by Chang-Hee Christine Bae
This paper evaluates the relative importance of land use changes versus technological solutions to reducing transport-related air pollution. It suggests that land use approaches have very little prospects of reducing emissions compared to technology. The ZEV (zero emissions vehicle) mandate was the wrong route to take, primarily because of the failure to solve the battery (hence the range) problem. However, it may have stimulated the automobile companies to focus their R & D more on alternative fuel vehicles. As a result, there are two hybrid (gasoline-electric) vehicles on the U.S. market in the year 2000, the Honda Insight and the Toyota Prius, with more to follow. In addition, SULEVS, such as the special versions of the Honda Accord and the Nissan Sentra-CA, are equally promising. These vehicles solve the range problem, and the power problem is getting close to solution. A key argument is that it may be easier to change vehicle preferences than residential location and dwelling type preferences, but incentives (e.g. emission fees on the popular SUVs) and other policy interventions may be needed.
Planners have a natural tendency to believe that they can alleviate a wide range of economic and social problems via planning interventions, especially by land use policies. This belief is what attracted most of them into the planning field in the first place. A good example is the current debate about "smart growth," promoted as a means of simultaneously addressing the problems of the inner cities, spatial injustice and the evils of suburban sprawl. In this paper, I focus on a much narrower, if not totally unrelated problem: the potential for changes in land use (and associated changes in travel behavior) to reduce automobile-related air pollution. I compare this policy with alternative approaches, such as improvements in emissions technology and the development of alternative fuel vehicles. It is tempting in such an analysis to adopt a balanced, safe position: we need all the strategies available. I wish to argue that for this particular problem, this is not the case. On the one hand, land use options will not work: the settlement pattern can only be changed at the margin; in any event, land use changes take a very long time to implement; and, even if implemented, they would have negligible effects on vehicle miles traveled (VMT). On the other hand, we do not have to be confirmed "technological optimists" to believe that we are on the verge of major technological advances, now completely predictable, that will dramatically reduce automobile-related emissions. Because the land use prescriptions (especially in view of the vast but still growing literature on sprawl) are very familiar even to laypersons, I will give more attention to the technological issues (but from the perspective of a transportation/environmental planner rather than that of an automotive technology engineer).