1 / 36

Examination of a Quality Control Forecast Model for Transit New Starts Projects

Examination of a Quality Control Forecast Model for Transit New Starts Projects. Arash Mirzaei P.E. Huimin Zhao Ph.D., P.E. North Central Texas Council of Governments. 11 th TRB National Transportation Planning Application Conference. May 9 th , 2007. Acknowledgement. Ken Cervenka, NCTCOG

candy
Download Presentation

Examination of a Quality Control Forecast Model for Transit New Starts Projects

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Examination of a Quality Control Forecast Model for Transit New Starts Projects Arash Mirzaei P.E. Huimin Zhao Ph.D., P.E. North Central Texas Council of Governments 11th TRB National Transportation Planning Application Conference May 9th, 2007

  2. Acknowledgement • Ken Cervenka, NCTCOG • Jim Ryan, FTA • Nazrul Islam, FTA • DCTA Project Team

  3. Disclaimer • Work in Progress • Preliminary Results and Conclusions

  4. Outline • Objectives • Mode Choice Model at NCTCOG • SUMMIT for New Starts • Incremental Logit Model • Transit Skim • Comparison Results and Lessons Learned

  5. Objectives • To be Compatible with FTA Guidance and Recommendations • To Test the Semi-Independent Ridership Forecasts (QC Model) for New Starts • To Compare the User Benefits between a Locally Developed Transit Skim/Mode Choice Model and a Quality Control Model

  6. Mode Choice Model at NCTCOG • Model Structure • Nested Logit Models for HBW and HNW • A Multinomial Logit Model for NHB • Stratified Sample Data • 1996 Household Travel Survey • 1996 FWTA On-Board Survey • 1998 DART On-Board Survey

  7. Validation: YR1999 1999 Rail Station Ons and Offs (Weekday)

  8. Comparison of Daily TRE Ridership: 2005 Observed vs. NCTCOG Model 2005 NCTCOG Model Validation: YR2005

  9. 2005 TRE Rail Station Ons plus Offs (Weekday) Validation: YR2005 (cont)

  10. Mode Choice Model (cont.) • Nesting Structure for HBW

  11. NCTCOG Mode Choice Model Structure • Nesting Structure for HNW

  12. Standard Nesting Structure in SUMMIT

  13. Coefficient Comparison

  14. P P1 ΔP P0 ΔX X X1 X0 Gradient ΔP/ ΔX Quality Control Model • FTA Recommends the Quality Control Alternative for a Commuter Rail New Starts Project in DFW Area • Incremental Logit Model

  15. QC Model Coefficients

  16. Impedance Weight for Transit Skim The Weights are Consistent with Mode Choice Model Coefficients

  17. Start Base Case Transit System Alternative Case Transit System Transit Skim Using FTA Recommended Parameters NCTCOG Travel Demand Model Base Skim Matrix Alternative Skim Matrix FTA Coefficients Difference Matrix: Skim Variables, Utilities Base Case Matrix: Transit Trips, Utilities Alternative Case Matrix: Transit Trips, Utilities End QC Model Flow Chart

  18. QC Model Procedure • Run NCTCOG Skim and Mode Choice on Base Case to Obtain Base Case Transit Trips and Utilities • Run Transit Skims on Base Case and Alternative Scenario Using FTA Recommended Weights • Calculate IVTT, OVTT, Fare, as well as Utility Differences between Base and Alternative Transit Skims • Calculate Transit Share Change due to Skim Differences and Obtain the Transit Trips for Alternative Case • Two QC Models are Tested: One with No Rail Constant, One with a 12-minute Rail Constant

  19. Transit Skim Settings • Maximum Trip Cost • Maximum Number of Transfers • Maximum Walk/Drive Time • Maximum Initial/Transfer Wait Time • Combination Factor

  20. Comparison Results

  21. Base: Express Bus

  22. Alternative: Rail

  23. User Benefit Comparison • Tested One Market Segment of HBW Trips: H23WVLTP • Compared Three Scenarios: NCTCOG Model, QC Model with No Rail Constant, QC Model with a 12-minute Rail Constant

  24. User Benefits: NCTCOG Model

  25. User Benefits: NCTCOG Model (cont)

  26. User Benefits: QC Model without Rail Constant

  27. User Benefits: QC Model without Rail Constant (cont)

  28. User Benefits: QC Model with 12-Min Rail Constant

  29. User Benefits: QC Model with 12-min Rail Constant (cont)

  30. Transit Trip Comparison

  31. Transit Walk Trip Differences: NCTCOG Model

  32. Transit Walk Trip Differences: QC Model (No Rail Constant)

  33. Transit Drive Trip Differences: NCTCOG Model

  34. Transit Drive Trip Differences: QC Model with No Rail Constant

  35. Conclusions • QC Model Approach Offers a Level Playing Field to Compare New Start Projects across the Country • Transit Trips and User Benefit from QC Model is Much Less than Those from NCTCOG Model • Though Different in Quantity, We Observed Similar Patterns in Transit Trip Shifts, Especially for Transit Walk Trips, from Both Approaches

  36. Next Steps • More Tests to Confirm the Implementation Procedure • Investigate Transit Skim Differences • Investigate the Impact of Differences in Transit Accessibility between Base and Alternative Cases

More Related