Abstract :
Recent US traffic growth is summarized and its causes discussed, emphasizing the complex causal linkages between automobile travel and the underlying land use patterns that shape it. This causal framework is used to frame a discussion of how the demands for vehicle travel might be reduced through suitable land use impacting policy instruments. This includes instruments that alter the location, mix and intensity of traffic generating and attracting land use, as well as instruments that affect land development through the supply of added transportation capacity. The existing scientific evidence for the effects of land development patterns on aggregate vehicle miles of travel is found to be of limited use at the present time. For the most part this results from past data limitations and because of the variety of both spatial and temporal scales across which such data needs to be collected and analyzed. It is also concluded that successful travel reduction policies are likely to evolve as part of a broader public policy debate over quality of life issues, notably those involving “urban sprawl” and the balance of economic development against environmental sustainability. The full costs of expanding while also maintaining the current automobile dominated transportation infrastructure may also provide an economic rationale for change.
