Commuting and Congestion: A Simulation Model of a Decentralized Metropolitan Area

In this paper, a simulation model of commuting behavior in a metropolitan area with decentralized employment and congestion is developed. The model is used to explore the linkage between the dispersed land use patterns in U.S. cities and long commuting journeys which cause congestion and air pollution. The results show that increasing the number of suburban subcenters in a metropolitan area could reduce commuting by 15% to 50%. However, only about one quarter of total urban travel is for commuting. Therefore the reduction in total urban travel that could be expected to result from even drastic policy measures to decentralize employment would probably be low—perhaps as small as 5%. Data are also presented giving private versus social costs of commuting per mile in central cities and suburbs.