Tribby, C.P., Miller, H.J., Brown, B.B., Werner, C.M., & Smith, K.R. (2015). Assessing built environment walkability using activity-space summary measures. Journal Of Transport and Land Use. [Article in Press scheduled for vol. 9 (2016) issue 1 pp. 1–21] doi: http://dx.doi.org/10.5198/jtlu.2015.625
There is increasing emphasis in fields such as transportation planning and public health on walking as a sustainable form of mobility and a means of achieving recommended physical activity for better health outcomes. A key question is measuring the influence of the built environment on walking to determine environmental modifications that enhance walkability. However, it is unclear how to aggregate georeferenced walkability measures to geographic units that are meaningful for behavioral analysis. This paper develops methods for assessing walkability within individual activity spaces: the geographic region accessible to an individual during a given walking trip. Based on objective walkability measures of the street blocks, we use three summary measures for walkability within activity spaces: i) the average walkability score across block segments, ii) the standard deviation, and iii) the network autocorrelation. We assess the method using data from an empirical study of built environment walkability and walking behavior in Salt Lake City, Utah. We visualize these activity-space summary measures to compare walkability among individuals’ trips within their neighborhoods. We also compare summary measures for activity spaces versus Census block groups.