JAPA Article Finds Compact Development Does not Reduce VMT


JAPA Article Finds Compact Development Does not Reduce VMT

A recent article in the Journal of the American Planning Association (JAPA) finds unlike earlier studies, compact development does not encourage people to drive less. This surprising result is newsworthy for two reasons: First, it goes against a consistent narrative that compact development is almost always better. Second, it shows that JAPA is willing to print controversial articles that upset some prominent planners, something that it has been hesitant to do in the past.

The article by Mark Stevens examines the 5D factors included in the landmark analyses of the built environment on travel behavior written by Reid Ewing and Robert Cervero: density of population, diversity of land uses, design of the street network, destination accessibility and distance to transit. Stevens add two new variables. The first is self-selection bias in which people who choose to drive less move to neighborhoods in which they can take alternative modes. The second is publication bias in which articles, which fail to support the prevailing view do not get published.

After adding these factors, Stevens finds that most features of the built environment have little to no impact on auto use. Most significantly, he suggests that it is not cost effective for these cities to adopt these policies because their costs are very high and their benefits limited.

To be fair, the initial assessment from Ewing and Cervero argued that most elements of the built environment had only a modest impact on travel behavior. Yet that did not stop folks who promoted a smart agenda from wildly exaggerating the results of the study to serve their interests.

More important than the article is the fact that JAPA published it. Much of the credit for doing so should go to Editor Sandra Rosenbloom and APA Executive Director James Drinan. In a Letter from the Editor, Rosenbloom states that she believes there is publication bias not to publish articles that, “…(C)all into question a central belief of current planning thought.” She goes on to argue that the belief that JAPA has no interest in publishing contrarian articles is not true. She argues doing so would be scholarly malpractice. However, she does believe that in the past some JAPA reviewers were unwilling to see the validity of studies that they reviewed.

One of the reasons why skeptics believe JAPA may not have an interest in publishing contrarian articles goes back to 2004. Bent Flyvbjerg and his colleagues had studied 258 infrastructure projects to determine the amount of cost-overrun. He found an average cost overrun of 28%. And worse, Flyvbjerg found no improvement in cost forecasting over the past 70 years. This suggested to the authors a lack of solutions, a lack of interest in finding solutions and a deliberate attempt to underprice certain types of projects so that they would be politically acceptable to build.

Despite getting excellent reviews from JAPA’s editors, APA bosses were not fans of the article. They worried that it would undercut support for transportation in general and planning in particular. Simply put, APA management felt that JAPA, despite being the oldest, most respected journal of the Planning profession, should not publish or promote articles that were critical of planning.

It is refreshing to see strong principled leadership not only from JAPA’s Editor but also from its Executive Director. Having management pressure JAPA editors to cease publication of an unflattering article was one of APA’s darkest days. I congratulate current leadership for publishing articles critical of the status quo because planners should read and consider all peer-reviewed properly supported research, especially those articles with which they do not agree.