Pedal Power! Cycling Safety In Numbers

(Inside Science TV) – From biking to work, to school or just for fun, more and more people are peddling their way through life.

“I’ve been car-free for 23 years," said bike messenger Travis Culley.

Culley has been a bike messenger in Boulder, Colorado, Chicago and Philadelphia. He believes the more bikes around, the better off he is.

“I’m bicycling along other bicyclists," said Culley.

Now, civil engineering researchers have proof there is safety in numbers.

“When you have a lot of cyclists on the road, it’s almost like a traffic calming effect," said Wesley Marshall, a civil engineer at the University of Colorado Denver.

He and his colleague Krista Nordback from Portland State University in Oregon conducted the research.

They created a safety performance function graph for bicyclists. It shows the correlation between crashes at busy intersections, the number of bikes on the road, and the number of vehicles.

Researchers found that the risk of an accident was higher at intersections with fewer than 200 bicycles per day. One possibility is that with fewer cyclists around, drivers take fewer precautions.

“They’re less likely to look over your right shoulder when you’re making a right turn," explained Marshall.

Boulder keeps a close count of bikers and has designated bike paths throughout the city, along with clearly marked signs and signals to encourage bike riding.

But bikes are not just for small towns and small cities. In the last five years, New York City added hundreds of miles of bike lanes.

 “Cars are going just as fast and just as many cars are getting through … the number of cyclists has doubled and … it’s 30 percent safer now that it was before,” said Marshall.

The top five safest big cities for bicyclists are Portland, Oregon, Minneapolis, Seattle, San Francisco, and Washington, D.C.