There's a new prescription for communities that want to make their streets safer for bike riders: just add more bikes. A team of international researchers looked at cities from Australia to Denmark to California, and found that more riders meant fewer run-ins with cars. The researchers presented their findings to a cycling safety seminar on September 5 in Sydney, Australia.

What's surprising, the researchers say, is that biker safety doesn't seem to correspond to a city's efforts to cut down on accidents. Run-ins between bikes and cars had little to do with miles of bike lanes or lower speed limits. But if the number of bike riders in a city doubled, the rate of bike-car accidents dropped by a third.

Apparently, motorists learn to share the road better when they have to deal with more bikes on their daily commute. Also, more cyclists means more drivers who also bike, which makes them better aware of fellow bikers. The researchers call it a virtuous cycle—run-ins with cars drop with more bikes on the road. And safer cycling means more people strap on a helmet and join the revolution.

—Adam Hinterthuer 

60-Second Science is a daily podcast. Subscribe to this Podcast: RSS | iTunes