Using Land Use Policy to Address Congestion: The Importance of Destination in Determining Transit Share
Given the costs and political difficulties inherent in urban highway expansion, one of the few options available for policy makers hoping to reduce congestion is to increase the use of non-auto travel modes, especially transit. However, it is difficult to substantially impact transit use at a large scale because it is strongly dependent on development density and other slow-changing features of urban land use.
This paper argues that policy makers hoping to reduce congestion through increased transit use should focus on increasing the size of downtowns, and on developing downtown-like centers in suburban locations. There are both empirical and practical arguments. Empirically, large, dense destinations have a very substantial impact on mode choice, regardless of the characteristics of the trip origin. Much of the apparent impact of residential density on mode choice is actually due to the fact that residents of high-density areas are more likely to work in a downtown.
There are two practical arguments for focusing on downtown-style development rather than increasing residential densities. First, it will probably be easier to increase densities in commercial areas, both because political opposition is less acute, and because developable land is often more available. Second, commercial areas can be developed at densities an order of magnitude higher than residential neighborhoods, with a corresponding impact on transit ridership.