Half-Mile Circle

Abstract

The 0.5-mile distance has become accepted for gauging a transit station's catchment area in the United States and is the de facto standard for the planning of U.S. transit-oriented developments (TODs). Planners and researchers use transit catchment areas not only to make predictions about transit ridership and transit impacts (socioeconomic and on land use) but also to prescribe regulations (e.g., relaxing restrictive zoning or carving out TODs for financial plans). This radius is loosely based on the distance that people are willing to walk to transit, but the same reasoning has been used to justify other transit catchment areas. Station-level variables from 1,449 high-capacity American transit stations in 21 cities are used to determine whether a clear benchmark between distance and ridership provides a norm for station-area planning and prediction. Results indicate that, for the purposes of predicting station-level transit ridership, different catchment areas have little influence on a model's predictive power. This finding suggests that transit agencies should use the easiest, most readily available data when estimating direct demand models. The evidence is less clear for prescribing land use policy. Nevertheless, results support the use of a 0.25-mile catchment area around transit for jobs and a 0.5-mile catchment area for population. Even though these distances probably will vary, depending on the location and the study purpose, the distances are good starting points for considering transit-oriented land use policy or collecting labor-intensive data, such as surveys, about transit-adjacent firms or households.