A key purpose of the transportation system is to provide access to critical services such as grocery stores. Maintaining food access during an emergency or other disruption is all the more important, particularly for vulnerable households. Most people in the United States rely on the use of private automobiles for grocery shopping. Thus, disruptions to road networks due to heavy precipitation, flooding, or even major maintenance and repair projects present notable threats to accessibility. Regional planning models that address food accessibility issues (not all do) typically do not consider households’ familiarity with grocery locations. However, during a disruptive event, a household’s familiarity with at least one available route to a retail grocery location becomes paramount. Identifying the roadways that are most critical to food access can help decision makers devise strategies to mitigate the risks of food insecurity for vulnerable households and populations.
Researchers at the University of Vermont developed a methodology that provides an ordinal measure of demand-side food access. It takes into account the spatial distribution of both the origin and destination, the topology of the road network, and the characteristics of the roadway network such as capacities, volumes, and travel speeds. The analysis considers household familiarity with retail grocery locations, destination weighting to account for retail grocery characteristics (square footage), and origin weighting to account for household vulnerability. The researchers demonstrated the methodology using the travel demand model for Chittenden County, Vermont. This policy brief summarizes the findings from that research and provide policy implications.