Urban form, air pollution, and walking behavior: A study of Salt Lake County, Utah

Abstract

IntroductionWalkability is an essential concern in urban and public policy, as it is highly related to public health, social equity, and climate change. This paper examines the impacts of urban space and air pollution on walking behaviors across census block groups in Salt Lake County (SLCo), Utah, including walking trip origins, destinations, and paths. MethodsLocal Moran's I index is applied to capture the spatial clustering of walking behaviors. Non-spatial and spatial generalized linear models based on the quasi-Poisson function were then comparatively constructed to explore the relationships between urban form, air pollution, and walking behavior, using walking time and frequency as dependent variables. ResultsWe found that downtown Salt Lake City was the main place for walking activities, and more walking activities occurred in eastern SLCo than in the western part, while the western part has a higher concentration of minority populations. Compact development may promote local walking behavior, but types of mixed land use matter: while job mixture was a catalyst for walking, job-housing mixture was not. Concerning the role of air pollution, particulate matter and volatile organic compounds significantly reduced the length of walks. However, taking frequent short walks might further expose people to pollutants such as ammonia and sulfur oxides in urban centers. ConclusionsThis study explored the intra-urban relationships between urban form, air pollution, and walkability. Air pollution is a critical concern for walkability. Promoting compact development alone is insufficient; efforts should also be made to improve job mixture, reduce air pollution, and, more broadly, promote polycentric development.