Helmet law leads to drop in bike-related injuries

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13 Responses

  1. ely_peddler says:

    It doesn’t say how much bike use dropped after the introduction of the helmet law.
    If use dropped by 29% as well then the law’s only effect was stopping people cycling.
    It’s well documented that making helmet use mandatory is a barrier to people starting cycling and this is detrimental to their overall health.
    It’s better for you to ride a bike without a helmet than not to ride a bike at all.
    Making drivers responsible for the deaths they cause by introducing strict liability like other European countries would have a much more profound effect on the safety of cyclists than forcing them to wear a helmet. The latter won’t help you if you are run over by a 40 tonne truck after all, but if the driver knew he might end up in jail then that might make him pay a bit more attention in the first place.
    Oh and btw I wear a helmet when I ride.

  2. Fiona says:

    Good answer. But I believe the study did take into account variables such as the drop off of bike use. I do agree re big trucks and a need for a change in driver laws. Thansk for taking the time to give your input.

  3. Neil says:

    Hi Fiona,

    I find it hard to believe that we are still even having this debate. There can be no doubt that wearing a helmet improves the outcome in the event of an accident or fall.

    This continued opposition to compulsory helmet laws seems to be the preserve of a select group of roadies (when do you ever see a mtber without a helmet?), who unfortunately still hold sway in many of the influential cycling organisations and are living in the dark ages.

    I am sure previous arguments against seatbelts and a host of other road safety improvements used similar flawed arguments for years.

    The sooner we increase the use of helmets through education or legislation the better.

  4. Paul Jakma says:


    Be careful how you interpret this study, and take very careful of the limitations the study itself notes:

    a) Injury rates are seasonal, and they have only very limited data (less than a year) on pre-law rates.

    b) They assumed exposure to potential injuries was identical for head, leg and arms. While this seems a reasonable assumption, as they say, their own data shows this assumption may not be entirely safe.

    c) They have no data on cyclist types or behaviour, so they can’t factor out things like proportionally more cyclists in riskier environments having given up, or cycling in safer environments having increased (e.g. commuter v recreational cycling).

    If you study their findings closely you’ll note that the 29% decrease in injury rates only holds true for the few months around the actual law change. If you look at the data, figs 3 and 4 particularly, after the law change the head injury rates go on an *increasing* trend.

    For the per-population rate trend, head injury rates go from a decreasing trend, to an increasing one. By the end of the study period the head injury rates are almost back to same level (and still going up)! Interestingly, while arm rate trend seems to roughly match head injury rate, the leg rate steadies. Perhaps the general accident rate is somewhat stable, as per fig 2, and leg injuries reflects that), but people are having more head injuries per accident? Which would mean that the *nature* of accidents has changed, e.g., due to changes in cyclist and/or motorist behaviour – they do note that risk equalisation is a behaviour they havn’t accounted for.

    To me, this study appears to show that the law made a *short-term* improvement to an already decreasing head injury rate, but however has changed that head injury rate to an increasing one. Such that all benefits were already almost lost within just a year and half of the law change. Probably, if the upward trend continued, they likely ended up with *worse* head injury rates than before!

    So I don’t think this study shows what your headline claims. Other than in a very unusual period around a law change, this study seems to suggest helmet laws make things *worse*.

  5. Fiona says:

    Thanks so much for your comments. As ever this debate brings strong opinion from both sides. I always enjoy reading the points of view from both sides. I’ve just bought myself a lovely shiny new bike helmet and I’m enjoying wearing it. It looks good and shouldI fall off my bike I think it will help with protecting my brain!

  6. Fiona says:

    Awesome reply Paul. I can see all your points. It’s one of those debates that has strong opinion on both sides and I like to hear from both sides. At the end of the day it’s up to each rider (for now!) to make up their minds. I can see how studies are really hard to qualify because no rider will ever ride in the same way or do the same thing every metre of each ride.

  7. Paul Jakma says:


    The problem with wearing a helmet is that driver’s then tend to take more risks around you: http://bit.ly/jAxhUs. This is “risk equalisation” or “risk homeostatis”, one of the weaknesses in the study. The cyclist themselves can also be prone to this effect.

    So if you have an accident then, yes, you’re much better off with a helmet. However, you may be more likely to get into accident by wearing the helmet.

  8. Luke says:

    Fiona, I’ve read the study thoroughly and to me the evidence appears quite weak.

    The authors are not claiming that the QUANTITY of head injuries decreased nor are they claiming that the RATE of injury (per hour or per k/m) decreased either. All they found is that the ratio of head-to-limb injuries decreased by 25%-29%.

    This meant that they did not have to account for the decline in riding that most occurred when the laws came in (estimated to be between 20%-40%).

    Also they found the effect was not even persistent – the head-to-leg and head-to-arm injury ratios were both higher at the end of the sample 3 year sample period than they were at the start. To me this just highlights that many other things are just as or more important in reducing injuries than helmet use.

  9. Luke says:

    This is not to say that I think helmets do not provide some protection in the event of a crash (or that anyone should stop wearing them if they want to) but rather that the benefits are marginal rather than overwhelming.

    We have a very sad situation here in Australia now where police can (and do, very often) book cyclists for riding without a helmet in completely harmless situations (in parks and at very slow speeds for example). There is nothing like getting a $100 fine for riding a pushbike in the park to ruin your day and put a newcomer off riding.

    We have 2 bike schemes (Brisbane and Melbourne) which are both failing (they get only 5%-10% of the usage per bike than London, Dublin, Paris etc) because of the mandatory helmet law.

    So even if you wear a helmet 99% or even 100% of the time you should resists compulsion, because it has completely hampered the cycling culture here. It really needs to be left up to the individual to decide based on the situation at hand.

  10. Rich B says:

    I don’t know about anywhere else, but around here (SW U.K.) I’d say bike use has greatly increased in recent years. No, I don’t have figures, but I can see what I can see – more bike shops, more bike routes and cyclists on them, and far more cyclists on the road. Road cycling groups are common around here nowadays, there’s a big local MTB club with their own track in woods, and the people in these groups and doing activities that weren’t common years ago all seem to choose to wear helmets. The same seems true of individual non-club cyclists. It’s not mandatory to wear a helmet here, it just makes sense. Sure, if I’m pottering over the local grassy heathland the helmet may not be worn, but if I’m out on a track or the road it will be. Irrespective of cyclist numbers up or down and irrespective of the reason for a crash, if a single cyclist comes off then worn protection is going to offer protection and one head injury prevented by that is one head injury prevented and that’s a positive outcome. A helmet may have made a difference to a guy who I know fell off his bike for no apparent reason and died of a head injury, but as he didn’t have a helmet in those days (very very few did) there was not even a chance of that protective possibility. The increased risk of injury by not wearing a helmet in a crash cannot be denied, so nor can the reduced risk of wearing one in the same condition. In principle it’s no different than seatbelt use. I don’t think any other figure will alter what is fact – wearing a helmet offers increased protection and reduced likelihood of head injury for cyclists who come off. Why people come off is another issue.

  11. Fiona says:

    Thanks for your lengthy reply. Appreciated.

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