NCTCOG And “Next Generation” Modeling Ken Cervenka, P.E., AICP North Central Texas Council Of Governments For AMPO Travel Modeling Work Group Meeting Kansas City, Missouri September 28, 2004

Agenda Current Modeling Environment Multi-Year Network Coding Next Steps—Near Term Next Steps—Taking The Plunge

Total Population Within The Dallas – Fort Worth Metropolitan Planning Area

Four-Step Modeling Process TRIP GENERATION TRIP DISTRIBUTION MODE CHOICE ROADWAY ASSIGNMENT TRAVEL TIME CONVERGENC E TRANSIT ASSIGNMENT NO YES ZONE LAYER DEMOGRAPHIC INFORMATION ROADWAY NETWORK TRANSIT NETWORK LOOP ROADWAY SKIMS TRANSIT SKIMS INPUT PROCESS DECISION

Market Segmentation To Account For Differences In Commuter Behavior Segmentation Basis (6 HBW And 6 HNW) –Household Income (3) Low Medium High –Vehicle Availability For A Household (2) Vehicles Less Than Persons Vehicles Greater Than Or Equal To Persons

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 Simultaneously Drive 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)

Multi-Year Network Concept One Link/Node Layer And One Transit Route Layer For ALL Years Contains ALL Streets Essentially A 25-Year TIP! Travel Model Network Extracted From All Streets Layer Link And Route Selections Based On Start And End Date Fields Local And Non-MPA Street Links Excluded

Example: Blue Street Links Are Extracted To Travel Model Links

Agency's "Master Roadway Layer" Covers 16-County NCTCOG Area

2003 Digital Aerial Photos (Six Inch)

Example: Future-Year Interchange

Single-Point Intersection

Network Coding Environment

GIS Database Integration

Some Tough Issues True Multi-Year Coding Is A Complex Environment But Allows For Greater Consistency/Quality Control Between Travel Model Years (And With TIP) Traffic Counts And Detailed Roadway Data (Including Traffic/Transit Projections): Should We Put Everything On the Web? Who Pays For The Initial Collection Costs? Is Everything Free To The End User? Should We Be Concerned About Possible Misuse?

Taking The Plunge: Activity-Based (AB) Modeling Maybe It Is “Put Up Or Shut Up” Time! We Must Find Out Where Things Stand Rigorous Sensitivity Tests Of Estimated Models NCTCOG Can Test CEMDAP (UT-Austin/DFW Data) Other Agencies Can Test Other AB Model Brands Major Issues For Resolution: Current Worthiness And Readiness Of AB Models Spatial/Temporal Transferability Of Formulations/Estimations If Not Ready: Realistic Costs And Timeframes For Improvements

Simple Sensitivity Tests (Examples) Global Increase/Decrease Of Input Variables Area-Specific Increase/Decrease Of Input Variables Check Local/Regional Change In Travel Patterns Check Local/Regional Change In Person Miles Perform Same Tests With Implemented Four-Step Model

If Current Activity-Based Model Formulations/Estimations Aren’t Ready For The Real World: Form An MPO (Or MPO/DOT) Consortium Pooled Funding/Staff Resources Pooled Survey Data And Network Skims Identify Realistic Project Scope Competitive Procurement Of University/Consultant Team Independent Review Panel/Paid Workgroup Team Quarterly Meetings For Sponsors To Measure Progress Public Exposure May Help Keep Everyone Honest/Objective Must Deal With Proprietary Software Issues

Desired Results For Pooled Funding Effort Applied Research Conducted In An Orderly Fashion Does A New Theory/Latest Fad “Smell” Right? Each Model Calibration/Validation Effort Builds Upon Successes/Failures Of Previous Implementations Provide Support For New Basic Research Discourage A Start-From-Scratch Mentality

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