4 out of 5 of Bike Sharers Don't Wear Helmets

Bicycle-sharing programs are catching on around the country, which is good if you care about the environment, and bad if you care about people's skulls. A new study from Boston's Beth Israel Deaconess Medical Center found that about half of all cyclists and more than 80% of bike-share riders specifically don't bother with helmets, USA Today reports.

Researchers kept watch on 43 rental kiosks in Washington, DC, and Boston, keeping tabs on more than 3,000 riders. "Head injury accounts for about a third of all bicycle injuries and about three-quarters of bicycle-related deaths, so these are some pretty shocking numbers," the lead author says. He believes bike-share programs should make helmets more readily available at or near their rental racks. (More bicycle stories.)