Freight movement is essential to our prosperity, but it also generates large external costs in the form of additional congestion, air pollution, and truck-related accidents that further compound congestion and air pollution. Unfortunately, these external costs are not yet fully understood. The idea of shifting freight delivery off-peak was proposed a long time ago but it is still controversial. The purpose of this project is to better assess some of the social benefits of shifting freight operations off peak with an emphasis on congestion, air pollution (CO2, NOx, and PM), its health impacts, and accidents related to freight trucks, using an innovative approach and state-of-the-art tools. Our focus will be on the San Pedro Bay Ports (SPBP) of Los Angeles and Long Beach in Southern California, which is one of the largest container port complexes in the world; it contributes significantly to both California’s and the nation’s economies but its growth is threatened by its environmental performance. We will build on our previous UCTC research in order to provide new insights into the impacts of off-peak SPBP freight corridor operations.