Stephen Rees's blog

Thoughts about the relationships between transport and the urban area it serves

Do bike helmet laws really save people?

with 7 comments

A really balanced and thoughtful opinion piece from the Washington Post. The answer is not nearly as much as the helmet law proponents would have you believe:

Helmets are sometimes said to reduce the risk of head injury by 85 percent, but that statistic comes from a 1989 study that has not been replicated. “Studies in the last 20 years have calculated that helmets prevent 10 to 40 percent of head injuries,”

But this is in the context of states which do not have such laws, deciding whether or not to introduce them, and mostly they will only apply to children.

“No one would argue that helmets don’t decrease the risk of injury,”

Actually I think I might. For instance I often see cyclists who have a helmet on that will not do anything to protect them. That is because they do not wear them properly. Add to that the poor design of even the best helmets – which have not changed very much since standards were established – which do very little to protect against concussion. Moreover, many people do not replace their helmets often enough – or when the helmet gets damaged. If you have a helmet on, you won’t get a ticket is about the best advice I can give people here. But I am not at all confident that in the event of a collision the helmet will make a great deal of difference. What we do know is that helmet laws reduce the number of people cycling – and they deter the safest cyclists. They also get in the way of successful bike sharing programs, which otherwise are very good news for getting more people to cycle. The big killer these days is not collisions – its the diseases caused by inactivity: obesity, diabetes and heart disease. The metabolic syndrome of industrialized high calorie food (loaded with salt, sugar and fat), high levels of car use and widespread computer use for work and (with tv and video games) leisure time. Helmet laws make people think that cycling is dangerous, when not cycling is more dangerous. While the US can still avoid most of the silliness by sensible analysis of the Canadian data

overall rates of head injuries were not appreciably altered by helmet legislation.

we have the much harder problem of getting rid of the law we have. And at the same time persuading children that they ought to wear helmets – and that we need much better helmets, which people can wear if they want to.

PS And also see Feds Withdraw Claim That Bike Helmets Are 85 Percent Effective from the Washington Area Bicyclist Association as well as this post from Gordon Price on what ought to be the definitive study from New Zealand

Written by Stephen Rees

June 4, 2013 at 9:20 am

Posted in cycling

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7 Responses

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  1. Effectively very good article, where we learnt that, the 85% claims, violate the US Data Quality Act…Yes in US they have a data quality act..,. What happen in BC?

    Check this tweet of our VCH, which they spam everyone questioning helmet law with it:

    @erik_griswold Research shows that safety approved helmets reduce the risk of brain injury by over 85%— VCH Healthcare (@VCHhealthcare) May 31, 2013

    Click the link to see what is their source to back up the 85%…
    Yes, it is an automobile advocacy lobby…
    May you believe it: the VCH back its claim an anticycling law, from a automobile group lobby opinion…

    which also believe that photo radar doesn’t improve road safety (needless to say, virtually, all European countries disagree! and they have solid data to back their viewpoint!)

    Data quality, is clearly not what bother the VCH…Does ethic and deontology are known word at VCH?


    June 4, 2013 at 9:09 pm

  2. Thanks for this post. The level of disinformation concerning the risk of cycling is really breathtaking. The classic study of cycling risk was by Andersen in 2000, and found that commuter cyclists in Copenhagen had all-cause mortality about 30% lower than non-cyclists, even after controlling for many factors like leisure time exercise. Cycling is far safer than driving, and banning ordinary forms of cycling to save lives is ridiculous.

    I did some calculations of my own, based on standard data, and presented my results at last June’s VeloCity Global conference. I found that helmetless cycling has about 98% of the health benefit that helmeted cycling has. I also found that the health costs and benefits of a helmet law will balance if the law reduces cycling by about 0.5%, assuming optimistic estimates of helmet effectiveness. It’s virtually certain that BC’s helmet law has had a net health cost.

    Dr. Richard Johns

    June 4, 2013 at 9:25 pm

  3. The fall, the Washington reporter, Christie Aschwanden, has experimented, was looking probably like this one:

    always spectacular!

    …but you can also see how admirably our human body works at protecting our head:
    basically, You will use your arm and chest to amortize the fall first, ..
    You can end-up with severe damage on your body non vital part… this to preserve its vital part.
    (in martial art, like Judo, we capitalize on this body reaction for fall reception, it is called Ukemi).

    What could have happened if the cyclist was wearing an helmet?
    As noticed by the washington reporter, no less damage! (The body could have reacted in exactly the same way: exposing less vital part to preserve the most important ones). but may be more damage:

    The helmet increases exponentially the volume of the head,
    the Chinese cyclist has amortized the fall with its chest and arm, helped by a neck torsion to keep the head of the ground…according to the helmet volume/shape, there is great chance, that the helmet could have touch the ground first, incurring great damage on the helmet, and no less impressive damage on the rest of body.

    Pro helmet choir, will then feel allowed to say: “see Mom, how the helmet saved his life!”

    When in fact it could be the reverse, again, because the human reaction system didn’t anticipate the volume of the helmet, this one force an extra torsion between head and body, resulting in an increased risk of neck injury.

    On cyclist accidentology: Canada and BC doesn’t have any good data (at least publicly available).
    But generally, it is good to make a difference between

    -recreational cyclist and utilitarian cyclist (you don’t see this difference done in any canadian study AFAIK).
    -urban cycling vs rural cycling (again there is no difference done in Canada, AFAIK)
    -Bike share user vs other users (“”)

    And more generally: some important discriminatory factor
    -What is the proportion of intoxicated cyclist in the cycling fatalities?

    Where people has bothered to inquire (that is Ontario, Maryland, or Paris), they end up to find 30% of dead cyclists were intoxicated…(which is an underestimation, because blood test is usually not done immediately, or considering only daytime accidient, like in a Maryland study).
    I could be not surprised number run higher in BC, where you will have no time to correlate high cycling modal share with alcohol issue, in rural BC.

    Typical number are like below:

    Intoxicated cyclists have 5 times less chance to wear an helmet than non intoxicates ones; but have 10 time more chance to get an accident

    Ideology is not absent of science, and you will have easy time to find out, that the above finding is a reason to have a mandatory bike helmet law…is it ridiculous proposition?

    Judge by yourself:

    Intoxicated driver have 3 times less chance to wear an helmet than non intoxicate; but have 5 time more chance to get an accident

    Is it a reason we have seatbelt law? obviously not: first this statistic is done with already seat-belt law in place, second intoxicated people will not care about any laws.. Is it the reason we have strong legislation against DUI? absolutely…and still for cycling…

    When you take all the above parameter in consideration – consider alcohol the reason for death of drunk people, and not the lack of helmet!- you will end up with much sobering statistic on the effectiveness of the helmet law…

    By the way, increase in cycling mode share in BC, has not translated in more helmeted people (share of helmeted people has decreased from 70% to less than 60%): In clear increase has only been possible because the law stay largely unenforced, beside may be by the VPD,…what make also your point.

    On this last topic:
    I am surprised and regret the apathy of the cyclist organizations, namely HUB and the BC Cycling coalition…

    Beside disregarding basic issues, like passive safety-Hub even showcased a “suicide bike”, with no bell and other safety devices for its “biketowork campaign”- they are mesmerizing on many secondary issues or leading campaigns on how our tax $ could be increased to fund “cycling infrastructure”…but the reality is that all that makes no good sense at all as long as we have an helmet law in place.

    Take the bull by the ball please!

    I appreciate and support the very good work of “Vancouver Cycle Chic”, and “”
    they do great job at encouraging people to ride helmet free, it is certainly the best way to put more people on the bikes…and everyone can see it works…for the benefit of everyone!


    June 4, 2013 at 10:30 pm

  4. I rode bikes for years in the Bordeaux area, crossing the only bridge they had at the time…meaning that both sides of the bridges were a total mess of cars, trucks, motor bikes, bikes…I was in my mid-teens and my parents worried about all sorts of troubles I could get into, like following strange people into a deserted church (I wasn’t that stupid).
    Riding bikes in town was not on their long list of appalling dangers.

    We had no helmets then…and even today few Europeans, Japanese etc. bother with them.

    HOWEVER there is a huge difference between here and over there.
    In Vancouver far too many bike users think that they must ride as fast as possible and that they have the right to ride on sidewalk at full speed, and also use major streets that to me look extremely dangerous for bike riders.

    Over there urban bikes riders wear normal street clothes and ride at a leisurely speed, for a relatively short distance. On longer distances they park their bike and take transit..One see quite a lot of elderly bike riders, and I mean elderly (over 80-85). We don’t see that here.

    In rural areas people ride bikes on secondary roads or even country lanes.
    Until the advent of the divided motorways, that are mostly all tolled, practically no one dared ride bikes on the national roads that, at least in France, were quite dangerous.
    Most only had 3 lanes: one in each direction on the sides, the central lane being “the suicide lane” as cars overtaking slower cars in BOTH directions had to share that central lane and some drivers played chicken.

    Would I be foolish enough to want to ride a bike in Vancouver I would wear a helmet, knees and elbows pads, and perhaps a thick padded vest and pants..and still wouldn’t feel safe.


    Red frog

    June 4, 2013 at 11:15 pm

  5. regarding helmet laws, Isn’t it the elephant in the room that, if the goal is really to prevent as many accident-related head injuries as possible, far far more would be accomplished by enacting a law requiring all motorists to wear helmets while operating a vehicle? Compared to bicycles, there’s a couple of orders of magnitude more head injuries from automobile accidents…


    June 6, 2013 at 4:06 pm

  6. I think all urbanites can agree that mandatory helmet laws like the one in BC and Seattle have failed. Here is the economic side of the argument, each kilometer cycled saves society 21 cents in reduced health care costs even with 2 cents of increased crash costs factored in. This compares to 1.8 cents/km that motor vehicle operation costs society in health alone.

    Helmet wearing does not prevent 88% of head injuries, and similar myths are debunked here: and here: .
    Helmet wearing may produce a false sense of safety for the bike rider, thereby causing her to ride more aggressively. Helmet wearing causes the motor vehicle operators passing the bike to believe that the person is more resilient, so the car will pass more closely and quickly. Even in the event of a crash, helmets increase the likelihood of a more severe rotational head injury.

    If there is such a debate on bike helmets, I think there should be an equal debate on motoring helmets (just like nascar drivers wear helmets).


    June 8, 2013 at 11:18 pm

  7. You guys clearly don’t live with someone with a cycling related head injury, haha. Actually what concerns me more is LIGHTS. why isn’t there a law requiring cyclists to use proper, bright lights at dusk/night? I wouldn’t drive without my headlights at night-I don’t trust others to see me. Seems like many fatalities happen at dawn/dusk.. through a windshield the lights tend to obscure the area past their halo. One thing I have always wondered…why the blinkers? Why not cast a beam? Wouldn’t that be fairly easy to do using the pedaling for power? The BEST bike thing I EVER saw was while stopped ata stop sign… bike coming along McLean heading south behind woodland park. It was pitch black and the bike was freaking glowing electric blue!! It was the frame and it was beautiful. NO ONE could miss that, did some research and I think it was glow in the dark paint, but a newer technology, only ten minutes to charge up and can glow for up to 12 hours. Soooo awesome. Would probably be a great theft deterrent too! Cyclists, get on it!
    Ps.. at least the ticket is only 29 bucks, geez Louise, we all pay somehow. Besides, a sense of entitlement is far more dangerous than no helmet. Let’s keep it real like Harvey would say.


    July 17, 2013 at 12:24 am

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