In accordance with State law, CARB and other State agencies are working to improve access to clean transportation options for all Californians. Existing tools identify "disadvantaged" California communities according to a variety of environmental and socioeconomic factors and, importantly, highlight potential health impacts associated with these factors. However, these tools do not currently characterize disparities in access to clean transportation options (including active modes such as walking and cycling), access to jobs and other key destinations, transportation cost and time burdens, etc. This research will identify indicators for transportation access disparities along with a screening method and visualization tool that will be useful for analyzing data related to this and other important social determinants of health. The project is an integral part of CARB's implementation of Assembly Bill (AB) 32, Senate Bill (SB) 375, SB 350, and SB 150. Additionally, it contributes to California's commitment to ensure that all segments of society benefit from the State's climate change agenda, including disadvantaged populations and neighborhoods (all four of the cited legislation plus SB 535, AB 1550 and AB 617).