We have demonstrated that while modeled PWM PM2.5 exposures and absolute exposuredisparities attributable to on-road mobile sources have decreased over the past two decades across all population groups, relative disparities have remained at both the average and at the extreme ends of the exposure distribution for Californians of color and residents of overburdened communities. Emissions from LDVs and HDVs impact disparities in different ways. LDVs contribute the most to PM2.5 concentrations and absolute disparity, while emissions from HDVs most disproportionately expose people of color relative to other fleet types, thereby highlighting the importance of mitigating emissions from both vehicle types. Of the groups considered here, residents of AB617 communities in aggregate experience the highest levels of PM2.5 exposure from on-road vehicles, although PWM exposures for these residents has declined by over 60% since 2000. There is substantial heterogeneity among AB617 communities in terms of the total exposure concentration and the relative contribution from each vehicle type.