Friday, October 19, 2007

Will bicycling to work get you killed?

Brian O'Brien in the Mission sends this in:
October 18, 2007

Bicycle commuting is on the rise, as evidenced by the following articles in, the Boston Herald, and USA Today. But if the idea of hitting the road on two wheels — with little to protect you from cars and trucks but good manners — strikes you as pretty risky, you aren’t so far from the mark.

Per kilometer, cyclists are 12 times more likely than car drivers to suffer a fatal accident, according to Rutgers University urban planner John Pucher and Lewis Dijkstra of the European Commission (the same study found traveling by foot to be 23 times more dangerous than driving, per kilometer). To put this finding in perspective, there were 785 bicycling fatalities on American roadways in 2005, compared to 4,881 pedestrian and 43,443 automotive fatalities that same year.

On the other hand, a Danish study found that people who do not bike to work suffer a 39 percent higher mortality rate than those who do. So, assuming you can avoid a fatal accident on the road, biking to work may actually help you live longer.

The risks associated with cycling decrease dramatically when more cyclists are on the road, and especially when those cyclists obey traffic laws. This second point is hammered home in this bizarre but brilliant 1963 bike safety film, “One Got Fat” (the eagle — or is it monkey? — eyed among you will have recognized a clip from this film in the Freakonomics video “Does Sport Cause Crime").

One thing “One Got Fat” doesn’t mention is helmet use — helmets weren’t widely used until the 1970s, and controversy remains over how effective they are in reducing bike fatalities. (Full disclosure: I bike to work whenever possible, and wear a helmet, an adherent to what a few cyclists I know like to call the Cult of the Styrofoam Talisman.)

So, Freakonomics readers, just how effective are bike helmets?

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At 5:36 PM, Blogger Michael Baehr said...

Rob, your one saving grace is that you at least quote things in full. I despise the title of your post. A couple notes:

There's an active debate about the usefulness of bike helmets, and you'll find it in any bike-related forum online. People argue that helmets protect from certain head injuries but may magnify others; that they promote more reckless cycling and close following by cars, that they mess up hair-dos, etc. etc. As always, the most effective way to not hit your head is to not crash. I wear a helmet because it's what I've always done, but it's the least important safety measure on my bike. The most important is riding cautiously and paying attention to road conditions, other vehicles, and the mechanical condition of my bike.

I think the most important point in the article you quoted is that the leading indicator in bicycle safety in any particular area is the number of bicycles on the road. In places like the Netherlands or Denmark, home to some of the highest percentage of trips taken by bicycle (and also the lowest per-capita helmet use), bicycle-related fatalities are at their lowest. In the United States, which has a correspondingly low percentage of trips taken by bicycle, fatalities are much higher. What makes these places different? Let's see...

In Europe, cycling is part of the common culture; people are raised to bike, drivers expect to see bikes, and people more or less know how to handle themselves on the road. In the United States, there's mixed messages everywhere. If you see a cyclist riding on the sidewalk, or riding against the flow of traffic (which is unfortunately common), he's been woefully misinformed how and where to ride his bike. In fact, those two are the most common cause of bicycle fatalities in the US by far. It's important to take that into account when you constantly rail against infrastructure improvements for cycling, based on the fallacious assumption that cycling is dangerous.

Cycling in the road, as part of traffic, is remarkably safe. Yes, bikes are vulnerable in collisions with cars, but traffic is a system that operates by a sane set of rules and the basic precepts of game theory: everyone wants to get where they want to go, nobody wants to get in an accident, and they more or less cooperate to make sure both of those things happen. Yes, freak accidents happen, but they happen to people in cars, too. Should we all abandon our bikes and get in a motor vehicle? It seems to me that the best option is to get more people on bikes; we'll not only have a safer environment for cycling, but we'll also have a cycling culture, where people know what to do and where to do it. The reduction in automobile trips will benefit everyone. Do keep in mind that 50% of trips in the United States are under 2 miles. Nobody but the most woefully obese, or disabled/elderly is incapable of replacing those trips with a bicycle trip. Most of these people have just been conditioned to believe that it's impossible or dangerous. Neither of these things have to be true.

I'll close with this; I've been riding a bike in San Francisco for the last year. I can count one close call with an automobile, which occurred at 4 AM with a visibly drunk driver (and there's not much we can do about those). In the same time, I have almost been run over many times as a pedestrian; it seems like the most dangerous option in this city is to walk. I can't count how many times I've entered a crosswalk and a driver with his head in the clouds has failed to note my presence, or someone has backed out of a garage or driveway without looking behind them. Given the fact that you walk and take public transit, I find it downright bizarre that you believe San Francisco is better off with more motor vehicles on the streets, moving at faster speeds.

At 12:50 PM, Blogger Rob Anderson said...

"Rob, your one saving grace is that you at least quote things in full. I despise the title of your post."

Only "one saving grace"? You have to admit that I also write clearly. The title of the post was just taken from the original article. That there's even any debate about whether it's helpful to wear a helmet is the kind of thing that makes those of us in the non-biking community question the judgment of you and you two-wheeled comrades. Read through the comments to the online comments on this article, and you find many tales of heads and lives saved by helmets. Yes, it's best not to crash at all, but that's not something you can really control on a bike, notwithstanding all your caution as a cyclist.

I think the fatality issue is a red herring. The real question is injuries suffered in general while cycling, about which there are only sketchy numbers. Even here in Progressive Land there are no hard numbers about how many people injure themselves while cycling. Cyclists of course play down the safety issue.

In the city, a mile-long trip on a bike is fraught with hazards, while walking or taking the bus is relatively safe. Again, that a handful of pedestrians are killed every year on the streets of SF is another red herring. When you consider the number of motor vehicles on the streets of the city vis a vis our population density, I just don't buy the claim that walking in SF is inherently dangerous. Besides, since we don't really know how many people are injured while cycling in SF in the first place, it's impossible to make a valid comparison.

It's simply untrue that I "constantly rail against infrastructure improvements for cycling, based on the fallacious assumption that cycling is dangerous." What I've said lo these many times is that cycling "infrastructure improvements"---that is, bike lanes---should be done very carefully in a relatively small city like SF with so many two-lane streets and busy boulevard-like main arteries. The whole point of the litigation against the city's Bicycle Plan was that there needed to be some serious environmental study---and traffic studies---before we take away traffic lanes and street parking to make bike lanes. I assume that, if the EIR on the Bicycle Plan the city is now working on turns out to be adequate, that the city will eventually make more bike lanes where appropriate in the city. If the city does a slap-dash job of the EIR, it invites still more litigation.

In short, I don't oppose improving the cycling "infrastructure" in the city at all. I'm saying that it has to be done very carefully, not imposed stealthily by the city and the SF Bicycle Coalition on city neighborhoods without proper notice and public debate, which is what the city tried to do.

But it's true that, regardless of the studies, I'm convinced that riding a bike in the city is an inherently unsafe way to get around in SF. Someone who argues that wearing a helmet while cycling is "the least important safety measure" he takes is unlikely to convince me or anyone else otherwise. Again, I refer you to the online comments of cyclers who have found their helmets very useful indeed in accidents they've had.

At 1:41 PM, Blogger Michael Baehr said...


Wearing a helmet is the least important safety measure I take on a bicycle and, as I previously stated, I wear a helmet for every trip. Even if I'm going a block, I don't forego the helmet.

When I look at bicycle safety videos from the 1950s and 1960s (very fascinating stuff), much like the one linked in the article, I find common sense instructions about cooperating with traffic, signaling, avoiding obvious road hazards, maintaining your bike, etc. These videos (targeted at young people) were also made when riding a bicycle around was the most common way for children and teenagers to travel (it was much more rare to have your own car as a kid back then than today), and a popular way to get to school. In the 1980s, when bicycle helmets hit the mainstream, the safety dogma pretty much changed to "wear a helmet, you'll be OK!". This also coincided with a real drop in people riding bicycles for day-to-day trips. Bicycles became toys, to be operated like toys, and the helmet nazis reinforced the idea that they were dangerous toys. And indeed I see plenty of cyclists wearing a helmet... while riding on the sidewalk, riding against traffic, riding in the blind spots of large vehicles, riding too fast for conditions, etc. Helmets give a wonderful false sense of security, as if they'll protect from any head injury (they won't), and as if most bike falls are to the head (they're not). Hell, most of the people I see wearing helmets haven't even adjusted the damn things properly.

It's great to wear a helmet, but it's no substitute for proper bicycle training. Helmets save lives, which is why I wear one, but not riding like a dumbass saves even more.

Otherwise, thanks for your reply. It's nice to know you read these things :)

At 5:25 PM, Anonymous Anonymous said...

"if you care about not imperiling others -- assuming you want to avoid both dying and killing in a collision -- then cycling looks substantially safer than driving, because bikers almost never kill or injure others. But even assuming you don't care about anyone but yourself, cycling is still the healthy choice, because crash danger isn't the end of the story.

Biking's health benefits massively outweigh its health risks."

At 8:43 PM, Anonymous Anonymous said...

Ahh the internet.., giving a platform to any angry old fart with a computer.

At 8:50 AM, Blogger Rob Anderson said...

And to a chickenshit---why the anonymity?---young twit with a computer. Could you cite an example of my alleged anger? Why bother to comment if you have nothing to say?


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