The Public Policy Institute of California has recently released a new policy paper entitled Driving Change: Reducing Vehicle Miles Traveled in California. The paper assesses the prospects for successful implementation of SB375, California's 2008 law that requires regions to achieve transportation-related greenhouse gas emissions reductions from land use planning measures.
A central argument of the paper is that SB375's emphasis on facilitating increases in residential density around transit as a means of reducing VMT may be misplaced. Instead, PPIC argues that it is job densities around transit stops that are most strongly associated with transit use, and hence reductions in VMT. One plausible reason for this relationship may be that it is "relatively easy for workers to drive or bike from home (where their cars or bikes are) to a transit stop or station, but not as easy to drive or bike from a transit station or stop to their workplace" at the destination end of the trip (p6).
If indeed this conclusion is valid (and PPIC cites three recent publications by prominent experts or research bodies supporting it), it has implications that go far beyond even those suggested here by PPIC. Within the planning world, the problem of sprawl has overwhelmingly been framed in terms of residential development patterns, while far less attention is devoted to the location of jobs. Numerous books and papers have examined the origins of residential sprawl in zoning policy, mortgage lending, cultural values and a host of other interlocking social forces. Many fewer have examined the forces driving the dispersion of jobs into suburban locations.
What might be gained by an increased focus on reversing job sprawl? Well, for one thing, it may be an easier task than reversing residential sprawl. Job location decisions are made by far fewer individuals than comprise regional housing markets, and those individuals are at least potentially easier to coordinate. Business leaders are often more civic-minded than many people assume, and there is a rising appreciation in the business world of the value-enhancing characteristics of dense urban professional networks.
Re-densifying jobs may also ameliorate the more subjective argument that sprawl fosters social fragmentation and alienation. In older American cities, people used to work (and shop) downtown. Arguably, much of the sense of publicness people apparently experienced in those times derived from people's repeated journeys to work and retail through bustling and diverse city streets. Even in small towns and older suburbs, despite low-density housing, there was a physical center dominated by shopping and workplaces that nearly everyone in the community visited routinely, often multiple times per week. Indeed, one could argue that, with the exception of industrial-era immigrant neighborhoods, Americans have never lived at dramatically greater density than they do now -- but often did work and shop in very much more public settings than they do today.
Higher-density urban living is growing in popularity in America because the nation is changing demographically to include more single young professionals, childless couples, and two-career families that prosper best in large job markets. Planners should continue to seek ways to provide these people the housing products they need and want -- but also should give more serious and sustained thought to where they and their compatriots work each day, and how they travel there.