Study Finds Strong Evidence that Parking Causes Driving

Eric Jaffe reports on the latest evidence that excessive parking actually causes more driving. The study, by Chris McCahill of the State Smart Transportation Initiative along with three University of Connecticut scholars, offers "compelling evidence that parking provision is a cause of citywide automobile use." According to Jaffe, the study found that evidence by "taking a page from epidemiology—adopting a framework meant for 'inferring causality' in the face of a statistical association known as the Bradford Hill criteria."

Jaffe's coverage of the study includes a close look at the methodology and findings of the study, but even for lay people it's important to note how difficult it is to prove causality (Jaffe takes the example of the link between cigarettes and lung cancer as an example)—especially with regard to a subject as political fraught and contentious as parking. In the case of this study, however, the deliberateness required to prove causality elucidates very clear insights into the consequences of parking policy around the country.