« Badly behaved cyclists in the Sun | Main | Beach Drive to close mid day today and tomorrow »


Feed You can follow this conversation by subscribing to the comment feed for this post.

This chart does not take into account what in economics is named "moral hazard". Basically, a change in behavior: taking higher risks when wearing a helmet since people feel safer with it (also very common with any type of insurance, and that is the rationality for the existence of coinsurance and deductibles). I normally wear a helmet, no matter what, but in the rare occasions that I have forgotten it, I am way way more careful while riding, which implies that I take more risks without a helmet...

"Moral hazard" fails to take into account the effect of assuefaction (let's call it "forgetfulness from habit"). I (almost) never wear a helmet and I commute by bike daily (20+ miles a day). After doing this long enough, I've forgotten all about whether I'm wearing a helmet, so my behavior is no longer influenced and I'm no more cautious or reckless than I would be if I wore a helmet. It's not deliberate, it just happens.

I don't worry about the arguments for and against the safety of helmets, but whether cyclists should be forced by law to wear them. To me, it should be a personal choice.

What Titania describes is acutally risk compensation. Moral hazard is when you are less careful because you know someone else will be bearing part of the risk -- for example, because you have insurance. Who are the biggest proponents of bicycle helmet use? It's not cyclists, for the most part they wear helmets if they want to and don't care what others do. It's motorists who want all cyclists wearing helmets. Why? For many, careful driving is just too much of a burden. They want to shift the consequences of their unsafe driving onto others.

On Friday evening I went to unlock my bike from a parking meter, where a woman was leaning smoking a cigarette. I politely said "excuse me," and she politely stepped out of the way. As I was putting on my helmet, she asked me if helmets were required in DC or if I was "just smart." I didn't want to get into a big thing about how I wear a helmet but don't begrudge those who don't but I do kinda wish I had asked her which she thought was less smart: riding without a helmet or smoking.

jj: I'm glad you didn't decide to insult the friendly smoker who implied that either the law is good or you are smart. The closest thing to ask if you needed a rejoinder would be: "Does your company make you smoke outside or are you just considerate..." except that question only makese sense in a tobacco state.

All I can say is, I might be dead if not for my helmet, having had a crash a few years back where I flew through the air and landed on my head.

When I get home I rest my helmet on my handlebars, so I can't forget to take it with me when I head back out.

Maybe I'm misreading the graph, but it makes it look like there are less head injuries after the law was passed, if you look at the the whole span between 1970-1998, but less so if you view the chart from 1989-1998. Of course, we'd need to know how they collected their data to know whether this graph is even reliable.

In any event, I agree with the comment by Blue Eyed Devil above that it should be a personal choice. We don't need more obstacles to getting people on their bikes.

Here's a thought though... The graph shows that the percentage of cyclists wearing helmets increased significantly. However, it doesn't indicate how many cyclists that was. Possibly, most of the inexperienced cyclists that were more likely to fall were no longer riding, leaving mostly experienced helmet-wearing riders. That could certainly account for the relatively level head injury rate.

The whole blog posting is excellent, but I want to draw attention to this quote:

Cyclists’ representative groups complain that focus on helmets diverts attention from other issues which are much more important for improving bicycle safety, such as road danger reduction, training, roadcraft, and bicycle maintenance. Of 28 publicly funded cycle safety interventions listed in a report in 2002, 24 were helmet promotions. For context, one evaluation of the relative merits of different cycle safety interventions estimated that 27% of cyclist casualties could be prevented by various measures, of which just 1% could be achieved through a combination of bicycle engineering and helmet use.

That to me is the crux of the problem with fixation on helmets. Helmets aren't bad, they just aren't terribly effective. And there are other things -- like lights -- which are effective.

Apparently people who don't wear helmets never ride on the streets where I do. I've been hit in the head by some pretty big branches without getting a huge bump on my head thanks to my helmet, and I regularly get thwacked in the head by smaller twigs, brush and weeds. Instantly tilting your head down so your helmet hits first is the only defense against whiplike twigs and vines you see at the last second.

Contrarian, I absolutely agree. Any time I see an article about bike safety and they spend more time on helmets than lights I get a little bit crazy. We aren't appling resources - and social pressure is a resource IMO - on the right things in the right amounts.

In my opinion ...

The best even-handed approach to helmets is at ...


Randy Swart's BHSI site also contains some excellent point. Although they are obvious pro-helmet.

More generally, there seems to be a growing body of evidence that serious brain injuries -- as opposed to head injuries -- are the result of rotational forces instead of linear forces which helmets likely exacerbate. Below is a literature review from 2003.


Are we allowed to agree with Contrarian? ;-)

That to me is the crux of the problem with fixation on helmets. Helmets aren't bad, they just aren't terribly effective. And there are other things -- like lights -- which are effective.

They should still be good at lessening the effect of ordinary bumps and falls that children tend to suffer. And linear impacts do hurt.

Are we allowed to agree with Contrarian? ;-)
Imagine how I feel. Think of how hard it is to be contrarian when people keep agreeing with you.

If we allow separate dedicated facilities for cyclists, safe from auto traffic, the need for helmets is not so great.
Other countries where there are great numbers of cyclists have lesser numbers of helmets users because the conditions for cycling are safer. force cyclists into roads "vehicular cycling" and we have much worse accident numbers. simple as that. "sharing the road" with cars and trucks is not safe.

w: in the US, over 85% of all cyclist accidents involve no other vehicle, they're caused by the cyclist either hitting a stationary object or falling off his bike. Even if we completely eliminated collisions with cars we would still have accident rates an order of magnitude higher than other countries.

Ironically, falls and stationary object collisions are the types of low-speed impacts that helmets are actually designed for and where they might be expected to actually do some good.

You need to stop this Contrarian.

Ironically, falls and stationary object collisions are the types of low-speed impacts that helmets are actually designed for and where they might be expected to actually do some good.

I believe helmets are designed to protect a head from a two-meter standing fall. (BHSI will have a full description of the test)

contrarian, I'm not sure where the 85% of accidents number comes from, but the vast majority of cyclist deaths involve a car.

Pucher and others have documented cycling accidents in different countries. Clearly it is exposure to mixed traffic that is at fault- bicycles and cars do not mix well. In countries w/ auto-protected infrastructure there are not only many many more cyclists, there are fewer accidents by far, and almost no helmet usage. However- I do happen to like the new Danish helmets- they look less like oddball bird beaks and more like normal hats. This is a big step in the right direction- better design- both ergonomic and practical needs to come about in cycling culture which will help with perceptions of elitism and exclusivity. The bike helmets we have now days here in the uSA are just FUGLY.

RE: 85% ...

My guess is that the figure is from here ...


My number comes courtesy of Ken Kifer's great page on bike safety, http://www.kenkifer.com/bikepages/health/risks.htm

He cites the CPSC and NHTSA as the source of his data,

we have two separate kinds of injuries, those involving motor vehicles, which I will call "collisions" or "crashes" for convenience, and those not involving motor vehicles, which I will call "falls" for convenience (even though some involve collisions with other cyclists or objects).

Per year:
58,000 injured in collisions
530,000 injured in falls.

Those are injuries that require a trip to an emergency room. He also provides stats for two other severities of injuries: requiring admission to a hospital (~17,000/year); and fatal (~800/year). He asserts without citation that 90% of fatalities are due to collisions with automobiles (and this is consistent with what others report). There is no breakdown of injuries requiring admission, but he also provides the NHTSA datum that 8,000 cyclists suffer "incapacitating" injuries as a result of collisions with cars, although no definition of "incapacitating" is given.

A study made by Voukelatos and Rissel, published in Journal of the Australasian College of Road Safety: The effects of bicycle helmet legislation on cycling related injury: the ratio of head to arm injuries. They studied crashes in New South Wales.

A cyclist could hurt his arms and head when falling down. With a helmet on, there should be less head injuries and the number of arm injuries should stay the same.

Their conclusion: There was a marked decline in ratio of head to arm injuries before the mandatory helmet law, most likely a result of other improvements to road safety. Helmet use is likely to prevent some head injury, particularly for younger age groups, and may also reduce severity of injury. However, mandatory helmet law appears not to be the main factor for reduction in head injuries.


Many of you may know this, but I thought I would point out the sad fact that Ken Kifer (whom w cites above) was killed when a drunk driver ran into his bike, back in 2003.

Apologies, it was contrarian who cited Kifer.

what is this graph actually showing? The principal point of the helmet is not as much to protect from head injuries but to protect from serious head injuries. A more telling graph would include changes in mortality following the helmet law. and what does % injuries even mean? Is that saying that in 1971 60% of motor vehicle drivers were walking around with head injuries?

See pdf 'Health and safety assessment of state bicycle helmet laws in the USA'

All I know is, my wife was t-boned by a car driving crossways in a parking lot; she left a helmet-shaped dent in the windshield before flying off the front of the car. Since then, we wear helmets every time we ride.

I always tell people, it's not because you're a bad rider, but because there are so many bad drivers.

Glad I missed the heat of this topic...

Last week my helmet caused me to crash - with injuries. Riding on a sidewalk (legally, of course) and at a slow speed, my helmet snagged a tree branch. It yanked me backwards off my bike, and I couldn't unclip until the bike landed on me.

I received minor road rash on my rear and one elbow, several bad bruises, and my back, neck, and throat were sore for several days. My weak ankle was also re-injured when the bike twisted to one side. My pump and my music player in my backpack were broken, and my coffee thermos in a side pocket was badly dented.

The helmet never touched the ground, so it provided absolutely no protection, and I wouldn't have had any trouble at all if I hadn't been wearing my helmet.

Ever since, I've avoided wearing one. I sometimes forget and put it on out of habit, but if I stick with it for a few weeks I think I'll have a brand new habit to keep me safe.

(For what it's worth, I'm NOT kidding one bit. In 20 years of riding I can only think of one time a helmet protected me, maybe, but that was a race situation. On the other hand, a helmet turned what should have been the safest, calmest possible ride into the third worst bike-related injury I've ever had. Never again...)

Google "Bible stops bullet." You'll find dozens -- hundreds? -- of documented accounts of people who were carrying a Bible that was struck by a bullet, leaving them unharmed or less harmed than they would have been if the bullet had hit them directly. Shouldn't we all carry Bibles around to protect us from bullets?

Contrarian - agreed.

As another example, a friend of my friend has a brother's cousin who was driving down the street and struck a truck head-on and flew through the windshield, narrowly missing the truck and landing on a soft pile of leaves.

If he had been wearing his seat belt, it would have killed him!

DaveS - mountain bikers say the same thing about bar ends getting caught on trees and debris. I'm not saying I don't believe you, because I do....and I'm not happy that you got hurt, because I've had stitches and road rash and it isn't fun.

But I couldn't even read your post seriously. Your personal example is just like any other -- a needle in a hay stack. I've fallen off mountain bikes and struck my helmet, and to my best knowledge, my head was probably protected in some way by striking the helmet instead of my skull directly. I suppose you could argue that the reason I fell was because I was riding more dangerously because I HAD a helmet, or that the added thickness of the helmet is what actually struck the ground, but it all sounds (and smells) like BS.

By all means, I don't really care if other people wear a helmet or not.

However, to argue that better bicycle safety is accomplished by NOT wearing a helmet is the dumbest thing I've read on this blog.

The late Ken Kifer, whose bicycling website I highly respect, also shared the negative view of bicycle helmet laws.

As much as I respect him, I find this part rather strange:

However, the evidence of dented and broken helmets is proof of nothing. After all, they are made of light foam with perhaps a thin coat of plastic. It seems that the helmet must have reduced the impact somewhat, but it's impossible to say how much, as many cyclists do land on their heads without wearing helmets and yet still walk away from the accident. In some cases, the size of the helmet may have contributed to its contacting the ground. In the case of those seriously injured while wearing helmets, one might equally argue that the helmet should have been stronger.


The last sentence is the one I find most interesting, because he probably meant it as argument for why helmets are not valuable, but to me it outlines that they must be of SOME value.

Anyway - just wanted to post that since it is another source arguing against something that seems so incredibly logical of a choice to me.


Fascinating point.

I've fallen off mountain bikes and struck my helmet...

When mountain biking in areas with lots of deadfall and overhanging branches, I actually find it safer to *not* wear a helmet. Helmets--particularly mountain bike helmets, with their visors--tend to reduce visibility of things above you.

Of course, I would never embarrass myself by offering this argument as some sort of anti-helmet rationale on a public message board.


I'm afraid I don't understand the graph. Is it supposed to be percent of head injuries from total number of hospital admissions for each of the 4 groups?

And what happened around 1985 to explain why the percent across all groups dropped so precipitously? I can't think of anything that would affect head injuries for everyone.

The graph is puzzling. I dug and found the article it appeared in originally here:


The caption is "Head injuries among cyclists and other road users admitted to
hospital in Western Australia."

The Y axis is the percentage of all admissions with head injuries. The author's hypothesis is that if helmets were effective, we would expect that the relative frequency of head injuries compared to other injuries would drop. This would control for changes in the overall injury rate that may be unrelated to helmet use.

The author notes that the relative frequency of head injuries has dropped dramatically for cyclists since the introduction of a helmet law. But it also dropped similarly for pedestrians, drivers and passengers. The explanation given in the text is "The procedure for patients with a short
episode of concussion has changed in that such
patients are not now admitted routinely."

Ah. Thanks for the info Contrarian. I'd wondered if it was something like that.

The comments to this entry are closed.

Banner design by creativecouchdesigns.com

City Paper's Best Local Bike Blog 2009


 Subscribe in a reader