The Strategic Highway Research Program (SHRP2) Project C10B, Partnership to Develop an Integrated, Advanced Travel Demand Model and a Fine-Grained, Time-Sensitive Network, is an important step in the evolution of travel modeling from an aggregate, trip-based approach to a completely dynamic, disaggregate methodology. In this project, an existing disaggregate activity based model is being integrated with an existing traffic simulation model to create a new, completely disaggregate model. Both models are currently implemented using open source software.
SHRP C10B began in the fall of 2009 and will be completed in early 2013. The main product is an integrated model that simulates the complete set of activity and travel choices for each individual in an urban area, including activity type, location, travel mode, time of day, and highway and transit route choices. A unique feature of this model is the simulation of transit vehicles as well as individual person tours using transit.
The development of the new integrated model is complete and has been implemented for the entire Sacramento, California region. While the model produces reasonable results for regional travel patterns and behavior, the true value of the model is its ability to provide analysis results that demonstrate sensitivity to policy variables more accurately than models that use aggregate demand or assignment procedures. This sensitivity is being tested through a series of policy and project tests conducted by the Sacramento Area Council of Governments, the regional MPO, using the new integrated model and their existing activity-based model with aggregate assignment. These tests include analysis of signal coordination, freeway bottlenecks, a new transit line, transit schedule coverage, interchange improvements, and road pricing (HOT lane). The tests, while hypothetical, represent the types of policies and projects that SACOG examines in their regional transportation planning process.
The presentation will discuss the implementation of the model, its use by SACOG for the policy tests, the results of these tests, and the next steps for this type of analysis tool beyond the C10B project.