The Minimum Circuity Frontier and the Journey to Work

People travel between places of residence and work destinations via transportation networks. The relation between selection of home and work locations has been heavily debated in the transportation planning literature. In this paper we use circuity, the ratio of network to Euclidean distance, to better understand the choice of residential location relative to work. This is done using two methods of defining origins and destinations in twenty metropolitan regions in the United States, with more detailed analysis of Minneapolis-St. Paul, Minnesota and Portland, Oregon. The first method of selection is based on actual choice of residence and work locations. The second is based on a randomly selected dataset of origins and destinations in the same regions, followed by a comparison between the two methods for these regions. The study shows circuity measured through randomly selected origins and destinations differs from circuity measured from actual origins and destinations. Workers tend to reside in areas such that the journey to work circuity is lower than random, applying intelligence to their location decisions. Consistent with traditional urban economic theory, this suggests locators wish to locate on the frontier with the largest residential lot at the shortest commute time, but in contrast with the classic model which simplifies transportation networks to be uniform, we cannot assume that all possible home-work pairs are on the frontier. This finding, developed from microscopic data not previously used for this question, reveals an important issue related to residence choice and location theory and how resident workers tend to locate with respect to network configuration in an urban context