A Mobility Equity Index for Evaluating Transportation Options to Access Healthy Food Outlet Points in Austin, TX, USA
Abstract
Background: Mobility is a fundamental determinant of when and how people access resources, such as medical care, economic opportunity, outdoor recreation and nutritious food. Urban infrastructure should support multiple mobility options to encourage active transport, improve individual and community health, and reduce congestion in growing urban cities. In this study, we use a mobility equity index to assess the balance of mobility options (biking, walking, public transit, and driving) at the neighborhood level and in areas surrounding healthy food retail. The resulting mobility equity values were then tested against sociodemographic and structural characteristics of neighborhoods, such as urbanicity, vehicle availability, and income, to assess for association between mobility equity and neighborhood factors. Methods: ArcGIS was used to aggregate data from the City of Austin Open Data Portal and the 2015 U.S. Census, American Community Survey 5-Year Estimates, at the Census Block Group (neighborhood) level. In SAS, four constructs of mobility—walkability, bikability, drivability, and public transit accessibility—were calculated for each neighborhood, normalized, and then converted to a relative range (0 – 1). The scaled constructs were used to calculate a mobility equity index for each neighborhood. Logistic regression was used to model the association between high mobility equity and vehicle availability, household income, urbanicity, and racial/ethnic characteristics of neighborhoods. Odds ratios and 95% confidence intervals were used to interpret significant associations. Finally, the new mobility equity index was used in a case study to examine transportation options surrounding healthy food retail. 3-mile network buffers were created in ArcGIS around the healthy food retail point locations. Descriptive statistics were generated for the healthy food buffer areas to evaluate differences in accessibility of stores based on income, majority race/ethnicity, vehicle availability, and urbanicity of the area surrounding the store. Results: Significant associations were found between high mobility equity index values and the odds of living in a neighborhood that is low-income, has high vehicle availability, and is majority Hispanic (respectively). No association was found between urbanicity and mobility equity. Healthy food stores in the downtown/central Austin tended to have the highest mobility equity values, as compared to those in North Central Austin or far south. Additionally, stores with higher mobility equity tended to be in areas that are majority mixed race/ethnicity, low income, and have high vehicle availability. Conclusion: The development and demonstration of a mobility equity index is an innovative approach to addressing pressing infrastructure concerns as urban cores continue to grow in population. We can conclude the relationship between mobility and sociodemographic factors is complex, though mobility equity may be higher amongst low-income populations due to societal norms that suggest alternative transportation is for the lower class. Future studies should validate this mobility equity index; consider additional data to utilize in mobility constructs; and, conduct a study across multiple cities in order to compare mobility across multiple urban environments.
Subject Area
Public health|Public policy|Transportation
Recommended Citation
Moncure, Patricia A, "A Mobility Equity Index for Evaluating Transportation Options to Access Healthy Food Outlet Points in Austin, TX, USA" (2017). Texas Medical Center Dissertations (via ProQuest). AAI10683782.
https://digitalcommons.library.tmc.edu/dissertations/AAI10683782