Technical Memo 1:
Travel Model Terminologies and Review of Model Documentation

Initial tasks of the project involve the collection and review of current model documentation with an emphasis on the models' capacities for addressing land use and multimodal issues. A working report has been drafted as an initial project task. A summary is provided here and the full report of the current version is available for download by TAC members only.

Summary of Tech Memo 1:

This review looks at current modeling practice in California and identifies modeling applications that are designed to quantify the effects of smart growth on regional and local travel demand. The review begins with a brief introduction of the methodology of travel demand modeling and is followed by the identification of shortcomings of current methodology regarding its responses to smart growth strategies. The introductory materials offer the necessary terminologies that are the basis of travel demand models. Documentations of selective models used in California are then reviewed. The review is intended to be comprehensive with a focus on the models' ability to reflect smart growth principles. Models reviewed come from MPOs and county governments. The selection is based on a combination of factors: geographic locations, urban forms/development patterns, use of travel models for regional transportation planning, and the applications of smart growth and transit-oriented development strategies in the communities. Another important criterion in selecting the models for review is the development horizon. Models reviewed here are relatively new (developed after 2000). Older models, often termed legacy systems, were developed before smart growth strategies were proposed. They usually do not have the necessary functions for reflecting the strategies.

Results of this review serves as the foundation for future research activities of this project. Based on results of the review, attempts will be made to collect the actual models reviewed. Numerical experiments and sensitivity tests will be set up to evaluate the performance of the models and to validate the results reported. In the event that shortcomings of these innovative, smart-growth-sensitive models are identified, then recommendations for potential model improvement will be identified as part of the final results of this study.

The models reviewed include:

1. San Diego Association of Governments (SanDAG)
2. Santa Barbara County
3. Santa Clara Valley Transportation Authority
4. Contra Costa County
5. San Joaquin Valley Growth Response Study Phase III
6. Orange County Transportation Authority's OCTAM Model
7. City of Irvine Transportaiton Analysis Model

Please note that, although there have been several studies of land use/transportation modeling in the Sacramento metropolitan area, review of these models is not considered as part of this study. A parallel Caltrans-sponsored research project being conducted by UC Davis focuses on regional transportation and land use models. That project considered LU/T model application in the Sacramento region.

Documentation pertains to strategies of the Metropolitan Transportation Commission (MTC) for integrating smart growth in the model is also reviewed ("Incorporating the Effects of Smart Growth and Transit Oriented Development in San Francisco Bay Area Travel Demand Models: Current and Future Strategies"). The strategies can be potentially applied to the local travel models that are based on MTC models.

A preliminary assessment of the strength and weakness of the reviewed models in reflecting the effectiveness of smart growth and transit oriented development is provided as the conclusions of this report. Verification of the assessment requires seeing the model in action by running numerical evaluation with the actual models.