We find that there is substantial spatial heterogeneity in how different vehicle fleet types contribute to PM2.5 exposures. We compare modeled contributions by vehicle type at four spatial scales (Fig. ): (A) statewide, (B) regional, (C) within overburdened communities, and (D) community-scale. Whereas the previous section and Fig. evaluate aggregate exposure and disparity across all AB617 overburdened communities, in Fig. we compare contributions to exposure and disparity within individual overburdened communities. The primary goal of this analysis is to highlight the heterogeneity among diverse communities in how vehicle fleets contribute to PM2.5; our estimates are not meant to precisely capture community-scale pollution concentrations. As with any emissions inventory, modeled concentrations are much more precise with locally-validated, site-specific information that has been observationally verified . To complement our high-level approach to understanding the heterogeneity in source contributions, future community-specific analyses could employ higher spatial resolution modeling tools and local emissions data to better represent the lived experience of individual communities.