Statewide and megaregion travel demand models are used to help formulate plans and policies, evaluate and prioritize projects and programs, and assess the economic and social impacts of major transportation investments. This synthesis documents the state of the practice in applying these types of travel demand models as well as the challenges and emerging trends. The investigation focused issues such as the motivation for and capabilities of statewide and megaregion models, options for extending them and challenges states face doing so, data requirements, how they are used and integrated with other models, institutional constraints, and emerging trends and methods. The findings suggest that there much to be encouraged about in the results. Statewide models have flourished and have significantly expanded detail and capabilities compared with those just a decade ago. These advances occurred despite lingering and significant gaps in data and understanding of several long-distance person and visitor travel and how it is changing over time. Findings also show there is a wide diversity of demands placed upon such models and that investing in data collection is critical, with most states appearing eager to leverage big data for extending their models. Understanding freight and its economic linkages and impacts was cited as the primary or important motivation for statewide models. Freight analytics are also important in urban models, but to nowhere near the extent they are at the statewide level. The considerably more sophisticated mode choice models used for high-speed rail forecasting, as well as the data used to develop them, are finding their way into statewide models. The transition path for improved person travel models is well established, whether the goal is to improve existing models or move to advanced travel models. There is no gradual transition for freight modeling, however. A much larger investment in data and model development is required to create activity-based freight models, which limits the number of states that can afford them.     «

Statewide and megaregion travel demand models are used to help formulate plans and policies, evaluate and prioritize projects and programs, and assess the economic and social impacts of major transportation investments. This synthesis documents the state of the practice in applying these types of travel demand models as well as the challenges and emerging trends. The investigation focused issues such as the motivation for and capabilities of statewide and megaregion models, options for extending...     »