lanelines should beplaced, replaced, or delineated whereappropriate before the roadway isopened to traffic.

6. In any work zone where it is notpractical to provide a clear path bymarkings, appropriate warning signs,channelizing devices, and delineationshall be used to indicate the requiredvehicle paths.

All markings and devices used to delineatevehicle and pedestrian paths shall becarefully reviewed during daytime andnighttime periods to assure they lead driversor pedestrians in the intended path.


5-55

Proper pavement marking obliterationleaves a minimum of pavement scars andcompletely removes old markingmaterials. Obliterated markings shall beunidentifiable as pavement markings underday or night, wet or dry conditions.Overlaying existing stripes with black paintor asphalt does not meet the requirementsof covering, removal, or obliteration;however, the use of removable,nonreflective, preformed tape is permittedwhere markings need to be coveredtemporarily.

B. Interim Markings

Delineation in construction andmaintenance zones is intended to be aguide to indicate the alignment of theroadway and outlines the required vehiclepath through these areas.

Delineators are reflector units capable ofclearly reflecting light under normalatmospheric conditions from a distance of300 m when illuminated by the upper beamof standard automobile lights.

Interim pavement markings are those thatmay be used until installation of pavementmarkings that meet the standards forpermanent pavement markings. Interimpavement markings, as described below,shall not be left in place for more than twoweeks (short term). Interim pavementmarkings, to remain in place for more thantwo weeks (long-term), shall conform tothe requirements for permanent markings.(See Chapter 6 of the Caltrans TrafficManual.)

1. Temporary lanelines and/or centerlinesshall consist of retroreflectorized linesapproximately 600 mm long, 100 mmwide, spaced approximately 7.3 mapart. Day/night raised retro-reflectorized pavement markers,approved by the California Departmentof Transportation (Caltrans), may beused in lieu of 600 mm lines, spacedapproximately 7.3 m apart.

2. Right edgelines should not be simulatedwith dashes or pavement markersbecause they could confuse motorists;however, portable delineators,permanent type delineators, etc., maybe used where it is considered desirableto enhance the edge of traveled waydue to curvilinear alignment, narrowingpavement, etc.

3. Locations on two-lane conventionalhighways where no-passing zonecenterline delineation has beenobliterated shall be posted with a signpackage consisting of a "ROADCONSTRUCTION/WORK AHEAD"sign(s) C18/C23 and a "DO NOTPASS" sign R63 The R63 sign shouldbe posted at 600 m intervals throughoutthe extended no-pass zone. A "PASSWITH CARE" sign R64 should also beplaced at the end of the zone.

C. Raised Pavement Markers.

Raised pavement markers should beconsidered for use along surfaced detoursor temporary roadways, and other changedor new travel way alignments, because ofthe need to accentuate changed travel pathsand their wet-weather performancecapabilities.


5-56

Non-retroreflective raised pavementmarkers, supplemented by retroreflectivemarkers, may be used to simulate paintedlines as shown in Chapter 6 of the CaltransTraffic Manual.

D. Delineators

Delineators (retroreflective units) may beused in work zones to indicate the alignmentof the roadway through the temporarytraffic control zone. Delineators, whenused, shall be used in combination with, orbe supplemental to, other traffic controldevices.

Delineators shall be mounted on suitablesupports about 1.2 meters above the nearroadway edge, placed 0.6 to 1.8 m outsidethe outer edge of the shoulder. They shallbe 75 mm x 300 mm minimum and thecolor shall be the same as the color of theedgeline; white on the right side of traffic,and yellow on the left. Delineators shall bevisible at 300 m at night when illuminatedby standard high beam headlights. Spacingalong roadway tangents and curves shouldbe as set forth in Section 6-04 of the CaltransTraffic Manual.

5-05.8 Lighting Devices

A. Function

Temporary traffic control activities oftencreate conditions on or near the traveledway that are particularly unexpected atnight, when drivers’ visibility is sharplyreduced. It is often desirable and necessaryto supplement retroreflectorized signs,barriers, and channelizing devices withlighting devices.

Four types of lighting devices arecommonly used: floodlights, flashingyellow beacons, steady-burning electriclamps, and warning lights.

In work zones where a study indicates anighttime collision problem can becorrected with area illumination,consideration may be given to providingroadway lighting.

B. Floodlights

In temporary traffic control zones,floodlights have a limited but importantapplication. Temporary traffic controlactivities on urban freeways mustfrequently be conducted during nighttimeperiods when traffic volumes are lower.Sometimes, large temporary traffic controlcontracts are also operated on double shift,requiring night work. When nighttimework is required for these or similar typesof projects, floodlights should be used toilluminate flagger stations, equipmentcrossings, and other areas where existinglight is not adequate for the work to beperformed.

In no case shall floodlighting be permittedto create a disabling glare for drivers. Theadequacy of the floodlight placement, andelimination of potential glare, can best bedetermined by driving through andobserving the floodlighted area from eachdirection on the main roadway after initialfloodlight setup.

Construction and maintenance activitieson urban freeways with high-volume, high-density traffic conditions are frequentlyconducted during nighttime periods (with


5-57

low traffic volumes). Floodlighting of thework site is important because the workersneed to see what they are doing, and becausethe workers and the work space needs to beseen by passing drivers.

C. Portable Flashing Beacons

Portable flashing beacons may be usednear points of potential conflict as a meansof calling motorists’ attention to theselocations. When used, they shouldnormally be operated 24 hours a day.

The beacons may be operated singly or ingroups. Each flashing beacon unit shallconsist of a lighting unit, a flasher unit, astandard, a power source, and a base. Powermay be provided by batteries or A.C.electricity. Portable units should be self-contained, which can be delivered to thejob site and be placed in immediateoperation.

The beacon lens shall have a visiblediameter of 300 mm and shall conform toState standards for signal lenses, and thelighting unit shall have a hood and backplateor other suitable means of providingadequate contrast.

The flasher unit shall provide 50 to 60flashes per minute with 250 to 350milliseconds dwell time. The lamp shallprovide a light output equivalent to a 25watt incandescent lamp.

The mounting height shall be between 1.8and 3 m, measured from the bottom of thebase to the center of the lens.

During normal daytime maintenanceoperations, the functions of flashing

beacons are adequately provided byrotating dome or strobe lights on vehicles.However, flashing beacons may beinstalled at locations where work activitiesrequire an obstruction(s) to remain in theroadway at night. (See Section 9-05"Flashing Beacons" of the Caltrans TrafficManual.)

D. Steady-Burning Electric Lamps

As used herein, steady-burning electriclamps shall mean a series of low-wattageyellow electric lamps. They may be usedto mark obstructions, but they are generallyless effective than flashing lights for suchuse because of their attention-getting effect.However, if lights are needed to delineatethe traveled way through and aroundobstructions in a temporary traffic controlzone, the delineation shall be accomplishedby steady-burning lamps.

Steady-burning lamps, placed in a line onappropriate channelizing devices, areeffective in delineating the proper vehiclepath through temporary traffic controlzones that require changing patterns oftraffic movement. Steady-burning lampsare also used on detours, on lane closures,when the roadway alignment changes intapers, and other situations where theheadlights do not provide retroreflectionto delineate the intended vehicle path.

The application of these devices duringmaintenance work is infrequent due to thegenerally short-term nature of the work. Atype of maintenance activity where steady-burning lamps could be used is removaland replacement of a part of a bridge deck.The lamps could be mounted on barricadesand help channel traffic around the workspace.

(Rev. 1)


5-58

E. Warning Lights

The light weight and portability of warninglights are advantages that make thesedevices useful as supplements to the retro-reflectorization on hazard warning devices.The flashing lights are effective in attractinga driver’s attention.

As used herein, warning lights are portable,lens-directed, enclosed lights. The colorof the light emitted shall be yellow. Theymay be used in either a steady-burn orflashing mode. Warning lights shall be inaccordance with the current ITE PurchaseSpecification for Flashing and Steady-BurnWarning Lights1.

Warning lights shall have a minimummounting height of 750 mm to the bottomof the lens. Type A low-intensity flashingwarning lights are most commonlymounted on barricades, drums, or advancewarning signs, and are intended to warndrivers that they are approaching, or in, anarea of potential conflict.

Type B high-intensity flashing warninglights are normally mounted on advancewarning signs or on independent supports.Site conditions within temporary trafficcontrol zones may require that the lights beeffective in daylight as well as dark. Theyare designed to operate 24 hours per day.Flashers shall not be used for delineation,as they would tend to obscure the desiredvehicle path.

Type C steady-burn lights are intended tobe used to delineate the edge of the traveledway on detour curves, on lane changes, onlane closures, and on other similarconditions.

Type A low intensity flashing warninglights and Type C steady-burn warninglights shall be maintained so as to be visibleon a clear night from a distance of 900 m.Type B high intensity flashing warninglights shall be maintained so as to be visibleon a sunny day, when viewed without thesun directly on or behind the device, froma distance of 300 m.

5-05.9 Other Devices

A. Crash Cushions

Crash cushions (also known as impactenergy attenuators) are systems thatmitigate the effects of errant vehicles thatstrike objects, either by decelerating thevehicle to a stop when hit head-on, or byredirecting the errant vehicle. Crashcushions in temporary traffic control zonesprotect motorists from the exposed ends ofbarriers, and other fixed objects. Twotypes of crash cushions used in temporarytraffic control zones are roadside crashcushions and truck-mounted crash cushions(TMCC). Information about designs andtypes of crash cushions currently approvedfor use on State highways is available fromCaltrans' Division of Traffic Operations inSacramento.

1Included in the Equipment and Material Standards ofthe Institute of Transportation Engineers PublicationNo. ST 017; 525 School Street, S.W., Suite 410,Washington, D.C. 20024.Telephone: 202-554-8050.


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Crash cushions must pass acceptableperformance testing and be designed toensure performance to minimize injury tomotorists or redirect errant vehicles.Periodic inspection of these devices isnecessary to assure that they function asintended throughout their useful life, orthat they undergo prompt repair/replacement if hit or damaged.

1. Roadside Crash Cushions

Roadside crash cushions are used inthe same manner as permanent highwayinstallations to protect motorists fromthe exposed ends of barriers, and otherfixed objects. Two types of stationarycushions are commonly used and mustbe designed for the specific applicationintended as follows:

a. Redirective Type

The redirective type is anassembled unit designed to absorbhead-on vehicle impacts andtelescope toward the rear; also itmay be capable of absorbing sideimpacts by redirecting a vehicle.

Redirective types normally are usedwhen the exposed object is narrow,or when space for a non-redirectivetype is unavailable, such as onsurface streets near adjacentintersecting roadways. The cushionwidth must be wider than the objectit is shadowing, but as close to theobject width as possible, to preventits lateral intrusion into the trafficlanes.

b. Non-redirective Type

The non-redirective type may bestruck head-on, and may be thesand-filled plastic barrel system orother acceptable energy-absorbingdevice designed to stop errantvehicles.

Non-redirective crash cushionsmust be checked frequently forvehicle impacts because, once hit,they may not function as designedfor a second hit. When sand-filledbarrels are fractured, the sand isscattered, site cleanup is needed,and the cushion must be restoredwith replacement barrels and sand.

2. Truck-Mounted Crash Cushions

Trucks or trailers are often used asprotective vehicles to protect workersor work equipment from errantvehicles. These protective vehiclesare normally equipped with flashingarrows, changeable message signs, and/or flashers, and must be locatedproperly in advance of the workersand/or equipment they are protecting.

Truck-Mounted Crash Cushions(TMCC) are capable of absorbing theimpact of errant vehicles can beattached to the rear of these protectivevehicles to reduce the severity of rear-end crashes. There are a variety ofTMCC designs available.

The protective truck must be positioneda sufficient distance in front (upstream)of the workers or equipment being


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protected to allow for appropriatevehicle roll-ahead, but not so far thaterrant vehicles will travel around thevehicle and strike the workers/equipment. The cushion should be inthe full down-and-locked position. Forstationary operations, the truck’sparking brake should be set and, whenpossible, the front wheels turned awayfrom the work site and traffic.

B. Portable Barriers

Portable barriers are designed to preventvehicles from penetrating work zonesbehind the barrier while minimizingoccupant and worker injuries. They mayalso be used to separate two-way traffic.These devices may be constructed ofconcrete, metal, or any material that canphysically prevent vehicular penetration.

Portable barriers may serve to channelizetraffic. Use for a specific project should bedetermined by engineering analysis.However, the protective requirements ofthe work zone, not the channelizing needs,govern the use of portable barriers. Whenserving the additional function ofchannelizing traffic, portable barriersshould be of a light color for increasedvisibility. For nighttime visibility, barriersshall be supplemented with standarddelineation, markings, or channelizingdevices. More specific information on theuse of portable barriers and crash cushionscan be obtained from the Caltrans StandardPlans and Standard Specifications.

Warning lights may be mounted oncontinuous barriers. On each side of the

roadway only the first two yellow warninglights at the start of a continuous barriershould be Type A flashing. Subsequentwarning lights on the barrier shall be TypeC yellow, steady-burning for channel-ization.

The effect of striking the ends of barriersshould be mitigated by use of crash cushionsor by flaring the ends of barriers away fromthe traveled way. See page 5-53 foradditional information.

C. Temporary or Portable Traffic Signals

Temporary or portable traffic signals canbe used for special applications to controltraffic flow at temporary traffic controlzones. These applications include ahighway intersection with a temporary haulroad or equipment crossing, and temporarytraffic control zones with alternate one-way traffic flow, such as bridgeconstruction.

All traffic signal and control equipmentshall meet the standards and specificationsprescribed in Chapter 9 of the CaltransTraffic Manual and/or the Standard Plansand Special Provisions.

One-way traffic flow requires an all-redinterval of sufficient duration for traffic toclear the portion of the temporary trafficcontrol zone controlled by the trafficsignals. Temporary or portable trafficsignals shall be constructed such as toavoid the display of conflicting signals ateach end of the temporary traffic controlzone.

(Rev. 1)


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D. Rumble Strips

Rumble strips are transverse strips of rough-textured surface used to supplementstandard or conventional traffic controldevices. Rumble strips may be used toalert drivers of a change in traffic conditionsor geometrics or to bring the driver’sattention to other warning devices. Theyprovide a vibratory and audible warningthat supplements visual stimuli.

Rumble strips are not suitable as a ridingsurface for bicycles and motorcycles.Where cyclists are permitted, provisionsshould be made to allow passage throughor around the rumble strips.

A rumble strip may consist of raised stripsor depressed grooves. The cross-sectionmay be rectangular, domed, or trapezoidalin shape. The strips or grooves should beplaced transverse to the direction of traffic.The intervals between rumble strip padsshould be reduced as the distance to thecondition diminishes, to create a sensationof acceleration for motorists.

The first rumble strip pad should be placedbefore the advance warning devices. Thelast rumble strip pad should be placed aminimum of 80 m in advance of the trafficcondition or stop position. Rumble strippads should not be placed on shorthorizontal or vertical curves where loss ofvehicle control could occur because of theaction of the rumble strips on a vehicle’ssuspension system. Rumble strips may beportable devices.

A warning sign may be placed in advanceof the strips.

E. Screens.

Screening is used to block the driver’sview of activities that can distract from thedriving task. Screening also contains thework zone and keeps dust and debris offthe pavement. Screens are primarily usefulon long-term temporary traffic controlprojects.

Screens may improve traffic flow wheretraffic volumes approach the roadwaycapacity because they discourage"gawking" and reduce headlight glare fromoncoming traffic.

Screens may be mounted on the top ofportable concrete barriers that separate two-way traffic. Screens should not be mountedwhere they could restrict driver visibilityand sight distance. Additional informationregarding screens can be obtained fromChapter 9 of the AASHTO RoadsideDesign Guide1, and Chapter 7 of theCaltrans Traffic Manual.

F. Opposing Traffic Lane Divider

Opposing traffic lane dividers aredelineation devices used as center lanedividers to separate opposing traffic on atwo-way operation. The upright, orange-colored panel shall be approximately 300mm wide by 450 mm high. The legend onthe panel shall be two opposing arrows,similar to those in the legend on the TWO-WAY TRAFFIC sign (W44, page 33).The divider should be made of lightweightreflectorized material. Dividers may bemounted on cones or tubular markers. SeeFigure 5-10.

1AASHTO, 44 North Capitol Street, N.W., Suite 225,Washington, D.C. 20001.


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5-06.1 Introduction

Each traffic control zone is different. Manyvariables, such as location of work, road type,speed, volume, geometrics, vertical and horizontalalignment, pedestrians, and intersections affectthe needs of each zone. The goal of traffic controlin work zones is safety with minimum disruptionto traffic; and, the key factor in making thetemporary traffic control zone safe and efficient isproper judgment.

Bicyclists also need protection and access tothe roadway. If a bikeway is closed because ofwork in progress, a signed alternate route shouldbe provided. Bicyclists should not be directedonto the same path used by pedestrians. If bicyclistsmust be directed onto the same path as pedestrians,bicyclists should be directed to dismountings. Formore details on controlling bicycle traffic, seeChapter 1000 of the Caltrans Highway DesignManual.

Short-term stationary work takes place bothwithin the roadway and outside the shoulder, toconstruct and maintain the hardware and equipmentused to provide power, light, water, gas, andtelephone service. Utility operations are generallyshort daytime operations, except under emergencyconditions. Often they are performed on low-volume, low-speed streets. Operations ofteninvolve intersections, as that is where many of thenetwork junctions occur. The crew size is usuallysmall, only a few vehicles are involved, and thenumber and types of traffic control devices placedin the temporary traffic control zone may beminimal. However, as discussed in Section 5-06.3.A.4, the reduced number of devices in thissituation should be offset by the use of high-visibility devices, such as special lighting units onwork vehicles. Figures TA5-6, TA5-10, TA5-15,TA5-18, TA5-21, TA5-22, TA5-23, TA5-26 and

TA5-33 are examples of typical applications forshort-term stationary operations. Other typicalsmay apply as well.

In this section, typical temporary traffic controlzone situations are organized according to durationand location of work and highway type. Section 5-07, which follows the same organization, presentslayouts of these typical temporary traffic controlzone situations. Table 5-4, in Section 5-07, indexesby figure number the typical temporary trafficcontrol zone applications described in this section.

5-06.2 Typical Applications

Typical applications include a variety of trafficcontrol methods, but do not include a layout forevery conceivable work situation. Typicalapplications should be altered, when necessary, tofit the conditions of a particular temporary trafficcontrol zone. Standards presented in Sections 5-01 through 5-05 should be given priority over theexamples given in the typical applications.

The typical applications illustrated in Section5-07 generally represent highway agency norms.Other devices may be added to supplement thedevices shown in the typical applications, and signspacings and taper lengths may be increased toprovide additional time or space for driver response.In some situations, however, such as an urbansetting, too many devices can spread signing overtoo long a distance to be meaningful. Whenconditions are not as difficult as those depicted inthe typical application, fewer devices may suffice.

Although portable barriers are frequentlyindicated in the typical applications of Section 5-07, they are not traffic control devices inthemselves. However, when placed in a positionidentical to a line of channelizing devices andmarked and/or equipped with appropriatechannelizing features to give guidance and warning

Types of Temporary Traffic Control Zone Activities 5-06


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both day and night, they serve as traffic controldevices and, therefore, must conform to allrequirements for such devices set forth throughoutthis manual.

5-06.3 Selecting the Typical Application

Selecting the most appropriate typicalapplication and modifications for a temporarytraffic control zone requires knowledge andunderstanding of that zone. Although there aremany ways of categorizing temporary trafficcontrol zone applications, the three factorsmentioned earlier (work duration, work location,and highway type) have been used to characterizethe typicals illustrated in Section 5-07.

A. Duration of Work

Work duration is a major factor indetermining the number and types ofdevices used in temporary traffic controlzones. The five categories of work durationand their time at a location are as follows:

• Long-term stationary Work thatoccupies a location more than 3 days.

• Intermediate-term stationary Work thatoccupies a location from overnight to 3days.

• Short-term stationary Daytime workthat occupies a location from 1 to 12hours.

• Short-duration-Work that occupies alocation up to 1 hour.

• Mobile-Work that moves intermittentlyor continuously.

1. Long-Term Stationary Work

At long-term stationary traffic controlzones, there is ample time to install andrealize benefits from the full range oftraffic control procedures and devicesthat are available for use. Generally,larger channelizing devices are used,as they have more retroreflectivematerial and offer better nighttimevisibility. The larger devices are alsoless likely to be displaced or tippedover; an important consideration duringthose periods when the work crew isnot present. Furthermore, as long-term operations extend into nighttime,retroreflective and/or illuminateddevices are required. Temporaryroadways and barriers can be provided,and inappropriate markings should beremoved and replaced with temporarymarkings.

2. Intermediate-Term Stationary Work

During intermediate-term stationarywork, it may not be feasible or practicalto use procedures or devices that wouldbe desirable for long-term stationarytraffic control zones, such as alteredpavement markings, barriers, andtemporary roadways. The increasedtime to place and remove these devicesin some cases could significantlylengthen the project, thus increasingexposure time. In other instances, theremight be insufficient payback time tomake more elaborate traffic controleconomically attractive.


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3. Short-Term Stationary Work

Most maintenance and utilityoperations are short-term stationarywork. The work crew is present tomaintain and monitor the temporarytraffic control zone. The use of flaggersis an option. Lighting and/orretroreflective devices should bechosen to accommodate varyingseasonal, climatic, and visibilitysituations.

4. Short Duration Work

During short-duration work, there isexposure involved for the crew insetting up and taking down the trafficcontrols. Also, since the work time isshort, the time during which motoristsare affected is significantly increasedas the traffic control is expanded.Considering these factors, it is generallyheld that simplified control proceduresmay be warranted for short-durationwork. Such shortcomings may be offsetby the use of other, more dominantdevices such as special lighting unitson work vehicles.

5. Mobile Work

Mobile operations are work activitiesthat move along the road eitherintermittently or continuously. Mobileoperations often involve frequent shortstops, each as much as 15 minuteslong, for activities such as litter cleanup,pothole patching, or utility operationsand are similar to stationary operations.Warning signs, flashing vehicle lights,flags, and/or channelizing devicesshould be used.

Mobile operations also include workactivities in which workers and equip-ment move along the road without stop-ping, usually at slow speeds. Theadvance warning area moves with thework zone. Traffic should be directedto pass. Parking may be prohibited,and work should be scheduled duringoff-peak hours. For some continu-ously moving operations such as streetsweeping where volumes are light andvisibility is good, a well-marked andwell-signed vehicle may suffice. Ifvolumes and/or speeds are higher, ashadow or backup vehicle equipped asa sign truck, preferably supplied with aflashing arrow display, should followthe work vehicle. Where feasible,warning signs should be placed alongthe roadway and moved periodicallyas the work progresses. In addition,vehicles may be equipped with suchdevices as flags, flashing vehicle lights,truck-mounted attenuators, and appro-priate signs. These devices may berequired individually or in various com-binations, including all of them, asdetermined necessary.

Safety should not be compromised byusing fewer devices simply becausethe operation will frequently changeits location. Portable devices shouldbe used. Flaggers may be used, butcaution must be exercised so they arenot unnecessarily exposed to traffic.The control devices should be movedperiodically to keep them near the workzone. If mobile operations are in effecton a high-speed travel lane of amultilane divided highway, flashingarrow displays should be used.


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B. Location of Work

The choice of traffic control needed for atemporary traffic control zone dependsupon where the work is located. As ageneral rule, the closer the work is totraffic, the more control devices are needed.

Work can take place in the followinglocations:

1. Outside of the shoulder edge. Devicesmay not be needed if work is confinedto an area 4.6 m or more from the edgeof the shoulder. Consideration shouldbe given to roadway characteristics,roadway geometrics, and vehicle speed.A general warning sign like ROADMACHINERY AHEAD should beused if workers and equipment mustoccasionally move closer to thehighway.

2. On or near the shoulder edge. Theshoulder should be signed as if workwere on the road itself, since it is partof the drivers' "recovery area."Advance warning signs are needed.Channelizing devices are used to closethe shoulder, direct traffic, and keepthe work space visible to the motorist.Portable barriers may be needed toprevent encroachment of errantvehicles into the work space and toprotect workers.

3. On the median of a divided highway.Work in the median may require trafficcontrol for both directions of traffic,through the use of advance warningsigns and channelization devices. Ifthe median is narrow, with a significant

chance for vehicle intrusion into long-term work sites and/or crossoveraccidents, portable barriers should beused.

4. On the traveled way. Work on thetraveled way demands optimumprotection for workers and maximumadvance warning for drivers. Advancewarning must provide a generalmessage that work is taking place,information about specific conditions,and actions the driver must take todrive through the temporary trafficcontrol zone.

C. Roadway Type

Roadway type is also a primary factor inthe use of temporary traffic control devices.Typical application diagrams of thefollowing categories of roadway type areincluded in Section 5-07:

1. Rural Two-lane Roadways2. Urban Arterial Roads3. Other Urban Streets4. Rural or Urban Multilane Divided and

Undivided Highways5. Intersections6. Freeways

Rural two-lane highways are characterizedby relatively low volumes and high speeds.Urban arterial roads often have lowerspeeds, but they may require significantcontrols because of higher traffic volumesand closer spacing of such design featuresas intersections. Other urban streets withlight traffic volumes will generally requirefewer, but more closely spaced devices.Major arterials and freeways need the


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highest type of traffic control, primarilybecause of high speeds and often highvolumes of traffic.

To improve traffic operations, typicaldesigns may be modified to a moreelaborate treatment, as indicated by thefollowing:

• Additional devices- Additional signs- Flashing arrow displays- More channelizing devices at closer

spacing- Temporary raised pavement markers- High-level warning devices- Portable changeable message signs- Portable traffic signals- Portable barriers- Crash Cushions- Screens- Rumble strips

• Upgrading of devices- A full complement of standard

pavement markings in areas of highconflicts

- Brighter and/or wider pavementmarkings

- Larger signs- Higher type channelizing devices- Barriers in place of channelizing

devices

• Improved geometrics at detours orcrossovers, giving particular attentionto the provisions set forth in Section 5-01.2

• Increased distances- Longer advance warning area- Longer tapers

• Lighting- Temporary roadway lighting-Steady-burn lights used with

channelizing devices- Flashing lights for isolated conditions- Illuminated signs- Floodlights

When conditions are not as difficult asthose depicted in the typical applications,fewer devices may suffice. However,uniformity of devices and their applicationis always extremely important.

5-06.4 Work Outside of the Shoulder

Traffic control depends primarily on devicessuch as advance warning signs, flashing vehiclelights, and flags. An advance warning sign shouldbe used when any of the following conditionsoccur:

• Work will be performed immediatelyadjacent to the shoulder at certain stages ofthe activity.

• Equipment may be moved along or acrossthe highway.

• Motorists may be distracted by the workactivity.

A typical sign for this situation may beSHOULDER WORK AHEAD. If the equipmenttravels on or crosses the roadway, it should beequipped with appropriate flags, flashing lights,and/or a SLOW MOVING VEHICLE symbol.

A typical layout for stationary work outside ofthe shoulder is shown in Figure TA5-1. Specialsigning for a blasting zone is shown in FigureTA5-2. A typical layout for short-duration, mobile


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and moving work outside of the shoulder and onthe shoulder is shown in Figure TA5-4.

5-06.5 Work on the Shoulder

This section describes typical applications thatcover shoulder work. It is divided into shoulderwork that does and does not interfere with traffic.

A. No Encroachment on Traveled Way

There is no direct interference with traffic.When the shoulder is occupied or closed,the drivers should be advised and theworkers should be protected. In someinstances, this may require the use ofportable barriers if work is directly adjacentto the travel lane. Usually, the singlewarning sign, SHOULDER WORKAHEAD, is adequate. When an improvedshoulder is closed on a high-speed highway,it should be treated as a closing of a portionof the road system because drivers expectto be able to use it in emergencies. Motoristsshould be given ample advance warningthat shoulders are closed to use as refugeareas throughout a specified length of theapproaching temporary traffic control zone.The signs should read SHOULDERCLOSED with distances indicated. Thework space on the shoulder should beclosed off by a taper of channelizing deviceswith a length of 1/3 L, using the formulasin Section 5-02.3. Flashing arrow signs,when used, shall be used only in the cautionmode.

B. Minor Encroachment on Traveled Way

When work is on the shoulder or takes uppart of a lane, traffic volumes, vehicle mix(buses, trucks, and cars), speed, and

capacity should be analyzed to determinewhether the affected lane should be closed.The lane encroachment should permit aremaining lane width of 3 m or the laneshould be closed. However, 2.7 m isacceptable for short-term use on low-volume, low-speed roadways for trafficthat does not include longer and widerheavy commercial vehicles. Figure TA-6illustrates a method for handling trafficwhere the stationary or short duration workspace encroaches slightly into the traveledway.

5-06.6 Work Within Traveled Way-Rural Two-Lane

A. Detours

Typical layouts for detours of two-lanehighways are shown in Figures TA5-7,TA5-8, and TA5-9. Figure TA5-7illustrates the controls around an area wherea section of roadway has been closed anda bypass constructed. Channelizing devicesand pavement markings are used to indicatethe transition to the temporary roadway.

Detour signing is usually handled by thetraffic engineer with authority over theroadway because it is considered a trafficrouting problem. Detour signs are used todirect traffic onto another roadway. Whenthe detour is long, signs should be installedto periodically remind and reassure driversthat they are still on a detour. This is doneby using the DETOUR sign (C5A).

When an entire roadway is closed, asillustrated in Figure TA5-8, a detour shouldbe provided and traffic should be warnedin advance of the closure. This illustrationis an example for a closing 16 km from the

(Rev. 1)


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intersection. If local traffic is allowed touse the roadway up to the closure, theROAD CLOSED TO THRU TRAFFICsign should be used. The portion of theroad open to local traffic should haveadequate signing, marking, and protection.

Detours should be signed so that trafficwill be able to get through the entire areaand back to the original roadway as shownin Figure TA5-9.

B. One-Way Traffic Control

When one lane is closed on two-lane, two-way roads, the remaining lane must beused by traffic traveling in both directions.Techniques for controlling traffic undersuch conditions are described in Section 5-02.5.

5-06.7 Work Within Traveled Way-Urban Streetsor Arterial

Urban temporary traffic control zones may bedivided into segments. Decisions must be reachedas to how to control vehicular traffic, how manylanes are required, or whether any turns should beprohibited at intersections. Pedestrian traffic mustbe considered. If work will be done on the sidewalk,it may be necessary to close the sidewalk andassign the pedestrians to another path. Next,decisions must be reached as to how to maintainaccess to business, industrial, and residential areas.Even if the road is closed to vehicles, pedestrianaccess and walkways must be provided.

Bicyclists’ protection and access are especiallyneeded on these types of roadways. If a bikewayis closed because of the work being done, a signedalternate route should be provided. Bicyclistsshould not be directed onto the path used bypedestrians. For more details on controlling bicycletraffic, see Chapter 1000 of the Caltrans HighwayDesign Manual.

Utility work takes place both within theroadway and outside the shoulder to construct andmaintain the hardware and equipment. Utilityoperations are generally daytime operations, exceptunder emergency conditions. Often they areperformed in low-volume and low-speed streets.Operations often involve intersections, since thatis where many of the network junctions occur. Thecrew size is usually small, only a few vehicles areinvolved, and the number and types of trafficcontrol devices placed in the temporary trafficcontrol zone may be minimal. However, asdiscussed in Section 5-06.3.A.4, in this situationthe reduced number of devices should be offset bythe use of high-visibility devices, such as speciallighting units on work vehicles. Figures TA5-6,TA5-10, TA5-15, TA5-18, TA5-21, TA5-22, TA5-23, TA5-26, and TA5-33 are examples of typicalapplications for utility operations. Other typicalsmay apply as well.

5-06.8 Work Within Traveled Way-Rural or Urban,Multilane Divided and Undivided, Non-Access Controlled

This section describes typical applications forwork on multilane (four or more) streets orhighways. It is divided into right lane closures, leftlane closures, multiple-lane closures, and closureson five-lane roadways.

Figure TA5-34 illustrates a lane closure inwhich portable concrete barriers are used. Asdescribed in Section 5-05.9, portable barriers arenot in themselves traffic control devices but, ifplaced along an adequate taper, transition, ortangent section, they may serve as traffic controldevices to provide guidance and warning to passingmotorists. In serving this traffic control function,portable barriers must be equipped with appropriatechannelizing devices, delineation, and/or othertraffic control devices in order to performacceptably during day and night operations. Whendetermined necessary by an engineering analysis,


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barriers should be used•to prevent incursions oferrant vehicles beyond their designated travel lanes.The four primary functions of barriers are asfollows:

• To keep traffic from entering work zones,such as excavations or material storagesites.

• To provide protection for workers andpedestrians.

• To separate two-way traffic.

• To protect roadwork such as false work forbridges and other exposed objects.

A. Right Lane Closed

Traffic control similar to that shown inFigure TA5-33 may be used for undividedor divided four-lane roads. If trafficvolumes are high, traffic may back up. Ifmorning and evening peak hourly trafficvolumes in the two directions are unevenand the greater volume is on the side wherethe work is being done, the inside lane foropposing traffic may be closed and madeavailable to the side with heavier traffic, asshown in Figure TA5-31. A volume checkin both directions should be made beforethis method is used.

If the heavier traffic changes to the oppositedirection, the traffic control can be changedto allow two lanes for opposing traffic bymoving the devices from the opposinglane back to the centerline. If these changesoccur frequently, cones or tubes should beused at close spacing to emphasize thecenterline.

B. Left Lane Closed

If the work activity can be containedentirely within the left (or inside) lane, itmay be appropriate to close only that lane.Channelizing devices should be placedalong the centerline and outside of thework activity to give advance warning tothe opposing traffic. An alternative is toclose the two center lanes, as shown inFigure TA5-30, to give motorists andworkers additional protection and toprovide easier access to the work space.Overall •needs, evaluated on the basis ofexisting traffic volumes and speeds in eachdirection, is the main factor for determiningalternatives.

C. Multiple Lanes Closed

When the work occupies multiple lanes forone direction of traffic, the number oflanes remaining open may be reduced toone for each direction as shown in FigureTA5-32. A capacity analysis is necessarybefore this method is initiated. Trafficshould be moved over one lane at a time asshown in Caltrans Standard Plan T10.When both center lanes are closed, trafficcontrols may be used as indicated in FigureTA5-30. When a roadway must be closedon a divided highway, a median crossovermay be used (see Section 5-06.10.B andC). When the directional roadway is closed,inapplicable WRONG WAY signs andmarkings, and other existing traffic controldevices at intersections within thetemporary two-lane, two-way operationssection, should be covered, removed, orobliterated.


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D. Five-Lane Roads

Traffic control for lane closures on five-lane urban or rural roads is similar to othermultilane undivided roads. Figures TA5-32 and TA5-34 should be adapted for useon five-lane roads. For short-duration andmobile operations, see Figure TA5-35.

5-06.9 Work Within Traveled Way-Intersections

For work at an intersection, advance warningsigns, devices, and markings are to be used asappropriate on all cross streets. The effect of thework upon signal operation should be considered,such as signal phasing for adequate capacity andfor maintaining or adjusting detectors in thepavement.

A shoulder closure is done as shown in FigureTA5-4. A minor encroachment is done as shownin Figure TA5-6.

When a lane is closed on the approach side ofan intersection, standard lane closure and tapertechniques apply, as shown in Figure TA5-21. Aturn lane may be used for through traffic.

When a lane must be closed on the far side ofan intersection, that lane should be closed on thenear side approach, or converted to an exclusiveturn lane, as shown in Figures TA5-22, TA5-23,TA5-24, and TA5-25. When traffic is confined toa single approach lane, turning prohibitions shouldbe considered.

If the work is within the intersection, severaloptions exist as follows:

• Keep the work space small so that trafficcan move around it, as shown in FigureTA5-26.

• Use flaggers to assign the right-of-way, asshown in Figure TA5-27.

• Do the work in stages so the work space iskept small.

• Reduce traffic volumes by road closing orupstream diversions.

5-06.10 Work Within Traveled Way-Freeways andExpressways

Traffic control issues occur under the specialconditions encountered where traffic must bemoved through or around temporary traffic controlzones on high-speed, high-volume roadways.Although the general principles outlined in theprevious sections of the manual are applicable toall types of highways, special consideration shouldbe given to modern, high-speed, access-controlledhighways to accommodate traffic in a •mannerthat also adequately addresses the needs of thework forces. The density of traffic on thesefacilities requires that detailed traffic controlprocedures be implemented•well in advance ofwork spaces and in a manner that creates minimumturbulence and delay in the traffic stream. Thesesituations may require more conspicuous devicesthan specified for normal rural or urban street use.However, the same important basic considerationsof uniformity and standardization of generalprinciples apply for all roadways.

The year-round, night-and-day intensity ofuse of expressways and freeways means that thereis no season during which work can be scheduledwhen traffic volumes and density are low. Theseactivities therefore must be performed underextremely heavy traffic conditions.

Traffic controls for short-duration and mobileoperations are shown in Figure TA5-35 for localroads and Caltrans Standard Plans T15, T16 andT17 for State highways.


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A. Potential Problem Areas

The performance of work under high-speed, high-density traffic on controlledaccess highways is complicated by manyof the design and operational featuresinherent to their use.

The presence of median dividers thatestablish separate roadways for directionaltraffic may also prohibit the closing of thatroadway or the diverting of traffic to otherlanes. A typical layout for shifting trafficlanes around a work space is shown inCaltrans Standard Plan T10.

Lack of access to and from adjacentroadways prohibits rerouting of trafficaway from the work space in many cases.

A major consideration in the establishmentof traffic control is the vehicular speeddifferential which exists and the limitedtime available for drivers to react to unusualconditions while still providing an activityarea that addresses the needs of the workforces. Traffic control for a typical laneclosure is shown in Figure TA5-33 andCaltrans Standard Plan T10.

Other conditions exist where work must belimited to night hours, thereby necessitatingincreased use of warning lights,illumination of work spaces, and advancewarning systems.

B. Two-Lane, Two-Way Traffic on OneRoadway of a Normally Divided Highway.

Two-lane, two-way operations (TLTWO)on one roadway of a normally divided

highway is a typical application thatrequires special consideration in theplanning, design, and construction phases.As operational problems can arise with theTLTWO, this typical application will bediscussed here.

Before including a TLTWO in the trafficcontrol plan for a project, carefulconsideration should be given to itsreasonableness. The following itemsshould be considered during the decision-making process:

• Is a suitable detour available?

• What are the characteristics of thetraffic?

• Can traffic be maintained on theshoulder?

• Can temporary lanes be constructed inthe median?

• Can the work be accomplished byclosing only one directional lane? Ifthis option is selected for consideration,what are the impacts to temporarytraffic control zone personnel?

• If a TLTWO is selected, will this resultin a shorter contract time?

• Will the TLTWO allow a contractor toperform the work more efficiently andthus result in a substantial decrease incontract cost?

• What is the "track record" of similarinstallations?


5-72

• Are there any width or heightrestrictions that would preclude theTLTWO or the use of a shoulder or themedian as a temporary lane?

• What are the condition of the travelway and shoulder pavements in theproposed TLTWO section? Due towidth restriction, traffic may drive onthe shoulders, which must bestructurally adequate.

• Consider detour using alternate routefor one direction of traffic.

The traffic control shall include provisionfor separating opposing traffic whenevertwo-way traffic must be maintained on oneroadway of a normally divided highway.The TLTWO shall be used only after carefulconsideration of other available methodsof traffic control.

When traffic control must be maintainedon one roadway of a normally dividedhighway, opposing traffic shall be separatedeither with portable barriers (concretesafety-shape or approved alternate), or withchannelizing devices throughout the lengthof the two-way operation. The use ofstriping, raised pavement markers, andcomplementary signing, either alone or incombination is not considered acceptablefor separation purposes.

Treatments for entrance and exit rampswithin the two-way roadway segment ofthis type of work are shown in CaltransStandard Plans T10 and T14.

C. Crossovers

The following are good guiding principlesfor the design of crossovers:

• Tapers for lane drops should not becontiguous with crossovers.

• Crossovers should be designed forspeeds not less than 16 km per hourbelow the posted speed, the off-peak85th percentile speed prior to workstarting, or the anticipated operatingspeed of the roadway, unless unusualsite conditions require that a lowerdesign speed be used.

• A full array of channelizing devices,delineators, and full-length, properlyplaced pavement markings areimportant in providing drivers with aclearly defined travel path.

• Portable concrete barriers and theexcessive use of traffic control devicescannot compensate for poor geometricdesign of crossovers.

• The design of the crossover shouldaccommodate all roadway trafficincluding bicycles, trucks, and buses.

• A clear area should be providedadjacent to the crossover.

D. Interchanges

Access to interchange ramps on limitedaccess highways should be maintained evenif the work space is in the lane adjacent tothe ramps. If access is not possible, ramps


5-73

may be closed by using signs and Type IIIbarricades (Type I or II if less than 2weeks.) Early coordination with officialshaving jurisdiction over the affected crossstreets is needed before ramp closings.

Egress to exit ramps should be clearlymarked and outlined with channelizingdevices. For long-term projects, oldpavement markings should be removedand new ones placed. As the work spacechanges, the access area may be changed.Traffic control work in the exit ramp maybe handled as shown in Caltrans StandardPlans T10 and T14. When a work spaceinterferes with an entrance ramp, a lanemay need to be closed on the freeway.Work in the entrance ramp may requireshifting ramp traffic. Traffic control forboth operations is shown in CaltransStandard Plan T14.

5-06.11 Control of Traffic Through Incident Areas

The primary function of traffic control at anincident area is to move traffic through or aroundthe incident. Also, proper traffic control throughincident areas is essential for fire and enforcementagency activities. An incident is an emergency,traffic collision, natural disaster, or special event.Examples include a stalled vehicle blocking alane, a traffic collision blocking the traveled way,a hazardous chemical spill closing a highway,floods and severe storm damage, a planned visit bya dignitary, or a major sporting event.

Emergencies and disasters may pose severeand unpredictable problems. The ability to installproper traffic control may be greatly reduced in anemergency, and any devices on hand may be usedfor the initial response as long as they do notthemselves create unnecessary additional

problems. If the situation is prolonged, the standardprocedures and devices set forth in this manualshall be used. Special events, on the other hand,can be properly planned for and coordinated. Thismanual provides standards for the proper procedurefor closing portions or entire roadways inconjunction with such activities.

Truck Route National Network and hazardouscargo signs are included in Chapter 4 of the CaltransTraffic Manual. During incidents, longer vehiclesmay need to follow a different route fromautomobiles because of bridge, weight, clearance,or geometric restrictions. Also, vehicles carryinghazardous materials may need to follow a differentroute from other vehicles.

The control of traffic through incident areas isan essential part of fire and enforcement operations.For these operations there must be adequatelegislative authority for the implementation andenforcement of needed traffic regulations, parkingcontrols, and speed zoning. Such statutes shouldprovide sufficient flexibility in the application oftraffic control to meet the needs of the changingconditions in incident areas.

Maintaining good public relations is necessary.The cooperation of the news media in publicizingthe existence of, and reasons for, incident areasand their traffic information can be of greatassistance in keeping the motoring public wellinformed.

Street or highway incident management signsfall into two major categories: regulatory signsand warning signs. Specifications for incidentsign design are presented in Section 5-05.2.

The channelizing devices discussed in Section5-05.6 should be used whenever possible. Flaresmay be used to initiate traffic control at all incidentsor for short-term traffic control such as clearingincident sites, but should be replaced by morepermanent devices as soon as practicable.


5-74

A short-term road closing caused by an incidentsuch as a traffic collision may block the traveledway. Traffic may be detoured around the incidentand back to the original roadway. The jurisdictionhaving control of the roadway will probably needto determine the detour route and install the signs.

Large trucks are a primary concern in such adetour.

An incident such as a hazardous chemical spillmay require closure of an entire highway. Localtraffic can adjust to the closure, but through trafficmust be guided around the incident and back to theoriginal route.

5-07.1 Typical Applications

Section 5-06 contains discussion of typicalactivities. Section 5-07 presents typical applicationdiagrams for a variety of situations commonlyencountered. While not every situation isaddressed, the procedures illustrated can generallybe adapted to a broad range of conditions. In manyinstances, it will be necessary to combine featuresfrom various typical application diagrams. Forexample, work at an intersection may present anear-side work zone for one street and a far-sidework zone for the other street. These treatmentsare found in two different diagrams, and a thirddiagram shows how to handle pedestrian crosswalkclosings.

Procedures for establishing temporary trafficcontrol zones vary with such conditions as roadconfiguration, location of the work, work activity,duration, traffic speed, traffic volume, andpedestrians. Examples presented in this sectionare guides showing how to apply principles andstandards. Judgment is needed in applying theseguidelines to actual situations and adjusting tofield conditions. In general, the proceduresillustrated represent the minimum needs for thesituation depicted. Other devices may be added tosupplement the devices and device spacing may beadjusted to provide additional reaction time orprotection. Where the situation being addressed isless than typical, actual conditions may requirefewer devices.

5-07.2 General Notes

General notes for various application categoriesare provided below. Numerous figures and tablesfound throughout this manual provide guidancefor the development of traffic control plans andprocedures. Several of these exhibits presented inprevious sections are repeated for convenienceafter the general notes. Note particularly Figure 5-11, which serves as the legend for symbols used inthe diagrams.

A. Work Performed on the Roadside (OutsideShoulder)

When work is being performed off theroadway (beyond shoulders yet within theright-of-way), little or no temporary trafficcontrol may be needed. If there is no effectupon traffic, no devices are needed, butthis is rarely the case. More commonly,there may be driver distraction, vehiclesmay be parked on the shoulder, vehiclesmay be accessing the work site via thehighway, or equipment may on occasionneed to travel on or cross the roadway toperform the work operation (e.g. mowing).Where these situations pertain, a singlewarning sign, such as C-22B, will generallysuffice.

Application of Devices 5-07


5-75

If vehicles are using the shoulder, aSHOULDER WORK AHEAD sign isappropriate. For mowing operations, thesign MOWING AHEAD may be used.Where the activity is spread out over adistance of more than 3 km, the sign shouldbe repeated approximately every 3 km. Asupplementary plate with the messageNEXT [X] MILES may be placed belowthe initial warning sign.

B. Work Performed on Shoulders

When a highway shoulder is occupied,warning is needed to advise the driver to beaware of the workers. As a minimum, thesingle warning sign SHOULDER WORKis adequate. When work is performed on apaved shoulder 2.4 m or more wide, atransition area is needed in whichchannelizing devices are placed on a taperof length that conforms to the requirementsof a shoulder taper. When paved shouldersof width of 2.4 m or more are closed onfreeways and expressways, additionaltreatment is generally needed to alert trafficto the possibility of a disabled vehicle thatcannot get off the traveled way. An initialgeneral warning sign is needed e.g. ROADWORK AHEAD, followed by aSHOULDER CLOSED sign. Where theend of the shoulder closure extends beyondthe distance that can be perceived bymotorists, a supplementary plate bearingthe message NEXT [X] MILES should beplaced below the SHOULDER CLOSEDsign.

When the shoulder is not occupied butwork has adversely affected its condition,the LOW SHOULDER or SOFTSHOULDER sign should be used, if

appropriate. Where the condition extendsover a distance in excess of 1500 m, thesign should be repeated at approximately1500 m intervals. In addition, asupplementary plate bearing the messageNEXT [X] MILES may be placed belowthe first such warning sign.

On multilane, divided highways, signsadvising of shoulder work, or the conditionof the shoulder, should be placed only onthe side of the affected shoulder.

C. Mobile and Short-Duration Operations

As compared to stationary operations,mobile and short-duration operations aredistinct activities that may involve differenttreatments. More mobile devices areneeded (e.g., signs mounted on trucks),and larger, more imposing, and more visibledevices can be used effectively andeconomically. For example, appropriatelycolored and marked vehicles with flashingor rotating lights, perhaps augmented withsigns or arrow displays, may be used inplace of signs and channelizing devices.The trade-off is economical because workduration is short. Mobility is essential, thecrew is always onsite, and some of thevehicles may be required for the workactivity or crew transportation. Safety isnot compromised, as numerous smalldevices are merely replaced by fewer, moredominant and effective devices.

1. Short Duration

Short-duration activities are generallyconsidered to be those in which it takeslonger to set up and remove the trafficcontrol zone than to perform the work.


5-76

Typically, such operations can beaccomplished in 60 minutes or less.

The crew must exercise caution insetting up and taking down a trafficcontrol zone. Also, as the work time isshort, the time during which motoristsare affected is significantly increasedwhen additional devices are installedand removed. Considering thesefactors, it is generally held thatsimplified control procedures arewarranted for short-duration activities.Such shortcomings may be offset bythe use of other, more dominantdevices, such as special lighting unitson work vehicles.

2. Mobile Operations

Mobile operations include activitiesthat stop intermittently and then moveon (e.g., pothole patching and litterpickup) and those that movecontinuously (e.g., pavement striping).

With operations that move slowly (lessthan 5 km/h), it may be feasible to usestationary signing that is periodicallyretrieved and repositioned in theadvance warning area. At higherspeeds, trucks are typically used ascomponents of the traffic control zones.Appropriately colored and markedvehicles with signs, flashing or rotatinglights, and special lighting panels moveas part of a train behind the workvehicles.

Mobile operations that move at speedsgreater than 30 km/h, such assnowplowing operations, shall have

appropriate devices on the equipment,(i.e., rotating lights, signs, or speciallighting), or shall use a protectionvehicle with appropriate warningdevices.

D. Lane Closures on Two-Lane Roads

When one lane of a two-lane road is closed,the remaining lane must accommodate bothdirections of travel. The typical procedurefor short-term work is to utilize flaggers toalternate traffic flow, as shown in FigureTA5-10. For long-term operations, atemporary traffic signal, as shown in FigureTA5-12, is an alternative. For low trafficvolumes on a minor road, where trafficmay be self-regulating, the procedureillustrated in Figure TA5-11 may be used.

E. Lane Closures on Multilane Roads

When a lane is closed on a multilane road,a transition area containing a merging taperis needed. Typically, the advance warningarea contains three warning signs, such asROAD WORK AHEAD, RIGHT or LEFTLANE CLOSED AHEAD, and the LaneReduction Transition sign.

When an interior lane is closed for use as awork space, consideration should be givento closing an adjacent lane also. Thisprocedure provides additional space forvehicles and materials and facilitates themovement of equipment within the workspace. On multilane undivided roads andstreets where the left lane is closed, suchadditional space can be obtained by alsoclosing the left lane in the opposingdirection.


5-77

F. Work Performed in the Vicinity ofIntersections

The typical application diagrams containedherein depict typical urban intersectionson arterial streets. Where the posted speed,the off-peak 85th percentile speed prior towork starting, or the anticipated speed oftraffic equals or exceeds 70 km/h additionalwarning signs may be needed in the advancewarning area.

The typical application diagrams forintersections are classified according tothe location of the work space with respectto the intersection area (as defined by theextension of curb or edge lines.) Thus,there are three classifications; near-side,far-side and in-the-intersection.

Traffic control zones in the vicinity ofintersections may block movements andinterfere with normal traffic flows. Suchconflicts frequently occur at complexsignalized intersections having suchfeatures as traffic signal heads overparticular lanes, lanes allocated to specificmovements, multiple signal phases, andsignal detectors for actuated control. Wheresuch potential problems exist, the trafficengineering staff having jurisdiction shouldbe contacted.

It should be recognized that some workspaces may extend into more than oneportion of the intersection. For example,work in one quadrant may create a near-side work space on one street and a far-sidework space on the cross street. In suchinstances, the traffic control zone shouldincorporate features shown in two or moreof the intersection and pedestrian typicalapplication diagrams shown herein.

1. Work Space on the Near Side ofIntersections

Near-side work spaces, as depicted inFigure TA5-21, are simply handled asa mid-block lane closure. Where spaceis restricted, as with short blockspacings, two warning signs may beused in the advance warning area, anda third "action-type" warning orregulatory sign (e.g., KEEP LEFT) isplaced within the transition area. Oneproblem that may occur with a near-side lane closure is a reduction incapacity, which during certain hoursof operation could result in congestionand backups.

2. Work Space on the Far Side ofIntersections

Far-side work spaces require additionaltreatment because motorists typicallymay enter the activity area by straight-through and left or right-turningmovements. Merging movementswithin the intersection should beavoided. Therefore, the applicableprinciple is to close any lanes on thenear-side intersection approach that donot carry through the intersection aslanes shown in Figures TA5-22, TA5-23, TA5-24, and TA5-25. If, however,there is a significant number of vehiclesturning from this lane, then it may beadvantageous to convert the lane to anexclusive turn lane.

3. Work Space Within the Intersection

Figures TA5-26 and TA5-27 provideguidance as to applicable proceduresfor work performed within the


5-78

intersection. When directing trafficwithin the intersection, considerationshould be given to using a uniformedpolice officer.

G. Incident Management Situations

The immediate response to an emergencysituation must by necessity make use ofavailable devices and equipment. Giventhe opportunity, however, longer termemergencies should be treated in a mannersimilar to other temporary traffic controlwork sites.

H. Features That May Be Added to theDiagrams

The measures described below are usefulin increasing conspicuity and visibility oftraffic control devices.

1. Flags on Signs

Flags may be placed above signs toenhance their target value and increasemotorists’ awareness. Flags are usefulfor daytime operations only.

2. Flashing Lights on Signs

Portable warning lights may be placedabove signs to enhance their targetvalue and increase motorists'awareness. Type A low-intensitywarning lights are effective at night.Type B high-intensity warning lightsare effective for both day and night.

3. Sign Illumination

The retroreflective material used onsign faces returns light to a light source.In some instances, vehicular headlightbeams may not illuminate a sign, suchas those placed on sharp curves or oncrossroads. Likewise, some road users,such as pedestrians and cyclists, mayhave inadequate head lamps or no headlamps at all. When these situations areencountered, adequate nighttime signvisibility may be obtained using internalor external sign illumination.

4. Lights on Channelizing Devices

For intermediate and long-termoperations, consideration should begiven to placing portable warning lightson channelizing devices. Lights areespecially effective in the followingapplications: where new travel patternsare established at tapers, shifts, andrunarounds; at road closings; on devicesplaced on horizontal and verticalcurves; when adverse weatherconditions are anticipated; whereheadlights may not adequatelyilluminate retroreflective material onchannelizing devices.

5-07.3 Typical Application Diagrams

Table 5-5 is an index of typical applicationdiagrams. The remainder of the chapter containsthe typical application diagrams on the right pagewith notes on the facing page to the left. Thelegend for the symbols used in the diagrams isprovided as Figure 5-11.

(Rev. 1)


5-79

Table 5-4 provides numerical values for thetaper length 'L', the buffer space, and the advancewarning sign spacing 'A' used in the typicalapplication diagrams.

The taper length is discussed in Section 5-02.3. See Table 5-2 for the taper length formulas.

The buffer space is discussed in Section 5-02.2B3. Table 5-1 provides the length of the

buffer space for various speeds. Table 5-1 isrepeated on Table 5-4

The advance warning sign spacing is discussedin Section 5-05.2. Table 5-3 provides sign spacingdimensions for various area and road types. Basedon engineering judgment, the sign spacing may beadjusted for site specific conditions. The applicablepart of Table 5-3 is repeated on Table 5-4.

(Rev. 1)


5-80

Table 5-4Taper Length, Buffer Space and Advance Warning Sign Spacing

Used in Typical Application Diagrams

*Posted speed, off-peak 85th percentile speed prior to work starting, or the anticipated operation speed.**For other offset widths, apply the formula in Table 5-2.

For State highways, see Traffic Control Systems in the Caltrans Standard Plans.

Length ofLongitudinal Buffer Space

Length ofLongitudinal Buffer Space


30405060708090

100110


in Meters

101728436284

106136170

Speed inMiles

Per Hour*

2025303540455055606570


in Feet

355585

120170220280335415485585

*Posted speed, off-peak 85th percentile speed prior to work starting, or the anticipated operation speed.

AdvanceWarning Sign Spacing 'A'

*These are suggested distances for Advance Warning Signs, adequate sight distances and proximity to other roadway features may dictate the need for adjustments when placed.

AdvanceWarning Sign Spacing 'A'

Road TypeDistance

Between Signsin Feet*

Urban - 25 mph or less 200

Urban - 30 mph or more

Rural

Expwy/Fwy

350

500

1000

Road TypeDistance

Between Signsin Meters*

Urban - 40 km/h or less 60

Urban - 50 km/h or more

Rural

Expwy/Fwy

100

150

300

English MeasurementsLength of Taper 'L' in Feet

Speed inMiles

Per Hour*

2025303540455055606570

Width of Offset**

11 Feet 12 Feet

73115165225293495550605660715770

80125180245320540600660720780840

Metric MeasurementsLength of Taper 'L' in Meters


30405060708090

100110

Width of Offset**

3.3 Meters 3.6 Meters

20355579

154176198220242

22386086

168192216240264

(Rev. 1)


5-81

Table 5-5aIndex to Typical Application Diagrams

Roadside (Outside of Shoulder) - All RoadwaysWork Beyond the ShoulderBlasting Zone

Shoulder - All RoadwaysWork on ShouldersMobile Operation on ShoulderShoulder Closed on Limited Access HighwayShoulder Work with Minor Encroachment

Within Traveled Way - Rural Two-LaneRoad Closed with On-Site DetourRoad Closed with Off-Site DetourRoads Opened and Closed with DetourLane Closure on Two-Lane Road Using FlaggersLane Closure on Low-Volume, Two-Lane RoadLane Closure on Two-Lane Road Using Trafic SignalsTemporary Road ClosureHaul Road CrossingWork in Center of Low-Volume RoadSurveying Along Centerline of Low-Volume RoadMobile Operations on Two-Lane Road

Urban StreetsLane Closure on Minor StreetDetour for One Travel DirectionDetour for Closed Street

Intersections and WalkwaysLane Closure Near Side of IntersectionRight Lane Closure Far Side of IntersectionLeft Lane Closure Far Side of IntersectionHalf Road Closure Far Side of IntersectionMultiple Lane Closures at Intersection

Duration of Work

Stationary* /Short

Duration***

Mobile**

TA-1TA-2

TA-3

TA-5TA-6

TA-7TA-8TA-9TA-10TA-11TA-12TA-13TA-14TA-15TA-16

TA-18TA-19TA-20

TA-21TA-22TA-23TA-24TA-25

TA-4

TA-17

Type of Application

(Rev. 1)


5-82

Table 5-5bIndex to Typical Application Diagrams

Closure in Center of IntersectionClosure at Side of IntersectionSidewalk Closures and Bypass WalkwayCrosswalk Closures and Pedestrian Detours

Multilane UndividedInterior Lane Closure on Multilane StreetLane Closure on Streets withUneven Directional VolumesHalf Road Closure on Multilane High Speed Highways

Multilane DividedLane Closure on Divided HighwayLane Closure with BarrierMobile Operation on Multilane Road

FreewaysSee Standard Plans

TA-26TA-27TA-28TA-29

TA-30

TA-31TA-32

TA-33TA-34

TA-35

Duration of Work

Mobile**Stationary* /Short

Duration***

Type of Application

* Long-term Stationary: More than 3 days; Intermediate-term Stationary: Overnight up to 3 days;Short-term Stationary: Anytime, more than 60 minutes.

** Mobile: Intermittent and continuous moving.*** Short-duration: Up to 60 minutes

(Rev. 1)


5-83

Figure 5-11Legend of Symbols Used in Typical Application Diagrams

Surveyor

Traffic or Pedestrian Signal

Truck Mounted Crash Cushion

Type III Barricade

Changeable Message Sign (CMS)

CMS Support or Trailer

Warning Light

Work Space

Portable Barrierwith Warning Lights

Work Vehicle

Flashing Arrow Sign (FAS)

FAS Support or Trailer

Channelizing Device

Direction of Traffic

Direction of Temporary Traffic or Detour

Flagger

High Level Warning Device (Flag Tree)

Luminaire

Pavement Markings that shoud be removed for a Long Term Project

Sign (Shown Facing Left)

Portable Barrier

(Rev. 1)


Work Beyond the Shoulder

1. The signs illustrated in this figure are not required if the work space is behind a barrier, more than 0.6m behind the curb, or 4.6 m or more from the edge of any roadway.

2. The C-22B WORKER symbol sign may be replaced with other appropriate signs, such as theSHOULDER WORK AHEAD sign. The SHOULDER WORK AHEAD sign may be used for workadjacent to the shoulder.

3. If the work space is in the median of a divided highway, an advance warning sign should also be placedon the left side of the directional roadway.

4. For short-term, short-duration, or mobile operation, all signs and channelizing devices may be eliminatedif a vehicle with an activated flashing or revolving yellow light is used.


A

Typical Application 5-1Work Beyond the Shoulder

Note:See Table 5-4

for 'A'.

(Rev. 1)


Blasting Zone

1. Whenever blasting caps are used within 300 m of a roadway, the signing shown is required. On a dividedhighway, the signs should be mounted on both sides of the directional roadways.

2. The signs shall be covered or removed when there are no explosives in the area or when the area isotherwise secure.

3. Whenever a side road intersects the roadway between the BLASTING ZONE AHEAD (300 m) sign andthe END BLASTING ZONE sign, or a side road is within 300 m of any blasting cap, similar signing,as on the mainline, shall be erected on the side road.

4. Prior to blasting, the blaster in charge shall determine whether highway traffic in the blasting zone willbe endangered by the blasting operation. If there is danger, highway traffic shall not be permitted to passthrough the blasting zone during blasting operations.


Typical Application 5-2Blasting Zone

BlastingArea

300 m Min.

ZONEBLASTING

END

Blasting Zone

300 m Min.

90 m - 150 m

BLASTINGZONE

AHEAD


ANDCELLULAR

TELEPHONES

90 m - 150 m

ZONE

BLAS

TING

END

ZONEBLASTING

END

BLASTINGZONE

AHEAD

90 m -150 m 300 m 300 m

or lessTW

O-WAY RADIOS

TURN OFF

ANDCELLULAR

TELEPHONES

BLASTINGZONE

AHEAD


ANDCELLULAR

TELEPHONES

(Rev. 1)


Work on Shoulders

1. The ROAD WORK AHEAD sign on an intersecting roadway is not required if drivers emerging fromthat roadway will encounter another advance warning sign before they reach this activity area.

2. A SHOULDER WORK AHEAD sign should be placed on the left side of a divided or one-way roadwayonly if the left shoulder is affected.

3. For short-duration operations 60 minutes or less, all signs and channelizing devices may be eliminatedif a vehicle with an activated flashing or revolving yellow light is used.

4. WORKER signs may be used instead of SHOULDER WORK AHEAD signs.


Typical Application 5-3Work on Shoulders

A

A

1/3 L

A

1/3 L

A

1/3 L

ROAD WORKEND

(Optional)

(Optional)

(Optional)

(Optional)

SHOULDERWORKAHEAD

SHOULDERWORKAHEAD

SHOULDERWORKAHEAD

SHOULDERWORKAHEAD

SHOULDERWORKAHEAD

NEXT X MILESROAD WORK

ROAD WORKEND

NEXT X MILESROAD WORK

Note:See Table 5-4for 'A' and 'L'.

(Rev. 1)


Mobile Operation on Shoulder

1. In situations where multiple work locations in a limited distance make it practicable to place stationarysigns, the maximum spacing for the advance warning sign is 8 km in advance of the work.

2. The length of activity area sign may be used as the stationary advance warning sign if the work locationsoccur over a distance of more than 3.2 km.

3. Warning signs are not required if the work vehicle displays a flashing or revolving yellow light, if thedistance between work locations is 1.6 km or more, and if the work vehicle travels at traffic speedsbetween locations.


Typical Application 5-4Mobile Operation on Shoulder

See Note 1

(Optional)

(Optional)

Truck Mounted Crash Cushion(Optional)

X MILESNEXT

or

SHOULDERCLOSED

SHOULDERWORKAHEAD

(Rev. 1)


Shoulder Closed on Limited Access Highway

1. SHOULDER CLOSED signs should be used on limited-access highways where there is no opportunityfor disabled vehicles to pull off the traveled way.

2. If motorists cannot see a pull-off area beyond the closed shoulder, information regarding the length ofthe shoulder closure should be provided in meters or kilometers, as appropriate.

3. The barrier in this diagram shows one method that may be used to close a shoulder of a long-term project.The use of a barrier should be based on the need determined by an engineering analysis. The warninglights shown on the barrier are optional.

4. Barriers should be flared beyond the clear zone to prevent vehicles from impacting their leading ends.An alternative procedure is to place a crash cushion to protect traffic from the end of the barrier.


Typical Application 5-5Shoulder Closed on Limited Access Highway

Barrier Lights(Optional)

1/3 L

150 m

A

A

SHOULDERWORKAHEAD

SHOULDERCLOSEDXXX FT

SHOULDERCLOSED

X MILESNEXT


(Rev. 1)


Shoulder Work with Minor Encroachment

1. The treatment shown may be used on a minor road having low speeds. For higher speed trafficconditions, a lane closure should be considered.

2. The procedure shown should be adequate to carry bidirectional traffic at reduced speed through theactivity area, provided the lanes are at least 3 m wide.

3. Where the opposite shoulder is suitable for carrying traffic and of adequate width, traffic lanes may beshifted by use of closely spaced channelizing devices, provided 3 m wide lanes are maintained.

4. Additional advance warning may be appropriate, such as a ROAD (LANE) NARROWS sign.

5. Approved portable barriers may be used along the work space.

6. The protection vehicle is optional if a taper and channelizing devices are used. For short-duration work,the taper and channelizing devices are optional if the protection vehicle with an activated flashing yellowlight is used.


Typical Application 5-6Shoulder Work with Minor Encroachment

A

Truck MountedCrash Cushion

(Optional)

1/3 L

3 mMin.

A

(Optional)

(Optional)

(Optional)

ROAD WORKEND

ROAD WORKEND SHOULDER

WORKAHEAD

SHOULDERWORKAHEAD


(Rev. 1)


Road Closed with On-Site Detour

1. Signs shown are for one direction of travel only.

2. Flashing warning lights and/or flags may be used to call attention to the initial warning signs.

3. Where the temporary pavement and old pavement are different colors, the temporary pavement shouldstart on the tangent of the existing pavement and end on the tangent of the existing pavement.

4. Pavement markings that are no longer applicable shall be removed or obliterated as soon as practicable.

5. Delineators or channelizing devices may be needed along the bypass roadway.

6. If the detour is short and has sharp curves (50 km/h or less), REVERSE TURN signs should be used withappropriate speed advisory plate. In addition, LARGE ARROW signs may be desirable on sharp curves.

7. For the second reverse curve, when there is insufficient advance warning distance to place a REVERSECURVE or TURN sign, LARGE ARROW signs should be used on both curves.

8. If the tangent distance along the temporary bypass roadway is short and the curvature is sharp, twoLARGE ARROW signs may be required for the second reverse curve.

9. W 81 signs may be used to delineate the curve.


Typical Application 5-7Road Closed with On-Site Detour

Interim PavementStarts Here

ROADCLOSED

XXMPH

A

A

A

A

InterimDouble-Yellow

Center Line

ROAD WORKEND

XXMPH

Interim PavementEnds Here

150 m

(Optional)

(Optional)

InterimWhite Edge Line

(Optional)

DETOURAHEAD

ROADWORK

XXXX FT

ROADWORKXXX FT

(Optional)

Note:See Table 5-4

for 'A'.

(Rev. 1)


Road Closed with Off-Site Detour

1. Regulatory traffic control devices are to be modified as needed for the duration of the detour.

2. If the road is opened for some distance beyond the intersection and/or there are significant origin/destination points beyond the intersection, place the ROAD CLOSED and DETOUR signs on Type IIIbarricades located at the edge of the traveled way.

3. If the road is closed a short distance beyond the intersection and there are few origin/destination pointsbeyond (e.g., a few residences), the ROAD CLOSED and DETOUR sign may be placed on a Type IIIbarricade placed in the center of the roadway.

4. A route marker directional assembly may be placed on the far left corner of the intersection to augmentor replace the one shown on the near right corner.

5. Flashing warning lights and/or flags may be used to call attention to the advanced warning signs.


Typical Application 5-8Road Closed with Off-Site Detour

150 m

ROADCLOSED

ROADCLOSED500 FT

ROADCLOSED1000 FT

DETOUR1500 FT

150 m

150 m

ROAD CLOSED10 MILES AHEADLOCAL TRAFFIC ONLY

DETOUR

DETOUR

4

DETOUR

4

WES

T

DETO

UR 4

300 m

± 60 m

Note:Signing shown forone direction only.


Roads Opened and Closed with Detour

1. Similar signs and devices shall be erected for the opposite direction.

2. STOP signs displayed to side roads should be erected along the temporary route.


4. Flashing warning lights may be used on Type III barricades.


Typical Application 5-9Roads Opened and Closed with Detour

17

17

17 EAST

DETO

UR

174TO

DETO

UR

174TO

4NORTH

17

4DETOUR

4

DETOUR

4

ROAD CLOSEDXX MILES AHEADLOCAL TRAFFIC ONLY

ROAD CLOSED10 MILES AHEADLOCAL TRAFFIC ONLY

DETOUR

DETOUR

4DETOUR

4

DETO

UR 4

4DETOUR

4DE

TOUR

1744NORTH WEST

DETOUR

SOUTH

4DE

TOUR

17WEST

4SOUTH

1744NORTH WEST

DETOUR

SOUTH

DETOURDETOUR

ROAD CLOSEDXX MILES AHEAD

DETOUR

4DETOUR

17OPEN

4 17

DETOURAHEAD

DETO

UR 4

DETOUR

4

DETOUR

44

17

DETO

UR 4

4DETOUR OPEN

17

(Rev. 1)


Lane Closure on Two-Lane Road Using Flaggers

1. Floodlights should be provided to mark flagger stations at night as needed.

2. For low-volume applications, a single flagger may be adequate. Where one flagger can be used, suchas for short work zones on straight roadways, the flagger must be visible to approaching traffic from bothdirections.

3. Channelizing devices are to be extended to a point where they are visible to approaching traffic.

4. The ROAD WORK AHEAD sign may be omitted for short-duration operations or when the end of thework zone is obvious.


6. For State highways, see Caltrans Standard Plan T13.


Typical Application 5-10Lane Closure on Two-Lane Road Using Flaggers

15 - 30 m

A

A

A

30 m

A

A

A

(Optional)

(Optional)

(Optional)

ROADWORK

XXXX FT

ONE LANEROAD

XXXX FT

ROAD WORKEND

PREPARETO

STOP

(Optional)

PREPARETO

STOP

(Optional)ROAD WORK

END

(Optional)

ROADWORK

XXXX FT

ONE LANEROAD

XXXX FTFEETXXX

FEETXXX

Note:See Table 5-4

for 'A'.

(Rev. 1)


Lane Closure on Low-Volume, Two-Lane Road

1. This temporary application may be used as an alternate traffic control plan to the lane closure withflaggers (TA 5-10), when the following conditions exist.

a. Traffic volume is such that sufficient gaps exist for traffic that must yield.

b. Drivers from both directions must be able to see approaching traffic through and beyond the worksite.

2. The YIELD sign and YIELD AHEAD sign may be covered and flaggers used, as needed, during daylightworking hours to control the flow of traffic through the work space. When flaggers are used, theFLAGGER sign shall be used in place of the YIELD AHEAD sign.

3. The Type A flashing warning lights may be placed on the ROAD WORK AHEAD and the ONE LANEROAD AHEAD signs, whenever a night lane closure is necessary.


Typical Application 5-11Lane Closure on Low-Volume, Two-Lane Road

ROAD WORKEND

30 m Max.

Buffer Space (Optional)

Buffer Space (Optional)

A

A

A

ROAD WORKEND

XXMPH

ROADWORKAHEAD

ONE LANEROAD

AHEAD

(Optional)

(Optional)

(Optional)

(Optional)

(Optional)

A

A

Note:See Table 5-4

for 'A' and Buffer Space.

XXMPH

30 m Max.YEILD

TOONCOMING

TRAFFIC

ROADWORKAHEAD

ONE LANEROAD

AHEAD

(Optional)

(Optional)

(Optional)

(Rev. 1)


Lane Closure on Two-Lane Road Using Traffic Signals

1. Temporary traffic signals are preferable to flaggers for long-term projects and other activities that wouldrequire flagging at night.

2. The maximum length of activity area for one-way traffic signal control is determined by the capacityrequired to handle the peak hour demand. Practical maximum length is 120 m. Signal timing shall beestablished by qualified personnel.

3. Signals shall be installed and operated in accordance with the requirements of Chapter 9 of the CaltransTraffic Manual. Temporary traffic control signals shall meet the physical display and operationalrequirements of conventional traffic signals.

4. Adequate area illumination to clearly identify both ends of the work space at night for long-termoperations should be provided.

5. Stop lines 300 to 600 mm wide shall be installed. Add “no-passing” lines when necessary. Removablepavement markings may be used. Conflicting pavement markings and raised pavement marker reflectorsbetween the activity area and the stop line shall be removed. After completion of the work, the stop linesand other temporary inapplicable pavement markings shall be removed.

6. The Type A flashing warning lights shown on the ROAD WORK AHEAD and the ONE LANE ROADAHEAD signs may be used whenever a night lane closure is necessary. Type B lights may be used toalso increase the daytime target value of the signs.

7. The horizontal or vertical alignment of the roadway may require adjustments in the location of theadvance warning signs (the distances shown for advance warning sign spacings are minimums). Thevertical alignment of the roadway may require adjustments in the height of the signal heads.

8. When the signal is changed to a flash condition either manually or automatically, red shall be flashed toboth approaches.

9. CMS may be used to supplement this sign package.

(Rev. 2)


(Rev. 2)

Typical Application 5-12Lane Closure on Two-Lane Road Using Traffic Signals

XXMPH

12 m - 45 m

12 m - 45 m

30 m

L

A

A

A

ROADWORKAHEAD

ROAD WORKEND

(Optional)

(Optional)

(Optional)

(Optional Lighting)

STOPHERE ON

RED

15 m

Interim PavementMarkings

150 mto

180 m

150 mto

180 m


XXMPH

ROADWORKAHEAD

(Optional)

(Optional)

(Optional)

STOPHERE ON

RED

A

A

A

(Optional)

(Optional)

ROAD WORKEND

ONE LANEROAD

AHEAD

ONE LANEROAD

AHEAD



Temporary Road Closure

1. Conditions represented are for work that requires closures during daytime hours only.

2. This application is intended for a planned temporary closure not to exceed 15 to 20 minutes.

3. The flaggers shall stop the first vehicle from the position shown, then move to the centerline to stopapproaching traffic.

4. For high-volume roads, a police patrol car and/or a changeable message sign may be added.

5. A portable changeable message sign may be used in addition to the initial warning sign, per Section 5-05.3B, Application.

(Rev. 2)


(Rev. 2)

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Haul Road Crossing

This diagram shows two different methods of traffic control; flagging and a temporary traffic signal. Themethod selected is to be used in both directions.

Unsignalized Crossing

1. This typical application diagram as shown is intended for short-term use during daylight hours.

2. When the haul road is not in use, Type III barricades shall be in place. The FLAGGER signs shallbe covered.

3. The flagger shall stop the first vehicle from the position shown, then move to the centerline to stopapproaching traffic.

Signalized Crossing

1. Dashed yellow centerline, if existing, between the stop lines shall be removed before the beginningof roadwork and replaced before opening to normal traffic.

2. When the haul road is not in use, Type III barricades shall be in place. The Signal Ahead symbol signand STOP HERE ON RED sign, and traffic signals, shall be covered or hidden from view.

3. Traffic signals shall be two-direction type with push-button activation. The temporary traffic controlsignals shall meet the physical display and operational requirements of conventional traffic signalsas described in Chapter 9 of the Caltrans Traffic Manual.

Floodlighting

1. When hauling during hours of darkness and existing lighting is inadequate, floodlights should beused to illuminate haul road crossings.


Typical Application 5-14Haul Road Crossing

ROAD WORKEND

9 m Max.

A

A

ROADWORKAHEAD

(Optional-use only with

DO NOT PASSsign)


ROADWORKAHEAD

A

A

A

HaulRoad

PASSNOTDO

PASSINGNO

ZONE

PASSNOTDO

STOPHERE ON

RED

PREPARETO

STOP

A

(SeeNote 2)

(SeeNote 2)

FlaggingMethod

A

12 m - 45 m

PASSINGNO

ZONE

SignalMethod

(Optional-use only with

DO NOT PASSsign)

(Optional)(Optional)

Note:See Table 5-4 for 'A'.


Note:See Table 5-4 for 'A'.

(Rev. 1)


Work in Center of Low-Volume Road

1. The lanes on either side of the center work space should have a minimum width of 3 m, as measured fromthe near edge of the channelizing devices to the edge of pavement, or the outside edge of paved shoulder.

2. A minimum of six channelizing devices should be used for each taper. However, a work vehicledisplaying a flashing or revolving yellow light may be used instead of the tapers.


4. If the closure continues overnight, warning lights may be used to mark channelizing devices.


Typical Application 5-15Work in Center of Low-Volume Road

3 m minimum to edge of pavement or outside edge of paved shoulder. See Note 1. A

ROADWORKAHEAD

1/2 L

A

ROADWORKAHEAD

1/2 L

ROAD WORKEND

ROAD WORKEND

(Optional)

(Optional)


(Rev. 1)


Surveying Along Centerline of Low-Volume Road

1. The same treatment is required in both directions.

2. Cones should be placed 150 to 300 mm on either side of the center line.

3. Maximum spacing between cones is 30 m.

4. For a survey along the edge of the road or along the shoulder, the advance signing remains the same. Forthis situation, place cones along the edge line. A flagger is not required for work along the shoulder.

5. Cones may be omitted for a cross-section survey.

6. For surveying on the centerline of a high-volume road, close one lane, using the procedure illustrated inFigure TA-10.

7. ROAD WORK AHEAD signs may be used in place of SURVEY CREW signs.

8. A flagger should be used to protect people who must work with their backs to traffic. A high-levelwarning device may be used to protect a surveying device, such as a target on a tripod. Workers in theroadway should wear high-visibility clothing.

9. Flags may be used to call attention to the advance warning signs.


Typical Application 5-16Surveying Along Centerline of Low-Volume Road

60 m Minimum

A

A

60 m Minimum

A

A

SURVEYCREW

SURVEYCREW

Note:See Table 5-4

for 'A'.

(Rev. 1)


Mobile Operations on Two-Lane Road

1. Where practicable, and when needed, the work and protection vehicles should pull over periodically toallow traffic to pass. If this can not be done frequently, as an alternative, a DO NOT PASS sign may beplaced on the rear of the vehicle blocking the lane.

2. The distance between the work and protection vehicles may vary according to terrain, paint drying time,and other factors. Protection vehicles are used to warn traffic of the operation ahead. Whenever adequatestopping sight distance exists to the rear, the protection vehicle should maintain the minimum distanceand proceed at the same speed as the work vehicle. The protection vehicle should slow down in advanceof vertical or horizontal curves that restrict sight distance.

3. Additional protection vehicles to warn and reduce the speed of oncoming or opposing traffic may beused. Police patrol cars may be used for this purpose.

4. A truck-mounted crash cushion (TMCC) should be used on the protection vehicle and may be used onthe work vehicle.

5. The work vehicle shall be equipped with beacons, and the protection vehicles shall be equipped with twohigh-intensity flashing lights mounted on the rear, adjacent to the sign. Protection and work vehiclesshould display flashing or rotating beacons both forward and to the rear.

6. Vehicle-mounted signs shall be mounted with the bottom of the sign, at a minimum height of 1.2 m abovethe pavement. Sign legends shall be covered or turned from view when work is not in progress.

(Rev. 1)


Typical Application 5-17Mobile Operations on Two-Lane Road


(Optional)

Optional Signsfor Short Duration

Operation

ONE LANEROAD

SLOWTRAFFICAHEAD

ROADWORKAHEAD

(Rev. 1)


Lane Closure on Minor Street

1. The traffic control procedure shown is appropriate only for low-volume, low-speed facilities, such aslocal residential streets. With few exceptions, this procedure is not to be used in rural areas. Typicalapplications of traffic control devices on other roadways are shown in Typical Applications 5-21, 5-22,and 5-23.

2. Traffic can regulate itself when volumes are low and the length of the work space is short, thus enablingdrivers to readily see the roadway beyond.

3. Flashing warning lights and/or flags may be used to call attention to the advance warning signs.


Typical Application 5-18Lane Closure on Minor Street

ROADWORKAHEAD

30 m Maximum

A

A

A

A

ROADWORKAHEAD

(Optional)

(Optional)

(Optional)

Note:See Table 5-4

for 'A'.

(Rev. 1)


Detour for One Travel Direction

1. A STREET CLOSED plate may be used in place of ROAD CLOSED.

2. The use of a street name sign mounted with the DETOUR sign is optional. When used, the street nameplate is placed above the DETOUR sign. The plate may have either a white-on-green or a black-on-orange legend.

3. Additional DO NOT ENTER signs may be desirable at intersections with intervening streets.

4. Warning lights may be used on Type III barricades.

5. DETOUR signs may be located on the far side of intersections.

6. Reassurance DETOUR signs should be placed at 400 m + intervals and at major intersections.


Typical Application 5-19Detour for One Travel Direction

ROAD

CLOSED

DETOURAHEAD

DO NOT

ENTER

MAIN ST

SOUTH

DETOUR

ROAD CLO

SEDTO

THRU TRAFFIC

MAIN STDETOUR

MAIN ST

DETOUR

MAIN STCLOSED

DETOUREND

MAI

N S

TDE

TOUR

DETOUR

ROADCLOSEDAHEAD

ROAD

WO

RKAH

EAD

ON

E W

AY

DET

OU

R


Detour for Closed Street

1. Display similar signs and devices for the opposite movement.

2. Use this plan for city streets and for county roads. See Figure TA5-9 for the procedure for detouring anumbered highway.

3. The use of a street name plate mounted with the DETOUR sign is optional. When used, the street nameplate is placed above the DETOUR sign. The plate may have either a white-on-green or a black-on-orange legend.

4. A DETOUR sign with an advance turn arrow may be used in advance of a turn. On multilane streets,such signs should be used.


6. Warning lights may be used on Type III barricades.

7. DETOUR signs may be located on the far side of the intersections.


Typical Application 5-20Detour for Closed Street

A

A

MAIN ST

DETOUR

DETOUREND

DETOUR

ROADCLOSEDAHEAD

A

A

DETOUREND

MAIN ST

DETOUR

DETOUR

DETOURAHEAD

ROADCLOSEDAHEAD

DETOURAHEAD

MAIN STDETOUR

MAI

N S

TDE

TOUR

MAI

N S

TDE

TOUR

MAIN STDETOUR

ROAD CLOSEDTO

THRU TRAFFIC

ROADCLOSED

ROADCLOSED

Note:See Table 5-4

for 'A'.

(Rev. 1)


Lane Closure Near Side of Intersection

1. If the work space extends across the crosswalk, then close the crosswalk using the procedure and devicesshown in Typical Application 5-29.

2. The merging taper may direct traffic into either the right or left lane, but not both. In this typical, a lefttaper should be used so that right-turn movements will not impede traffic.


4. Truck mounted FAS may be used to supplement this package.


Typical Application 5-21Lane Closure Near Side of Intersection

A

A

ROADWORKAHEAD

L

CENTER LANECLOSEDAHEAD


(Rev. 1)


Right Lane Closure Far Side of Intersection

1. For intersection approaches reduced to a single lane, left-turning movements may be prohibited tomaintain capacity for through traffic.

2. The standard procedure is to close on the near side of the intersection any lane that is not carried throughthe intersection. However, when this results in the closing of a right lane having significant right-turningmovements, then the right lane may be restricted to right turns only, as shown. This procedure increasesthe through capacity by eliminating right turns from the open through lane.

3. Where the turning radius is large, it may be possible to create a right turn island using channelizingdevices, as shown. This procedure reinforces the nature of the temporary exclusive right-turn lane andenables a second RIGHT LANE MUST TURN RIGHT sign to be placed in the island.

4. If the work space extends across a crosswalk, then close the crosswalk using the procedure and devicesshown in Typical Application 5-29.


6. Optional treatment see Typical Application 5-23.


Typical Application 5-22Right Lane Closure Far Side of Intersection

(Optional)

ROAD WORKEND

A

TRAFFICMERGE

LEFT

THRU

ROADWORKAHEAD

ROAD WORK

END

ROAD WORKEND

ROADWORKAHEAD

A

(Opt

iona

l)

ROAD

WOR

KEN

D

ARO

ADW

ORK

AHEAD

(Optional)

(Optional)

A ROAD

WO

RKAH

EAD

RIGHT LANE

TURN RIGHT

MUST

A

A

(Optional)

RIGHT LANE

TURN RIGHT

MUST

Note:See Table 5-4

for 'A'.

(Rev. 1)


Left Lane Closure Far Side of Intersection

1. The standard procedure is to close, on the near side of the intersection, any lane that is not carried throughthe intersection. However, when this results in the closure of a left lane having significant left-turningmovements, then the left lane may be converted to a turn bay for left turns only, as shown. By first closingoff the left lane and then reopening it as a turn bay, an island is created with channelizing devices thatallow the LEFT LANE MUST TURN LEFT sign to be repeated on the left, adjacent to the lane that itcontrols.


3. Care should be taken to warn drivers of vision obstructions for left-turning vehicles caused by equipment,material, and work operations in the work zone.


5. Optional see Typical Application 5-22.


Typical Application 5-23Left Lane Closure Far Side of Intersection

(Optional)

ROAD WORKEND

A

A

30 m

ROADWORKAHEAD

ROAD WORK

END

ROAD WORKEND

ROADWORKAHEAD

A

(Opt

iona

l)

ROAD

WOR

KEN

D

ARO

ADW

ORK

AHEAD

(Optional)

(Optional)

A

ROAD

WO

RKAH

EAD

L

LEFT LANECLOSEDAHEAD

LEFT LANE

TURN LEFT

MUST


(Rev. 1)


Half Road Closure Far Side of Intersection

1. For intersection approaches reduced to a single lane, left-turning movements may be prohibited tomaintain capacity for through traffic.

2. The standard procedure is to close on the near side of the intersection any lane that is not carried throughthe intersection. Therefore, the right lane should be closed on the near-side approach. However, if thereis a significant right-turning movement, then the right lane may be restricted to right turns only, as shown.This procedure increases the through capacity by eliminating right turns from the open through lane.

3. Where the turning radius is large, it may be possible to create a right-turn island using channelizingdevices, as shown. This procedure reinforces the nature of the temporary exclusive right-turn lane andenables a second RIGHT LANE MUST TURN RIGHT sign to be placed in the island.

4. If the work space extends across a crosswalk, then close the crosswalk using the procedure and deviceshown in Typical Application 5-29.

5. A buffer space should be used between opposing directions of traffic as shown in this application.

6. There may be insufficient space to place the back-to-back KEEP RIGHT sign and NO LEFT TURNsymbol signs at the end of the row of channelizing devices separating opposing traffic flows. In thissituation, place the no left turn symbol sign on the right and omit the KEEP RIGHT sign.

7. Flashing warning lights and/or flags may be used to call attention to advanced warning signs.


Typical Application 5-24Half Road Closure Far Side of Intersection

(Optional)

ROAD WORKEND

TRAFFICMERGE

LEFT

THRU

ROADWORKAHEAD

ROAD WORK

END

ROAD WORKEND

ROADWORKAHEAD

A

(Opt

iona

l)

ROAD

WOR

KEN

D

A

ROAD

WO

RKAHEAD

(Optional)(O

ptional)

A ROAD

WO

RKAH

EAD

RIGHT LANE

TURN RIGHT

MUST


A

A

A

A

A

L

1/2 L

Buffer Space(Optional)

(Opt

iona

l) (Optional)

(Optional)

Interim Lane Lines(Optional)

Note:See Table 5-4for 'A', 'L' andBuffer Space.

(Rev. 1)


Multiple Lane Closures at Intersection

1. The standard procedure is to close on the near side of the intersection any lane that is not carried throughthe intersection. Therefore, the left through lane is closed on the near-side approach. The LEFT LANEMUST TURN LEFT sign is placed in the median to deter through traffic from entering the left turn bay.


3. If the left-turning movement that normally uses the closed turn bay is small and/or the gaps in opposingtraffic are frequent, left turns need not be prohibited on that approach.



(Rev. 1)

Typical Application 5-25Multiple Lane Closures at Intersection

(Optional)

ROAD WORK

END

A

ROADWORKAHEAD

1/2 L

A

TRAFFICMERGERIGHT

THRU

ROAD

WO

RKAHEAD

ROAD WORKEND

ROAD

WOR

KEN

D

ROADWORKAHEAD

A

(Opt

iona

l)

ROAD WORKEND

(Optional)

(Optional)

AA

1/2 L

L

A

LEFT LANE

TURN LEFT

MUST

(Optional)


ROAD

WO

RKAH

EAD


Closure in Center of Intersection

1. Prohibit left turns as required by traffic conditions. Unless the streets are wide, it may be physicallyimpossible to turn left, especially for large vehicles.

2. A minimum of six channelizing devices shall be used for each taper.

3. For short-duration work operations, on low speed streets, the channelizing devices may be eliminatedif a flashing or revolving yellow light is displayed in the work space.

4. A high-level flag tree should be placed in the work space if there is sufficient room.

5. Flashing warning lights and/or flags may be used to call attention to advanced warning signs.


Typical Application 5-26Closure in Center of Intersection

(Optional)

ROAD WORKEND

ROADWORKAHEAD

ROAD WORK

END

ROAD WORKEND

ROADWORKAHEAD

(Opt

iona

l)

ROAD

WOR

KEN

D

ROAD

WO

RKAHEAD

(Optional)

(Optional)

A

ROAD

WO

RKAH

EAD

1/2 L

3 m Min.

A

1/2 L3

m M

in.

3 m Min.

1/2 LA

3 m M

in.

1/2 L

A


(Rev. 1)


Closure at Side of Intersection

1. For low traffic volumes and intersecting two-lane streets, one flagger positioned in the center of theintersection may suffice.

2. For high traffic volumes or when a four-lane street is involved, additional flaggers or law enforcementpersonnel should be considered.

3. A ONE-LANE ROAD AHEAD sign may also be necessary to provide adequate advance warning.

4. The situation depicted can be simplified by closing one or more of the intersection approaches. If thiscannot be done, and/or when capacity is a problem, consideration should be given to diverting throughtraffic to other roads or streets.



Typical Application 5-27Closure at Side of Intersection

(Optional)ROAD WORK

END

ROADWORKAHEAD

ROAD WORK

END

ROAD WORKEND

ROADWORKAHEAD

(Opt

iona

l)

ROAD

WOR

KEN

D

ROAD

WO

RKAHEAD

(Optional)

(Optional)

A

ROAD

WO

RKAH

EAD

A

A

L

LA

A

A

A

30 m Max.

A


(Rev. 1)


Sidewalk Closures and Bypass Walkway

1. Additional advance warning may be necessary.

2. Only the traffic control devices controlling pedestrian flows are shown. Other devices may be neededto control traffic on the streets. Use lane closure signing or ROAD NARROWS signs, as needed.

3. Street lighting should be considered.

4. For nighttime closures, Type A flashing warning lights may be used on barricades supporting signs andclosing walkways. Type C steady-burn lights may be used on channelizing devices separating thetemporary walkway from vehicular traffic.

5. Where high speeds may be anticipated, use a barrier to separate the temporary walkway from vehiculartraffic.

6. Signs may be placed along a temporary walkway to guide or direct pedestrians. Examples include KEEPRIGHT and KEEP LEFT signs.


Typical Application 5-28Sidewalk Closures and Bypass Walkway

ROADWORKAHEAD

Pedestrian Detour

SIDEWALKCLOSED

SIDEWALK CLOSED

USE OTHER SIDESIDEWALK CLOSED

USE OTHER SIDE

ROADWORKAHEAD

Walkway Provided

PARKINGANY TIME

NOPARKINGANY TIME

NO

(Optional)

(Optional)


Crosswalk Closures and Pedestrian Detours

1. Only the traffic control devices controlling pedestrian flows are shown. Other devices may be neededto control traffic on the streets. Use lane closure signing or ROAD NARROWS signs, as needed.

2. Street lighting should be considered.

3. For nighttime closures, Type A flashing warning lights may be used on barricades supporting signs andclosing walkways. Use Type C steady-burn lights on channelizing devices separating the work spacefrom vehicular traffic.

4. Pedestrian traffic signal displays controlling closed crosswalks should be covered or deactivated.

5. Parking should be prohibited in advance of midblock crosswalks.

6. Midblock crosswalks should be avoided when possible.


Typical Application 5-29Crosswalk Closures and Pedestrian Detours

InterimMarkings forCrosswalk Lines,Cross-hatchingOptional

ROAD

WO

RKAHEAD

ROADWORKAHEAD

SIDE

WAL

K C

LOSE

D

CROS

S H

ERE

AHEAD

CROSS HERE

SIDEWALK CLOSED

SIDEWALKCLOSED

SIDEWALK CLOSED

USE OTHER SIDE

SIDEWALK CLOSED

USE OTHER SIDE

(Opt

iona

l)

PEDE

STRI

ANCR

OSSW

ALK(O

ptional)

PEDESTRIANCROSSW

ALK

(Rev. 1)


Interior Lane Closure on Multilane Street

1. The closure of the adjacent interior lane in the opposing direction may not be necessary, depending uponthe activity being performed and the work space needed for the operation.


3. This procedure applies to low-speed, low-volume urban streets.

(Rev. 1)


Typical Application 5-30Interior Lane Closure on Multilane Street

or

(Optional)

A

A

ROADWORKAHEAD

(Optional)

L

A

A

ROADWORKAHEAD

L


or



(Rev. 1)


Lane Closure on Streets with Uneven Directional Volumes

1. The illustrated procedure would be used only when the traffic volume is such that two lanes of trafficmust be maintained in the direction of travel for which one lane is closed. The procedure may be usedduring a peak period of traffic and then changed to provide two lanes in the other direction for the otherpeak.

2. The traffic control devices shown are appropriate for an urban street. Additional advance warning maybe necessary.

3. A buffer space should be used in the activity area and to separate opposing traffic.

4. Conflicting pavement markings should be removed for long-term projects. (See Section 5-06.3.) Forshorter-term projects when this is not practicable, the channelizing devices in the area of conflict shouldbe placed at a maximum spacing of 3 meters. Interim markings should be installed where needed.

5. For higher speeds, add a LEFT LANE CLOSED [distance] sign for traffic approaching the lane closure,as shown in Typical Application 5-32.

6. If the lane shift is short and has sharp curves (50 km/h or less), Reverse Turn signs should be used.

7. Where the shifted section is long, use a Reverse Curve sign to show the initial shift and a second one toshow the return to the normal alignment. If the shift involves a short runaround, a symbol showing back-to-back reverse curves may be used. As an alternative side-by-side arrows may be used displaying onearrow for each lane. A supplementary plate stating ALL LANES THRU may be used to emphasize thepoint that no lanes are closed.


Typical Application 5-31Lane Closure on Streets with Uneven Directional Volumes

A

A

ROADWORKAHEAD

L

L

A

ROADWORKAHEAD

1/2 L

30 m

BufferSpace

A

(Optional)

BufferSpace

XXMPH

(Optional)

XXMPH

(Optional)


(Rev. 1)


Half Road Closure on Multilane High Speed Highways

1. The traffic control devices shown are appropriate for a high speed highway.

2. Pavement markings no longer applicable shall be removed or obliterated as soon as practicable. Interimmarkings shall be used as necessary.

3. Warning lights may be used to mark channelizing devices at night as needed.

4. For intermediate-term situations, when it is not feasible to remove and restore pavement markings, thechannelization must be made dominant by using a very close device spacing. This is especially importantin locations of conflicting information, such as where traffic is directed over a double yellow centerline.In such locations a maximum channelizing device spacing of 3 meters is recommended.


Typical Application 5-32Half Road Closure on Multilane High Speed Highways

ROAD WORKEND

L

A

ROADWORKAHEAD

1/2 L Min.

1/2 L Min.

A

ARIGHT LANE

CLOSEDXXXX FT

XXMPH

(Optional)

or

L

A

ROADWORKAHEAD

A

A

LEFT LANECLOSEDXXXX FT

or

1/2 L Min.

ROAD WORKEND

Interim WhiteEdge Line

Interim YellowCenter Line

(Optional)

(Optional)

(Optional)

(Optional)


(Rev. 1)


Lane Closure on Divided Highway

1. This procedure also applies when work is being performed in the lane adjacent to the median on a dividedhighway. Under these conditions, LEFT LANE CLOSED signs and the corresponding Lane Reductionsymbol signs shall be used.

2. When a side road intersects the highway within the temporary traffic control zone, additional trafficcontrol devices shall be erected, as needed.

3. Longitudinal dimensions may be adjusted slightly to fit field conditions.

4. All vehicles, equipment, workers, and their activities should be restricted to one side of the pavement.


Typical Application 5-33Lane Closure on Divided Highway

*Signs shown inmedian optional.

ROAD WORKEND

ROADWORKAHEAD

1/3 L (Optional)

(Optional)

or

30 m (Optional)

150 m

InterimWhite Edge Line

Long-Term

RIGHT LANECLOSEDAHEAD

(Optional)

*

*

*

ROADWORKAHEAD

1/3 L (Optional)

or

150 m

Short-Term


Truck-MountedCrash Cushion

(Optional)

Trailer or TruckFlashing Arrow Sign

(Optional)

BufferSpace

L

A

A

A

*

*

*


ROAD WORKEND

(Optional)

(Rev. 1)


Lane Closure with Barrier


2. The use of a barrier should be based on the need determined by an engineering analysis.

3. The layout of the barrier should prevent vehicles from impacting the ends of the barrier. To accomplishthis, the taper and end should be treated as given in chapter 9 of the ASSHTO Roadside Design Guide(RDG) or the Caltrans Standard Plans. Example treatments are connecting to an existing barrier,attaching a crashworthy terminal such as a crash cushion, or flaring away to the edge of the clear zone.

4. An interim white edge line should be installed from the start of the taper to a point beyond the work zone,rejoining the permanent edge line.

5. The barrier shall not be placed along the merging taper. The lane shall first be closed using channelizingdevices and pavement markings. The barrier is then placed on a flare beginning beyond the downstreamend of the merging taper.

6. Refer to Caltrans Standard Plans for barriers.


Typical Application 5-34Lane Closure with Barrier

ROAD WORKEND

ROADWORKAHEAD

450 m

(Optional)

(Optional)

A

ROAD WORKEND

ROADWORKAHEAD

(Optional)

Interim WhiteEdge Line


A

A

L

3 mMin.

(Optional)

Barrier Lights(Optional)

*

*

*

*Signs shown inmedian optional.

Buffer Space


(Rev. 1)


Mobile Operation on Multilane Road

1. Vehicles used for these operations should be made highly visible with appropriate equipment, such asflashing lights, rotating beacons, flags, signs, or flashing arrow signs (FAS).

2. Protection vehicle #1 should be equipped with an FAS. An appropriate lane closure sign should be placedon protection vehicle #1 so as not to obscure the FAS.

3. Protection vehicle #2 should be equipped with an FAS and truck-mounted crash cushion.

4. Protection vehicle #1 should travel at a varying distance from the work operation so as to provideadequate sight distance for traffic approaching from the rear.

5. When adequate shoulder width is not available, protection vehicle #1 should be eliminated.

6. On high-speed roadways, a third protection vehicle should be used; vehicle #1 on the shoulder (ifpossible), vehicle #2 in the closed lane, and vehicle #3 in the closed lane.

7. Flashing arrow signs shall be, as a minimum, Type B, 1800 by 900 mm (Figure 5-9, Section 5-05.4).

8. Work should normally be done during off-peak hours.


Typical Application 5-35Mobile Operation on Multilane Road

1

2

3

ChangableMessage Sign

(Optional)




(Optional)

(Rev. 1)

Traffic Controls for Construction and Maintenance Work · PDF fileTRAFFIC MANUAL CHAPTER 5 ......

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