Commentary: Counting Road Deaths by VMT Minimizes the Harm and Normalizes Traffic Violence

Writing in Bloomberg CityLab, David Zipper argues that the United States is using the wrong method to count traffic deaths. 

Unlike most other countries, the United States reports traffic deaths as compared to vehicle miles traveled (VMT). But when you look at deaths per capita, the United States has more than twice as many road fatalities as peer countries. 

“In the US, many transportation professionals favor this deaths-per-distance metric, because it supposedly accounts for uniquely American factors like the country’s physical enormity, the scale of national infrastructure and residents’ “love affair” with the automobile,” Zipper explains. But this analysis obscures the real costs of traffic violence and normalizes crash fatalities. 

According to Zipper,

Worse than misleading, normalizing crash fatalities by distance driven avoids acknowledging essential reasons why people in the US are killed on the road with such startling frequency — and it precludes opportunities to change course.

Zipper explains that individual choices such as taking transit or choosing a job closer to home can reduce the amount of miles driven and, therefore, the likelihood of getting in a crash. “But viewed through the myopic lens of deaths per mile, neither change would seem to affect safety, since the risk of crashing during a given mile of driving is unaffected.” 

The car-centric design of most U.S. communities is a major reason for the massive number of traffic deaths each year — but there are opportunities to make a difference by changing single-use zoning, eliminating free parking, and supporting public transit, for example. “These are not immutable conditions; they are the direct result of policy choices that are inducing Americans to drive more — and to crash more, too.”