Dangerizing Bicycling: The Helmet Episode

I have written in other forums questioning the wisdom of mandatory helmet laws.  I’ll state right up front so nobody gets me wrong — I think bicycle helmets are good.  I wear one.  I encourage others to wear one.  But when the state thinks about saying “You have to wear one” it should really think it through.

I happened upon a new document from the Brain Injury Association of Florida.  In it is a table on causes for traumatic brain injury (TBI).  It compares motor-vehicle-related traumatic brain injuries.

I think that the state’s interest in such a matter should be to reduce the overall number of brain injuries, not to target the activities it thinks are most likely to result in those injuries.  One might be able to argue (though I don’t think you can) that cyclists are more likely to experience traumatic brain injury than automobile occupants, motorcyclists or pedestrians, but if the actual number of cyclist injuries is low, the state isn’t affecting many lives with its law.  And making cycling appear riskier than it is.

The table on page 22 shows that there are 1.5 times as many pedestrian traffic emergency room traumatic brain injuries as for bicycling.  Three times as many deaths for pedestrians. 2.3 times as many hospitalizations.  Comparing motor vehicle occupants: 32 times as many emergency room visits; 13 times as many deaths.  Comparing motorcycles: twice as many emergency room visits; 2.6 times as many deaths.

But there’s a wrinkle in the data.  This data only applies to motor-vehicle-related injuries.  A solo motorcycle crash is a motor-vehicle-related injury.  Pedestrian head injuries that don’t involve motor vehicles are rather rare.  But bicyclist head injuries that don’t involve motor vehicles are fairly common and wouldn’t be included in this table.

In another data source — the Florida Dept. of Health — we see that cyclist hospitalizations which do not involve motor vehicles outnumber those that do involve motor vehicles about 2-to-1.  So I inflated the bicyclist TBI numbers accordingly.  (Granted — this only a guess…)  With that adjustment, bicyclist traumatic brain injuries are about equal to pedestrians and motorcyclists.  (BTW, motorcyclists account for only about 1.4 times as many TBIs as pedestrians.)  But comparing to motor vehicle occupants, there are still nearly 11 times as many emergency room visits and 3.7 times as many deaths compared to bicyclists.

There’s some data that suggests mandatory helmet laws reduce cycling.  In metro Orlando, child cycling injuries plummeted during the years the helmet law was debated, passed and initially implemented.  That’s all injuries, not just head injuries.  Reduced child cycling is the best explanation (though video games and “stranger danger” could also be blamed; not just the helmet law).   Similar results were seen in Australia.

Assuming my estimates and assumptions are correct (and for now I won’t insist they are), a mandatory helmet law should be passed for motor vehicle occupants.  It would probably both reduce excessive motor vehicle use and substantially reduce traumatic brain injuries.

15 replies
  1. MikeOnBike
    MikeOnBike says:

    If the mandatory helmet law for motor vehicle occupants applied only for those under 18, it might actually pass.

    If it applies to all ages, you’re infringing on freedom. If it applies to minors, you’re protecting children.

  2. Rodney
    Rodney says:

    I wear a helmet in all my riding pursuits. Personal preference.

    Worse case scenario: A mandatory helmet use law for motorists would put more Earnheart, Jr’s on the road.

    Best case scenario: Less auto’s and more cyclists on the road!

    TBI is a serious issue, regardless of waht activity is the cause.

  3. Julius
    Julius says:

    Mighk… very fair interpretation of the data, and probably the first time I’ve seen video games “blamed” for a reduction in injuries.

    Though, rather than making everyone wear helmets all the time, maybe everything else should just be made out of soft pillows…. or foam.

  4. MikeOnBike
    MikeOnBike says:

    Rodney said “Worse case scenario: A mandatory helmet use law for motorists would put more Earnheart, Jr’s on the road.”

    Risk compensation is a possibility. If teens are required to wear motor vehicle helmets, would teen motorists be more reckless?

    I’m sure Mighk meant MV helmets to be rhetorical. But I’m not so sure it won’t actually happen, at least for minors.

  5. Mighk
    Mighk says:

    Would helmets make motorists reckless? I don’t know, but head injuries went up dramatically for motorcyclists when the helmet law was rescinded. Risk compensation already occurs due to anti-lock brakes, gee-wizz vehicle control systems, airbags and excessively forgiving roadway design.

    Re: the video game link: It’s not just kids’ bicycling injuries that dropped during the ’90s and early ’00s; child pedestrian injuries dropped significantly too. But the bike drop was steeper. In Richard Louv’s book Last Child in the Woods he mentions a kid who said he prefers to play indoors because “that’s where all the electrical outlets are.”

    You may recall a report some years back that showed places with child bicycle helmet laws actually saw increases in cycling head injuries. Risk compensation there? Not enough data.

    I’m not clear on why mandatory helmet laws for adults “infringe on freedom” while MHLs for kids do not.

  6. AndrewP
    AndrewP says:

    rambling a bit here with a couple thoughts …..

    Re the MHL for kids, it’s just one of those “feel good” laws that never gets enforced ……..

    Mighk said: Re: the video game link: It’s not just kids’ bicycling injuries that dropped during the ’90s and early ’00s; child pedestrian injuries dropped significantly too. But the bike drop was steeper.

    One thing that went up — weight. Kids went from playing outside and riding bikes to sitting on a couch indoors, and their weight increased dramatically as well. Wish I could find the stats ….

    On another note …

    There is an interesting phenomena called risk compensation that happens alot when risk-avoidance measures are taken. It’s a tendency in humans to increase risky behavior proportionately as safeguards are introduced, and it’s very common. So common, in fact, as to render predictions of how well any given piece of safety equipment will work almost useless. Further research has lead to hypothosis that each individual has their own risk-tolerance comfort levels. When a given activity exceeds their comfort level, people will modify their behavior to reduce their risk until they are comfortable with their level of danger — BUT!! if a given person’s level of risk drops too far below their comfort level, they will again modify their behavior. This time though, they will increase their level of risk until they are once again in their target zone.

    Re freedoms vs society good: I wonder ….. What will happen when automobiles can be computer controlled and driven? (I don’t hink this is too far away and may very well happen in our lifetime). Will there be a huge debate over individuals saying “can’t take away my freedom to drive myself as I like” vs the gov’t saying “we’ve reduced automobile accidents by 90% when allowing the computers to drive the vehicles, and this reduces insurance premiums, hospital costs, etc, etc, all good things for everyone”. Can’t wait to see how that will play out …….

  7. MikeOnBike
    MikeOnBike says:

    Mighk asked: “I’m not clear on why mandatory helmet laws for adults “infringe on freedom” while MHLs for kids do not.”

    That’s politics?

  8. P.M. Summer
    P.M. Summer says:

    Mighk is right on this.

    We have a mandatory helmet law here in Dallas, Texas. All ages. The police use it as “probable cause” to stop minority cyclists (that’s what an Asst. Chief told me). Anecdotal reports on the drop in cycling activity was about 30%. No studies were funded for real data, because the supporters didn’t want real data.

    All the cyclists I’ve personally known who’ve been killed on their bicycles (even two not involving motor vehicles) were wearing helmets.

    The efficacy of bike helmets to protect you in anything other than a stumble getting on and off your bike is one of the great lies promoted in exchange for Bell Sports monetary support. Some pretty big names in “bicycle advocacy” took that money. They are taking other people’s money today.

    P.S. I wear a helmet most of the time. Have since 1984. I wear a hat most of the time, too. Have since about 1956 (Davy Crockett Coonskin then).

  9. Steve A
    Steve A says:

    Frankly, I’m conflicted about bicycle helmets, regardless of the law. Intuition and anecdotes say they won’t hurt and might help. Real world data says the safety effect is small enough that it doesn’t clearly show up in crash data. Most of the research (pro OR con) is basically junk science.

    At best, bike helmets are a distant #3 in the order of things cyclists can do to help themselves. #1 is to learn to ride better & safer. #2 is to learn to fall better (Kung Fu). If you’re worried about cycling safety, it makes no sense to do #3 without also doing #1 and #2.

    FWIW, I wear a bicycle helmet – where & when it’s required. As somewhat of a contrarian, getting called “stupid if you don’t” prompts me to restudy the evidence and THAT reinforces the conclusion that my best bet is to wear a Snell rated helmet – when I drive…

  10. Mighk
    Mighk says:

    I have no doubt that helmets can save lives and mitigate serious injuries. My wife cracked her helmet in a crash before she met me, and I have a few other friends who’ve done serious damage to their helmets. I think club cyclists are more likely to put them to good use since they ride in packs at higher speeds.

    But it bothers me when good ideas are inflated into ideologies.

    A similar discussion on the LCI list a few years ago on the relative merit of helmets compared to other strategies led to the Five Layers concept, which can be found at:

  11. Thom Parkin
    Thom Parkin says:

    If only there was a real TEST for the priviledge to operate a motor vehicle!!

    When I first obtained my license (in 1973) a State Trooper rode in the car with me and directed me to drive, park, et cetera. That was an opportunity to ‘prove’ my ability to safely control a motor vehicle. It even included starting the engine!!!

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