Tom Fucoloro at Seattle Bike Blog has the skinny on the federal government's abandonment of a study that claimed bicyclists who wear helmets suffer significantly lower injury rates:

The often-cited and influential 1989 study was conducted in Seattle by Robert Thompson M.D. for Group Health. It has been heavily influential in discussions about municipal all-ages bicycle helmet laws. Not surprisingly, King County is among the only major metropolitan areas on the planet to have such a law. After all, if you could reduce head injuries by 85 percent just by wearing a helmet, then of course we should make them mandatory!

However, subsequent studies have not been able to repeat the 85 percent figure found in the Seattle study. Results vary, but have consistently been lower. After urging from the Washington Area Bicyclist Association in DC, the CDC and NHTSA will no longer be promoting the 85 percent conclusion.

The city should make riding without a helmet a secondary offense, which would help Seattle's bike share program get off the ground, Fucoloro says, because unlike helmets, "safety in numbers is 100 percent certain to lower the collision rate for people on bikes.

I think we should do away with helmet laws for adults altogether. Mandatory helmet laws discourage usage of bicycles. "Seattle's mandatory helmet laws are the biggest blockade to creating a comprehensive bike sharing program," local nonprofit Sightline found in a study last year. Four out of five bike share riders in Boston and Washington, DC, ride helmetless. Grist points out that the data is decidedly mixed on whether helmets provide significant protection from head injuries (some studies say it actually makes you less safe), but that that debate obscures the more important one over bike infrastructure.

I don't wear a helmet when I use my bicycle to get around Seattle. Friends and family worry and have been imploring me to wear one for years. Why subject yourself to needless danger, they ask? While I drafted this post, Eli wrote to me, "Wear a helmet! You make your living WITH YOUR BRAIN!"

And that captures the essence of choosing to wear one. It's driven by a climate of fear. Wear one or risk brain damage (the rest of one's body parts are, apparently, an afterthought). Wear one because I'm scared and you should be scared.

Obeying helmet laws in Seattle is a totally rational choice if you don't want to get killed or disabled. I'm not trying to be cavalier here. It is also, however, a protruding sign strapped on top of your head of submission to the status quo.

It shouldn't be like this. Berliners, with their 400 miles of bike lanes, aren't scared of being hit by a car. They—"old men," "young mothers [who] tow toddlers in trailers," among them—mostly do not use helmets, and there are no helmet laws.

I choose not to wear a helmet as an expression of prefigurative politics. I ride as if the city is as it should be. We should not have to ride in constant fear of being run off the road or holding up traffic when the bike lane disappears entirely or becomes shared with cars, trucks, and buses. Until we have a respectable degree of bicycle infrastructure in this city—cycletracks, protected bike lanes, bike share, and more—I will flout helmet laws. Until everyone (communities of color, older folks, parents and kids, the-less-daring) feels safe using bicycles to transport themselves about the city, I will flout helmet laws.

I look forward to one day wearing a helmet.