Will Bicycling to Work Get You Killed?

Bicycle commuting is on the rise, as evidenced by the following articles in Treehugger.com, the Boston Herald, and USA Today. But if the idea of hitting the road on two wheels — with little to protect you from cars and trucks but good manners — strikes you as pretty risky, you aren’t so far from the mark.

Per kilometer, cyclists are 12 times more likely than car drivers to suffer a fatal accident, according to Rutgers University urban planner John Pucher and Lewis Dijkstra of the European Commission (the same study found traveling by foot to be 23 times more dangerous than driving, per kilometer). To put this finding in perspective, there were 785 bicycling fatalities on American roadways in 2005, compared to 4,881 pedestrian and 43,443 automotive fatalities that same year.

On the other hand, a Danish study found that people who do not bike to work suffer a 39 percent higher mortality rate than those who do. So, assuming you can avoid a fatal accident on the road, biking to work may actually help you live longer.

The risks associated with cycling decrease dramatically when more cyclists are on the road, and especially when those cyclists obey traffic laws. This second point is hammered home in this bizarre but brilliant 1963 bike safety film, “One Got Fat” (the eagle — or is it monkey? — eyed among you will have recognized a clip from this film in the Freakonomics video “Does Sport Cause Crime“).

One thing “One Got Fat” doesn’t mention is helmet use — helmets weren’t widely used until the 1970s, and controversy remains over how effective they are in reducing bike fatalities. (Full disclosure: I bike to work whenever possible, and wear a helmet, an adherent to what a few cyclists I know like to call the Cult of the Styrofoam Talisman.)

So, Freakonomics readers, just how effective are bike helmets?