Overview
The Food Access Research Atlas (FARA) includes two measures of retail food access, the Supplemental Nutrition Assistance Program (SNAP) authorized Retailer Access Map (SRAM) and the Large Retailer Access Map (LRAM). Together, these mapping tools present indicators of food access for low-income and other census tracts using different measures of food retailer accessibility.
These measures can help highlight neighborhoods where distance and transportation barriers may limit access to food retailers. Limited access can influence which stores people can reach, the time and cost required to travel, and how often households are able to shop.
What can you do with the Atlas?
- Create and compare maps showing food access indicators by census tract using two mapping applications, each offering different measures of food retailer accessibility:
- SNAP-authorized Retailer Access Map (SRAM)
- Large Retailer Access Map (LRAM);
- Compare food access measures based on straight-line (Euclidean) and driving (road network) distance;
- View indicators of food access for selected populations; and
- Download census-tract-level data on food access measures.
Objectives
Limited access to food sources may make it harder for some people to eat a healthy diet. There are many ways to measure food store access for individuals and neighborhoods. Most measures and definitions consider at least some of the following factors:
- Geographic proximity to a store or the number of stores in a given area;
- Individual-level resources, such as family income or vehicle availability; and
- Neighborhood-level resources, such as the neighborhood’s average income and the availability of public transportation.
In the Food Access Research Atlas, low‑income census tracts are defined based on their poverty rates or median family income, and low access refers to being far from a SNAP‑authorized retailer or a large food retailer (supermarkets, supercenters, and large grocery stores).
FARA provides two mapping applications to describe food access along these dimensions, each designed to capture different indicators of geographic access to food, drawing on multiple data sources and methodologies: SNAP‑authorized stores (which include a wide range of retailer formats such as specialty food stores, combination grocery/other stores, convenience stores, small and medium groceries, large groceries, supermarkets, and super stores) and large grocers (supercenters, supermarkets, and large grocery stores).
- SNAP‑authorized Retailer Access Map (SRAM)
- Focuses on access to stores authorized to accept SNAP benefits (SNAP-authorized retailers), except farmers markets and delivery route store types
- A new approach to calculate distance to stores using a straight-line (Euclidean)
- Added measure of distance based on driving (road network)
- Added population of focus: Veterans of the U.S. Armed Forces residing in the tract and their proximity to food stores
- Initially released in July 2026
- Updated as needed, subject to data availability
- Focuses on access to stores authorized to accept SNAP benefits (SNAP-authorized retailers), except farmers markets and delivery route store types
- Large Retailer Access Map (LRAM)
- Focuses on access to supermarkets, supercenters, and large grocery stores
- Last updated in 2021 and renamed from “Food Access Research Atlas” in July 2026 with the addition of the SRAM
- Next update expected Fall 2026
- Updated every 4–5 years, subject to data availability
Information about data sources and definitions for the mapping applications is available in the Documentation section, including the SRAM and LRAM Reference Guides, as well as on the Download the Data pages.