Access Across America: Methodology 2024

Accessibility is the ease of reaching valued destinations. It can be measured for a wide array of transportation modes, to different types of destinations, and at different times of day. There are a variety of ways to define accessibility, but the number of destinations reachable within a given travel time is the most comprehensible and transparent as well as the most directly comparable across cities.

This report describes the methodology used to calculate and aggregate accessibility by mode in the report series Access Across America 2024. For each of the auto, bicycle, transit, and walk modes, this report describes the input data, necessary software, data handling approach, and calculation details for assigning cumulative job accessibility using each of the 8.2 million U.S. census blocks as origins. Additionally, the report describes how these data are weighted by the density of residents to create reportable average accessibility statistics.

Results for 2024 calculations are presented in the Access Across America report series.