Abstract: Four data products developed by the EPA to consistently measure the built environment and transit accessibility of neighborhoods across metropolitan regions and across the United States. Each product summarizes the characteristics of census block groups. Users can download data, browse the data in interactive maps, or access the data through web services. The data products are: 1) The Smart Location Database summarizes more than 90 different indicators associated with the built environment and location efficiency. Indicators include density of development, diversity of land use, street network design, and accessibility to destinations as well as various demographic and employment statistics. Most attributes are available for all U.S. block groups. EPA first released a beta version of the Smart Location Database in 2011. The initial full version was released in 2013, and the database was updated to its current version in 2021; 2) The Access to Jobs and Workers Via Transit Tool provides indicators of accessibility to destinations by public transit. Indicators summarize jobs accessible by transit as well as workers, households, and population that can access the block group via transit. Coverage is limited to metropolitan regions served by transit agencies that share their service data in a standard format called GTFS; 3) The National Walkability Index provides walkability scores based on a simple formula that ranks selected indicators from the Smart Location Database that have been demonstrated to affect the propensity of walk trips. Currently, the National Walkability Index dataset ranks each block group relative to all other block groups in the United States, but individuals can use downloadable data and the "how-to" document to construct an index for a smaller universe of block groups, like a state, metropolitan area, or city; 4) The Smart Location Calculator is a dataset and interactive tool that measures the location efficiency of workplace locations. Developed by EPA and the General Services Administration (GSA), the interactive map allows users to explore the data, download the dataset, and access the accompanying documentation. The Smart Location Calculator is a simple tool for exploring how workplace location affects worker commute travel. The tool provides location efficiency scores for a user-entered address, as well as location efficiency data summarized at the block group level. All of the scores are relative to the region. Other indicators include worker commute greenhouse gas emissions, mode share, vehicle miles traveled, and workplace accessibility via transit. Only the Smart Location Index scores and related variables from the 2021 Smart Location Database version are available at this time.