The Changes of Urban Structure and Commuting: An Application to Metropolitan Statistical Areas in the United States

While urban structures have been delineated at the regional level, few works have explored the impact of urban structures on commuting at this same level. This article studies how urban structures affect commuting from 2000 to 2010. It applies a spatial statistical tool, standard deviation ellipses, to capture spatial patterns of jobs and residential workers for metropolitan statistical areas (MSAs). Two urban structure indexes are constructed to illustrate different decentralization levels of employment with reference to the distribution of residential workers; one illustrates the spatial decentralization of high job density nodes, while the other shows the spatial decentralization of moderate job density nodes. Commuting times of two modes by private cars and public transit are analyzed along with the number of commuters. The results highlight three findings: (1) MSAs become more compact in terms of employment distribution, (2) more decentralized high-density nodes lead to less total commuting times, and on the other hand, more decentralized moderate job density nodes contribute to longer commuting times, and (3) the decentralization of high job density nodes is associated with less commuting time of private cars, while they have insignificant effect on commuting time of public transit.