Last week, I wrote a post detailing how much car crashes cost. An alert reader asked some followup questions about how to reduce his risk:
Does a decrease in vehicle-miles translate to a decrease in injuries? Am I relatively safer on my bike? On the bus?
Here are some quick answers. First: the more you drive, the greater your chance of getting in a crash. See, for example, this chart from a Victoria Transport Policy Institute analysis of car crashes in British Columbia:
The relationship is pretty close to linear. So if you want to decrease your crash risk, the most obvious strategy is to arrange your life so you can drive less, if you can. Of course, some roads are riskier than others—and rural two-lane highways are among the riskiest. Congested urban roads and streets tend to have more crashes per mile driven than average, but fewer fatalities—slower speeds make crashes less deadly. Which may be one reason why the risk of dying in a car crash is higher at the urban fringe than in center cities or inner-ring suburbs, and why sprawling cities are more dangerous than compact ones.
Next: If you want to be safer, take transit. Measured per passenger-mile, transit buses and commuter rail are about as safe as you can hope for; buses seem to be more than 10 times safer than cars for their occupants, while commuter rail is about 80 times safer. (But both are more dangerous than cars for other occupants of the roads.) I wish I could say that biking would make you safer, but it doesn’t seem to; mile for mile, biking is about 10 times deadlier than driving. Exercise benefits may partially offset the increased crash risk.
It’s a shame that biking is so risky in the US. Biking fatalities are down, of course—they fell by 27% between 1975 and 2001—but mostly because of a steep drop in cycling by children. But in Germany, the exact opposite has happened: the number of bike trips doubled between 1975 and 2000, while the number of bike fatalities dropped by 64%. The difference, according to some researchers, is that public policy in Germany has emphasized bike and pedestrian safety—including infrastructure, traffic calming, traffic education, and traffic regulations—while policies in the US tend to emphasize fast travel by car.
One side note—although traffic fatality rates in the US are among the highest in the developed world, US drivers aren’t particularly unsafe, nor are the roads we drive on. Measured per mile, our fatality risk is about average. The real difference is that we drive much more than our counterparts in other nations—and all else being equal, more driving means more car crashes.