Michigan Bicycle-Vehicle Crashes: Helmet vs. no-helmet

We produced a report showing bicycle crashes from 2004 through 2009  in Michigan and the degree of injury for each cyclist. We ran the report for cyclists with and without helmets.

For the majority of crashes it is not known whether the cyclist was wearing a helmet. We dropped those numbers. And in some cases, the police report said the cyclist was wearing a safety belt. We ignored those as well.

Only 40% of the police crash reports properly reported whether the cyclist was wearing a helmet or not. That shouldn’t be acceptable. Do we need an improved police reporting form or more training? We’re not sure.

But among those crashes that were properly reported, about 17% said the bicyclist was wearing a helmet in the crash.

Michigan Bicycle Crashes, 2004 – 2009

Degree of injury Helmet No helmet
Killed 1.4% 1.5%
Incapacitating 13% 11%
Non-incapacitating 38% 37%
Possible 36% 37%
No injury 10% 13%
Unknown/error 0.8% 1.1%

Now, let’s look at just the adult cyclists 18 and older. Helmets were worn in about 23% of the crashes.

Michigan Bicycle Crashes, 2004 – 2009, Adults only

Degree of injury Helmet No helmet
Killed 1.5% 1.9%
Incapacitating 15% 12%
Non-incapacitating 37% 35%
Possible 36% 39%
No injury 10% 12%
Unknown/error 0.6% 0.7%

One conclusion to make is that there isn’t much difference in injury severity between those wearing a helmet and those that are not. There’s a slightly higher fatality rather for non-helment wearers but helmeted cyclists do suffer from higher injury rates.

However, there’s not enough information to say these differences are due to helmet use.  Experience, risk taking, riding styles, rural vs. urban roads and more all play a role in the types of crashes that occur. A study would need to remove those factors to really determine the affect helmets have on injury severity.

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8 Responses to “Michigan Bicycle-Vehicle Crashes: Helmet vs. no-helmet”

  1. Gary Says:

    You saw this report last week, right? Helmet Wars: A gripping account of the great bicycle helmet campaigns http://bit.ly/fSNSCB It’s packed full of studies and resources.

  2. Todd Scott Says:

    @Wheelhouse Detroit had posted that on Facebook. That’s was motivated me to take a look at the stats.

  3. In this season of miracles, a former pro and his son could use one of their own « BikingInLA Says:

    […] 2011; somehow, I think the new Quiznos Pro Challenge will be just a tad more important. A look at helmet use in Michigan doesn’t show much difference in collision outcomes. How is it that Pittsburgh gets a bike center […]

  4. More data on helmets | Over the Bars in Milwaukee Says:

    […] Michigan Bicycle-Vehicle Crashes: Helmet vs. no-helmet […]

  5. Bill Says:

    This summary makes some confusing statements vs data presented.
    The statement “helmeted cyclist do suffer more injuries overall” isn’t supported by the data presented. Your % data shows the opposite is true in terms of injury rate. The % with no injury and/or possible injury is 2-5% lower for helmeted cyclists.

    If your statement is based on the actual occurrences of injuries (rather than % rates), that statement could make sense. If the proportion of riders wearing helmets is larger than those not wearing helmets, and if they had identical injury rates / rider, you’d expect more injuries from the bigger group (helmeted riders). Also, I’d guess that helmeted riders put in more miles… racers, club riders, triathletes are usually required to wear helmets to compete / participate in club.

  6. Todd Scott Says:

    You’re right about “more injuries” being misleading. I’ve corrected the post to read “helmeted cyclists do suffer from higher injury rates.” We’re looking at the distribution of injury severity and not the total number of injuries.

    However, cyclists without helmets in crashes are more likely to report having “no injury” than cyclists with helmets. As mentioned in the post, that doesn’t mean the helmet is the reason why. It could be demographics as you mention. Then again, one could look at whether cyclists without helmets are more likely to ride against traffic, on sidewalks, at night without lights, or just be less experienced overall. We know riding behaviors cause more crashes.

  7. Brian Says:

    A friendly note: please cite your sources of data when publishing articles with data anaysis.

    Thanks!

  8. Todd Scott Says:

    Brian, The data is from the Michigan State Police Office of Highway Safety Planning, and more specifically, their Michigan Traffic Crash Facts Data Query Tool.
    http://www.michigantrafficcrashfacts.org/datatool/build

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