Research points to factors affecting crash rates among states

By Chris McCahill

The transportation industry is constantly working to improve safety on America’s roads—often through in-vehicle improvements, infrastructure design, new technologies, education, and enforcement. But without looking at safety trends and factors more broadly, we risk missing important opportunities to make the most substantial gains.

A new report from the University of Michigan Transportation Research Institute highlights differences in fatal crash rates among the 50 states and D.C. The safest are D.C. and Massachusetts, which have fewer than five deaths per 100,000 people, compared to the national average of 10.4 and the highest crash rate of 22.6 in Montana. These numbers can tell us a lot about what factors contribute to upwards of 30,000 to 40,000 preventable deaths each year.

The report’s authors note that fatality rates are highest in states with extensive rural road networks and that differences in alcohol consumption, age distribution, driver aggression, and climate seem to play some role. “Speed is likely to be among the most important causative factors,” says the report’s lead author, Michael Sivak, who also compared maximum posted speed limits among the states.

In a separate analysis of the data, Richard Florida reveals that car deaths are less common in denser, more urban states and in those with strong, knowledge-based economies, which leaves other states at a particular disadvantage. It also suggests, however, that urban policy could be important to consider in preventing transportation-related deaths. Similarly, Florida points to evidence that fatality rates are highly correlated with VMT, which supports the notion that increased driving might be the key factor explaining this year’s surge in traffic deaths and that VMT reduction could make our roads considerably safer.

Chris McCahill is a Senior Associate at SSTI.