TransCAD Modeling At NCTCOG

Ken Cervenka And Arash MirzaeiNorth Central Texas Council Of Governments

For

Tex-ITE Fort Worth MeetingFort Worth, TexasJanuary 20, 2005

Agenda

Model Overview

How To Run The Model

Next Steps

Regional Travel Model Ú Traffic Microsimulation

4,536,010

6,671,351

4,848,237

5,650,339

7,952,0708,503,146

0

1,000,000

2,000,000

3,000,000

4,000,000

5,000,000

6,000,000

7,000,000

8,000,000

9,000,000

10,000,000

1995 2000 2005 2010 2015 2020 2025 2030 2035 2040

Previous Plan Demographics (Mobility 2025 Update) New Plan Demographics (Mobility 2025, 2004 Update)

(Previous Plan)

(New Plan)

Total Population Within The Dallas–Fort Worth Metropolitan Planning Area

Current NCTCOG Model

TransCAD Platform (Windows)

5,000 Square Miles / 4,874 Zones

Fully-Batched / Graphical User InterfaceBut Humans Must Still Analyze/Interpret The

Results--And Make The Decisions!

Creation Of 4,874-Zone Structure

Start With Year 2000 Census Block LayerGround Truth RectificationSome Block Splits (e.g., DFW And Love Field Airport)76,336 Blocks Aggregated To 6,399 zonesAdd 61 External Station “Tiny Circle” Zones = 6,460 Total Zones

Aggregate The 6,460-Zone Layer= 4,813 Internal Zones + 61 External Station Zones= 4,874 TransCAD Model Zones

The “Practicality”Of Real-World Modeling

Actual Scope Of Human Behavior ÚModel Scope– All Person Trips gMotorized Person Trips– Travel Tours g HBW, HNW, NHB, And Truck Trip

Purpose Categories– All Occupations g Basic, Retail, And Service Jobs– All Households g Income And Household Size Categories

(Plus Auto Ownership Breakdowns)– All Streets g Non-Local Streets

Individual Data Ú Aggregate Data (Zones)

Four-Step Modeling Process

TRIP GENERATION

TRIP DISTRIBUTION

MODE CHOICE

ROADWAY ASSIGNMENT

TRAVEL TIMECONVERGENCE

TRANSIT ASSIGNMENT

NO

YES

ZONE LAYERDEMOGRAPHIC INFORMATION

ROADWAY NETWORK

TRANSIT NETWORK

LO

OP

ROADWAY SKIMS

TRANSIT SKIMS

INPUT

PROCESS

DECISION

Trip Generation

GISDK Macro LanguageSeven “Regular” Internal-Internal Trip Purposes4 HBW, 1 HNW, 1 NHB, And 1 Truck

InputsPopulation, Households, Income, And Basic/Retail/Service JobsSpecial Generators (Shopping Malls, Colleges, Hospitals, Airports)

Trip Distribution

Gamma-Format Gravity Model (7 Purposes)Four HBW Groups (Income Quartiles) – AM PeakHNW (Non-Airport) – OffPeakNHB (Non-Airport) – OffPeakTrucks (Vehicles With Six Or More Tires) – OffPeak

Base Year Trip Table Factoring (6 Purposes)HNW And NHB Airport TripsFour External-Related Auto/Truck Trips

Mode Choice Inputs

Auto Travel (AM Peak And Offpeak)Roadway Travel TimeRoadway Length (Operating Cost)Daily Parking Cost

Transit Travel (AM Peak And Mid-Day Offpeak)In-Vehicle Transit Travel Time (Includes Dwell)Walk (Or Drive) Access TimeWalk Transfer And Egress TimeInitial And Transfer Wait TimeTransit FareMarket Segment And Area Type Constants

Transit Assignment

Four Multi-Path (TransCAD Pathfinder) Production-Attraction Assignments

For All HBW Transit TripsPeak Transit-Initial Drive Access (Park-and-Ride)Peak Transit-Initial Walk Access (No Park-and-Ride)

For All HNW And NHB Transit TripsOffpeak Transit-Initial Drive Access (Park-and-Ride)Offpeak Transit-Initial Walk Access (No Park-and-Ride)

Traffic Assignment

User Equilibrium Generalized Cost (Three 30-Iteration Assignments)

A.M. Peak (6:30a – 8:59a: 2.5 hours)P.M. Peak (3:00p – 6:29p: 3.5 hours)OffPeak (18 hours)

Four Vehicle Classes Loaded SimultaneouslyDrive Alone (Sees HOV-Toll Lanes As Tolled)Shared-Ride (Sees All HOV Lanes As Free)Shared-Ride (Doesn’t See Any HOV)Trucks (Vehicles With 6 Or More Tires)

Zone StructureCurrently, 4,874 Internal And External TZSTSZs Are Nested Within 720 RAA zonesMaintained In A TransCAD Area Layer (TSZ.DBD)User Can Group TSZs Into Different Subareas For Reporting

Trip GenerationConvert Demographic Data To Trip Productions And AttractionsTSZ-Level Input And Output Data In DBF FormatRun Time < 5 Minutes

Roadway Network Creation

Roadway Network Editing Currently Done With ArcInfo (Unix)ArcInfo File Converted To TransCAD LayerRun Time < 15 Minutes

Approach Links

Approach Links Added In TransCAD EnvironmentTransferred From Existing LayerAbout 10,000 Approach Links

Run Time < 30 Minutes

Roadway Preparation

Link Capacities

Initial Link Travel Times

Toll Cost Adjustments

Run Time = 30 Minutes

Transit Coding

Done In TransCAD EnvironmentMode, Headway, And Pulse DesignationsPark-And-Ride Locations Coded Transit Network Can Be Transferred Between Roadway Networks

AUTOMATED NETWORK CONVERSION

Full Model Run

Roadway/Transit Skimming, Mode Choice, Time-Of-Day MatrixManipulations, And Traffic/Transit Assignments

Run Time With No Feedback = 13 HoursRun Time With Two Feedbacks = 27 HoursStorage Space Per Run = 31 GB

Optional “Partial” Model Runs

Test Transit AlternativesHold Person Trip Tables And Roadway Skims FixedRun Transit Skims, Mode Choice, And Transit AssignmentRun Time = 5 HoursStorage Space Per Run = 15 GB

Test Roadway AlternativesHold Vehicle Trip Tables FixedHold Transit Skims FixedRun Time = 6 To 10 Hours

Standard Automated Reports

TransitAfter Coding/Before Assignment

Route Level (VMT, Stops)Mode Level (VMT)

After AssignmentSystem LevelRoute LevelStop Level

RoadwayBefore Assignment (Summary Of Coded Network)After Assignment (Model Results)

What Happens Next For NCTCOG

Model Applications TrainingNCTCOG Staff / Other AgenciesCertify Consultants? Or Let Them Run Free?

Document The “Whys” Of Our Model Assumptions

More (And More) Automated Output SummariesTables, Graphs, Thematic Maps

Integrated GIS Database EnvironmentMulti-Year Roadway/Transit Network Coding

Agency's "Master Street Layer"

Covers 16-County NCTCOG Area

Example: Blue Street Links Are Extracted To Travel Model Links

Single-Point Intersection

Example: Future-Year Interchange

Network Coding EnvironmentAgency's

ArcGIS LayerTransCAD Multi-

Year Network

Roadway/Transit Corridor Study

Agency's ArcGIS Layer

TransCAD Multi-Year Network

Alternatives

Agency's ArcGIS Layer

TransCAD Multi-Year Network

Final Recommendations

UpdatesUpdates

Updates

Checks

Checks

Updates

Checks

(Do Once)(Frequently)

GIS Database Integration

TransCAD Multi-Year Network

ArcGIS TIP/AQ Database and

Layer

ArcGIS Multi-Year Integrated

Layer

Other Databases/LayersTraffic Counts (Access)ITS Data (SQL)Skycomp Data (Access)GPS-Based Travel TimesAccidentsAt-Grade RR CrossingsIntersection Details

Export

Web-BasedInteractiveDisplays

What Happens Next (Cont.)

Destination Choice/Gravity Model Comparisons

Expanded Travel Model Area10-12 Counties8,000+ Square Miles (>6,500 Zones)

Update Or Replace Land Use Model (Metropilus)

Coordination With TxDOT Statewide Analysis Model

The Texas StatewideAnalysis Model

Covers Entire State, Plus “Buffer” Counties4,742 Model Zones1998 Calibration/Validation (19.8 Million People In State)2025 Forecast (31.2 Million People)

Single Multi-Year Coded NetworkEach Record Contains Separate Link Attributes For 1998 And 2025

(Lanes, Speed Limit, Estimated Congested Time, Capacity)

The Texas StatewideAnalysis Model – Trip Types

Passenger TravelVehicle Trips By AutoPerson Trips By AirPerson Trips By Rail (AMTRAK)Placeholder For High-Speed Rail

Freight TravelCommodities By TruckCommodities By RailCommodities By Water

What Happens Next (Cont.)

Model Sharing (For Traffic Assignment)Concern: Quality/Integrity Of Consultant Forecasts12 Origin-Destination Vehicle Trip Tables (3 TOD X 4 Classes)Roadway Network/Zonal DataTraffic Assignment Documentation

Sensitivity Tests Of Activity-Based Model (CEMDAP)UT-Austin, NCTCOG, TTI, Texas DOT

Regional Travel Model Ú Subarea Microsimulations

Regional Model

Sub-Area Cut Off Links And Nodes

Converting the Demand

4874 x 4874 demand matrix

156 x 156 demand matrix

Microsimulation Model