Transportation planning agencies are increasingly seeing the value of dynamic traffic assignment (DTA), a tool for modeling equilibrium traffic flows at a fine time scale across a large spatial area. DTA models are being used in practice to answer policy questions for which the traditional static assignment model is not capable of answering. To fully embrace DTA into the planning process, it must be integrated with the existing travel model. Integrating DTA with an activity-based model provides an accurate, theoretically consistent, state-of-the-art planning framework. However, many agencies do not yet have activity-based models and continue to rely on a traditional four-step model. For these agencies, combining the four-step model with DTA is a cost-effective approach to add detailed temporal dynamics to existing planning processes.

This presentation will focus on how the temporal details of DTA can be used to enhance mode choice modeling when integrating DTA with a traditional four-step model. The Austin, Texas region will be used as a case study and examples will be shown integrating a regional DTA model with the Capital Area Metropolitan Planning Organization (CAMPO) travel model as well as integrating a sub-area DTA model with the CAMPO travel model. DTA is often used for sub-area modeling and integrating a sub-area DTA model with a regional travel model brings up interesting consistency issues that will be explored through this work.