Assembling and Processing Freight Shipment Data: Developing a GIS-Based Origin-Destination Matrix for Southern California Freight Flows

This research focuses on establishing a systematic non-survey-based method for developing an origin-destination (OD) matrix of freight flows based on secondary data sources. The estimated freight flows and concurrent passenger volumes are loaded onto the regional highway network in the greater Los Angeles area of Southern California. Economic analyses, modeling, and GIS technologies are integrated into building a GIS-based OD matrix for freight flow. In order to load the freight flows onto the regional highway network, a three-step feedback transportation model is developed. It includes trip generation, trip distribution,and traffic assignment. A doubly-constrained gravity model is used to co-distribute and calibrate personal trips and freight trips in the trip distribution step. A version of User- Optimal-Strict On Network Assignment (UO-S-NA) is used to assign all of the vehicle trips to the regional highway network.