TransCAD Modeling At NCTCOG...The “Practicality” Of Real-World Modeling Actual Scope Of Human...
Transcript of TransCAD Modeling At NCTCOG...The “Practicality” Of Real-World Modeling Actual Scope Of Human...
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
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
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