Drivers pass closer to bicyclists wearing helmets than they do to bicyclists with bare heads, increasing the chances of collision.
As a result, bicycle helmets could indirectly increase the risk of serious injury from a bicycle accident.
Dr. Ian Walker, a traffic psychologist, fitted a bicycle with a computer and an ultrasonic distance sensor to obtain the data. He recorded distance information from over 2,500 passing cars, half the time wearing a helmet and half the time not.
Dr. Walker found that drivers were twice as likely to get close to the bicycle while he was wearing the helmet, and on average were passed more than three inches closer while he was wearing a helmet than while he wasn't.
Large vehicles, such as buses and trucks, also tended to pass considerably closer than cars. Dr. Walker was struck by a bus and a truck in the course of the experiment.
Because I'm fond of pointing out counter-cultural perspectives -- the stay-at-home mom myth is one of them -- I think you'll enjoy reading about this study.
By the way, if you're a woman, your luck may be slightly better. When the male researcher donned a long wig while biking, drivers kept a wider distance.
On a less lighthearted note, however, traffic accident statistics are fairly alarming, especially when you consider that, unlike certain diseases, these are preventable deaths. Here are some telling figures:
If current trends continue, road traffic injuries could be one of the biggest causes of preventable deaths by 2020 -- third only to heart disease and depression.
The largest number of accidents is caused by drivers looking at other accidents, traffic or roadside incidents. Other distractions, such as cell phone use while driving, are also a common cause. Some 98 percent of accidents are caused by a single distracted driver.
So play it safe; stay alert and attentive on the road, make sure you are well-rested and not driving while overtired, and be aware of pedestrians and bicyclists -- with and without helmets.