1) Detailed data: Our method measures the exact distance between every residential unit and food retailer. We did
not rely on the creation of population-weighted centroids (e.g. Sharkey and Horel 2008) and we measured distance
Fig. 4. Food Deserts: Greater than 10 mile mean distance between food retailers and residential units by census tract.
172 J. McEntee, J. Agyeman / Applied Geography 30 (2010) 165–176over the road network; roads are the primary mechanism for which the majority of people in rural areas use to
travel.
2) Time-sensitive: Our primary goal was to contribute towards the development of a food desert identification strategy that
was relatively easy to employ and did not require collection of primary data, which usually entails extensive time and
resources. After examining the locations of census tracts that travel the furthest in conjunction with poverty and educational
attainment, our approach has highlighted areas of the state that are more likely to experience the symptoms of
inadequate food access, such as food insecurity and hunger. Total analysis time was approximately twenty hours (not
including analysis design and review of results). The task of measuring residence to retailer by hand, without the utilization
of GIS, would have been prohibitively burdensome.
3) Applicability: Our method is applicable to other rural locations. All states have publicly available GIS data that details road
networks. Geo-coded store locations are a proprietary item that can be purchased or accessed through a local college’s or
university’s library. The e911 database provided by the Vermont Center for Geographic Information is unique in that it held
statewide data already compiled into GIS-ready format. While few other states have a product that is centrally managed
and as complete, other states often have sub-sectional data available and are moving towards statewide coverage and
availability. Therefore, the analysis provided here establishes a groundwork for similar applications in other rural areas of
the United States as the data becomes available enabling a uniform approach across the country.