Neighborhood Supply Issues

Abstract

Chapter 3 reviewed the literature regarding the influence of the built environment on travel behavior, and chapter 4 then described one way the issue might be usefully studied. The empirical work in chapter 5 provided intriguing results while illuminating some complex issues that remain unresolved in the analysis of urban design and travel behavior. Overall, our analysis thus far suggests that the link between the built environment and travel is intimately tied to the how urban form influences the cost of travel, and that the effect of design is complex in ways not adequately appreciated in most policy discussions. Neighborhood design in particular might affect automobile travel, but we still have much to learn about the nature, generality, and policy role of any such link. That said, our analysis so far has been conventional in that it has focused on travel behavior. Yet that is only half of the story. It is also important to understand whether and how alternative land-use strategies might be more broadly implemented. Having sketched out the role of the demand for travel in understanding the impacts of urban form on trip making, we now examine the supply of urban form. Put another way, how do communities shape cities toward transportation ends? As discussed in chapter 3, a major difficulty in empirical work on travel behavior and urban design is that persons might choose residential locations based in part on how they wish to travel. Those who prefer walking are more likely to choose to live in pedestrian-friendly neighborhoods. People who prefer to commute by rail are more likely to live in transit-oriented developments. If so, then simply looking at differences in travel patterns across different neighborhoods does not give insight into how urban design causes persons to travel differently. It is possible that urban design might not lead persons to travel differently at all, at least not in the sense of changing the way they desire to travel. If there are an adequate number of communities providing less auto-dependent environments, then building more might have no influence on travel behavior.