Review of TPB Travel Modeling Procedures

Transportation Research Board (TRB)

At its April 17, 2002 meeting, the TPB approved a process for conducting a review of the region's travel modeling procedures. The process called for the TPB to engage a respected non-partisan organization such as the Transportation Research Board (TRB), to appoint the members of the peer review panel and oversee the review process. A request was formally made to the TRB on May 8, 2002 in a letter from then TPB Chair, Phil Mendelson. The TRB accepted this task and began its analysis of the TPB modeling procedure in January 2003. On September 8, 2003 the TRB submitted its first letter report and on May 10, 2004 the TRB concluded its analysis with the submission to TPB of its second and final letter report. TPB staff provided detailed comments on each of the TRB reports in letters of September 8, 2003 and May 13, 2004 respectively.

The following materials document the TRB review and TPB staff comments:

• First letter report from TRB - September 8, 2003
• TPB staff comments on TRB first letter report of TPB models - September 8, 2003
• Descriptions of Proposed Work Elements for the TPB Models Development Program - December 24, 2003
• Appendices to Descriptions of Proposed Work Elements - December 24, 2003 (2 MB)
• Second letter report from TRB - May 10, 2004
• TPB staff comments on TRB second letter report of TPB models - May 13, 2004

Beginning in FY 2006, the TPB has had a task-order consulting contract to scan the best practices in travel demand forecasting across the U.S.  The scope of work for this project includes three components:

• Attend all meetings of the TPB Travel Forecasting Subcommittee and other committees as appropriate;
• Provide written guidance to the TPB staff on specific models development issues raised at either the Travel Forecasting Subcommittee or other forums, drawing upon knowledge of travel demand modeling practice in other MPOs;
• Conduct research focused on specific modeling issues raised by TPB staff.

For fiscal years 2006, 2007, and 2008, the contract was awarded to Vanasse Hangen Brustlin, Inc. (VHB).  Beginning in FY 2009, the contract was awarded to Cambridge Systematics, Inc.  The following documents have been produced or are under development:

FY 2006

• Review of Managed Lane Forecasting Techniques - September 22, 2006
• Review of MPO External Trip Forecasting Methods - September 22, 2006
• Review of Experience with Equilibrium Assignment - September 22, 2006
• Review of Current Use of Activity-Based Modeling - September 22, 2006

FY 2007

• Review of FTA Summit Software - November 16, 2007
• Current Use of Traffic Simulation and Dynamic Traffic Assignment (DTA) Models by MPOs - November 16, 2007
• State of the Art in Equilibrium Traffic Assignment - November 16, 2007
• State of the Practice and State of the Art of Modeling Peak Spreading - November 16, 2007
• Use of Cutlines for Model Validation - November 16, 2007
• Use of Feedback Loops Coupled with Nested Logit Mode Choice Models - November 16, 2007

FY 2008

• Estimating the Impact of Exurban Commuters on Travel Demand - June 30, 2008
• Expanded Evaluation of Peak Spreading - June 30, 2008

FY 2009 (Under development)

• Fuel Prices in Travel Models
• Recommended Approach to Near-Term Model Enhancements
• Framework for Before-and-After Study of HOV Network Effects Due to New HOT Lanes

The reports listed above can also be found on the “AMPO Travel Modeling Work Group” webpage, which also lists similar reports for other MPOs.