Urban Development with Sustainable Public Transit Services

It is known that urban density is positively correlated with transit service usage. Previous studies, however, analyzed the problem descriptively based on statistical approaches. This study seeks to derive prescriptive results of the relationship between urban density and rail service sustainability. As a start, this study considers an idealized metropolitan region with a uniform urban development density and a central business district (CBD) at its center. Trips generated from the region to the CBD are either served by the rail service or private cars, as described by a discrete choice modal split model. We study the sensitivity of urban development density on the financial sustainability of the rail service by examining the supply and demand patterns. Through the analysis, the result sheds light on the threshold urban density required, below which the service cannot be sustained without subsidy.