PM2.5 mass concentration fields associated with on-road motor vehicles were created with 1-km spatial resolution for four heavily polluted urban areas in California: Los Angeles, San Francisco, Sacramento, and Fresno. Monthly-average concentration fields were created for the years 2000 through 2011. Concentration fields were predicted with a Chemical Transport Model (CTM) based on meteorology fields predicted by the Weather Research and Forecast (WRF) model and emissions fields predicted based on measured activity combined with emissions measurements and spatial surrogates. Statistical bias correction was applied to bring predicted PM2.5 concentrations into close agreement with measured values. Averaged across all years, motor vehicle tailpipe emissions generally accounted for less than 5% of the total PM2.5 concentrations. PM2.5 mass concentrations across the study regions decreased by 10-20% between the years 2000-2011, with similar declines predicted for motor vehicle tailpipe contributions to PM2.5. The BenMAP-CEv1.5 model created by US EPA estimates that reductions in PM2.5 emitted from motor vehicles between 2000-2011 avoids 300 deaths each year with an equivalent monetary value estimated at $2.3B yr-1. Future studies may use the air pollution exposure fields developed in the current project to analyze health disparities across different population segments or to search for epidemiological associations between pollutant concentrations and health effects.