On average, the Los Angeles area and its AB617 overburdened communities have high PWM exposures and high contributions from LDVs (> 60%). In the Central Valley, while the PWM exposures are lower, the contributions from HDVs are substantially higher (e.g., ~60% in Arvin/Lamont). The diversity in fleet contributions to individual communities showcases the importance of community-specific emissions reduction planning. While a community with a high share of LDVs, for example, might benefit more from policy actions that directly reduce those emissions (e.g., more electric bus routes, street conversion to bicycle paths), different strategies may be more appropriate for a community dominated by HDVs (e.g., additional diesel fuel emissions limits, truck electrification, low emission zones). These differences likely arise from differences in spatial distributions of sources relative to residences and the magnitude and mixtures of vehicle activity that occur at the community scale. In sum, our results support the approach of enabling communities to identify and mitigate the largest contributors to local exposures and disparities.