PSRC is assisting Transportation Northwest (TransNow) at the University of Washington on a research project to develop more usable and accurate truck trip generation methodologies. This will enhance the PSRC truck trip generation process and should enable us to better forecast truck travel and improve freight mobility planning.

Information about truck movements on our transportation system is important for understanding and supporting freight mobility. Unfortunately, there is relatively little information available on how different land uses generate truck trips. Such information is necessary as input into travel forecasting models as well as needed to plan for a range of freight-oriented infrastructure construction projects.

Truck transportation is a derived demand so each truck trip is filling an economic need by linking a resource extraction site, a crop, a manufacturer, a supplier, or an intermodal terminal with a consignee. By using GIS tools, this relationship between a land use that generates trucks trips and truck volumes on roadways could be explored. Such tools that estimate and forecast the relationship between land use and trip generation exist in the passenger planning world but have not been widely applied to freight.

A second objective of this effort is to develop trip rate estimates for specific categories of truck trip generators in the Puget Sound region that are also applicable nationally. The initial focus of the study is to consider the specific truck trip generation rates for grocery stores. Once complete the research will consider home improvement stores and warehouses as further case studies.