Processed and Derived Dataset for National Food-Access Indicator Sensitivity to Straight-Line and Road-Network Distance in the 2025 USDA SRAM
Description
This repository contains the processed and derived data supporting the study, “Measurement sensitivity of a national food-access indicator to road-network distance: Evidence from the 2025 USDA SNAP-authorized Retailer Access Map.” The dataset was created from publicly available 2025 U.S. Department of Agriculture Economic Research Service SNAP-authorized Retailer Access Map (SRAM) data. The study evaluates how the choice between straight-line and road-network distance affects national food-access indicators while holding the retailer universe, census-tract geography, population data, and indicator definitions constant. The processed dataset covers 84,119 U.S. census tracts across the 50 states and the District of Columbia and includes variables used to evaluate paired straight-line and road-network accessibility measures. Derived outputs support analyses of low-access reclassification, population burden, threshold sensitivity, urban-rural heterogeneity, socioeconomic and demographic patterns, and spatial dependence. The repository includes processed tract-level analytical data, a data dictionary, manuscript-supporting tables, and derived results used in the study. Key derived measures include the Network Accessibility Penalty (NAP), defined as the road-network minus straight-line low-access population share, together with reclassification and population-based accessibility summaries. The primary 1-mile urban/10-mile rural comparison showed that 16.09% of census tracts changed low-access classification, while the estimated population beyond the corresponding access threshold increased by 33.87 million residents under road-network measurement. This repository contains processed and derived research data only. The original source data remain publicly available from USDA Economic Research Service through the Food Access Research Atlas and the 2025 SNAP-authorized Retailer Access Map. Users should consult the original USDA documentation for authoritative definitions, source methodology, and raw data.