We also evaluated the degree to which the California populations who experience the highest overall exposure to PM2.5 from on-road vehicles are disproportionately comprised of people of color, and how this pattern has evolved over time. To do so, we binned the California population by decile of modeled exposure to PM2.5, and then compared the racial-ethnic composition of each decile in 2000 and 2019 (Fig. , midpoint result in Fig. ). From 2000 to 2019, Hispanic Californians are overrepresented at the highest exposure deciles. While the California state population is 37.6% Hispanic, the highest decile of exposure for emissions in ) . We model the disparities and additive contributions of each vehicle fleet type at the state-level for the most exposed racialethnic group, Hispanic Californians, to identify which vehicle types have an especially influential role on their exposures and disparities.