Urban system equilibrium analysis in a polycentric city and rail transit investment estimation

Based on a continuous multinomial logit model, this paper develops a stochastic urban system equilibrium to investigate residents' choices of residential location and work place in a linear polycentric city, which takes into account individual taste heterogeneity in terms of location choice. In the urban system, people commute by private car, bus or rail transit between their home and working places. The model is then used to explore the impacts of urban rail transit investment on residential distribution, housing price, and attractiveness of CBDs for employees through comparison of the urban system equilibrium performances before and after the introduction of rail transit. The result reveals that the introduction of urban rail transit makes employment more concentrated in the relatively developed CBD and further widens the gap of attractiveness between the two CBDs. It also finds that improvements of traffic conditions encourage residents to migrate towards the suburbs, and thus leads to a more uniform distribution of residential density and housing price across the city, weakening the advantages of central areas.