This EnviroAtlas web service includes maps that illustrate factors affecting transit accessibility, and indicators of accessibility. Accessibility measures how easily people can reach destinations such as their workplaces and can be measured in terms of both time and distance. It is affected by factors such as the proximity of housing to jobs, transit stops, stores, and services; the availability of various transit modes; and land use patterns. This dataset was produced by the US EPA to support research and online mapping activities related to EnviroAtlas. EnviroAtlas (https://www.epa.gov/enviroatlas) allows the user to interact with a web-based, easy-to-use, mapping application to view and analyze multiple ecosystem services for the contiguous United States. The dataset is available as downloadable data (https://edg.epa.gov/data/Public/ORD/EnviroAtlas) or as an EnviroAtlas map service. Additional descriptive information about each attribute in this dataset can be found in its associated EnviroAtlas Fact Sheet (https://www.epa.gov/enviroatlas/enviroatlas-fact-sheets).