Historical Accuracy of Traffic Forecasts and Induced Travel

The Bipartisan Infrastructure Law (BIL) charges the U.S. Department of Transportation with fulfilling certain requirements to support more accurate travel demand forecasting. Those requirements include developing a study that accounts for the historical accuracy of travel demand forecasting and producing best practices or guidance for states and MPOs to support enhanced future accuracy. These requirements are both statutory and aligned with USDOT strategic objectives on climate change, safety, and scientific integrity. USDOT OST-R proposes the following activities to be executed by UC Davis-led Center for Emissions Reduction, Resiliency, and Climate Equity in Transportation (CERRCET) to further develop travel demand modelling research and public information: Conduct a short-term study of MPOs and States’ historical accuracy in travel demand forecasting. BIL (PL 117058 Sec. 11205 (b)) requires that USDOT complete a study that considers retrospectively the accuracy of previous travel demand forecasting and data using a representative sample of states and MPOs. The study must consider travel counts, travel mode share and public transit ridership, and vehicle occupancy measures. UC Davis team will execute a study in fulfillment of the statutory requirement on behalf of USDOT and publish in a refereed journal. This study will be published on the USDOT website and referred to in the development of further guidance. Deliverable: Study on historical accuracy of travel demand modelling in partial fulfillment on BIL requirement Timeline: December 2026