A recent Canadian study found that bicycle helmet laws had little effect on head injuries. The study analysed 14 years of data, comparing provinces with and without helmet laws. Unlike other studies in this field, it attempts to remove the effect of confounding factors by controlling for background trends and modelling head injuries as a proportion of all cycling injuries. It concludes:

the incremental contribution of provincial helmet legislation to reduce the number of hospital admissions for head injuries is uncertain to some extent, but seems to have been minimal.

This study has been reported here:

“(the study) analyzed the rate of cycling-related hospital admissions for head injuries across the country between 1994 and 2008 — an enormous research sample of more than 66,000 people…

What they found initially seemed to suggest that this legislation improved public safety…

But upon closer inspection, according to Dennis and company, this positive effect failed to stand. On the contrary, the researchers concluded that head injuries were decreasing across the country at a rate that wasn’t “appreciably altered” by the new helmet laws. Other rider health initiatives — namely, public safety campaigns and the introduction of better bike infrastructure — rendered the contribution of helmet laws “minimal” …

Mandatory helmet laws, meanwhile, may discourage riding to the point where public safety as a whole suffers from the relative decrease in physical exercise.”

The effect is consistent with an analysis of cycling fatalities in Canada, that concludes:

It is apparent that mass helmet use is not contributing to the reduction in cyclist fatalities, at least not in any measurable way. The results suggest that traffic authorities should refocus to put their efforts into other proven measures.

The study contradicts other studies that had claimed a benefit from helmet legislation in Canada. However, many of these studies have serious methodological flaws rendering their claims invalid. Often, such studies are done by helmet advocates keen to “prove” their beliefs, with a disturbing lack of scientific discipline.

This has led Ben Goldacre, an epidemiologist, to provide an insightful overview of the challenges of evaluating the effectiveness of helmet legislation:

Standing over all this methodological complexity is a layer of politics, culture, and psychology. Supporters of helmets often tell vivid stories about someone they knew, or heard of, who was apparently saved from severe head injury by a helmet. Risks and benefits may be exaggerated or discounted depending on the emotional response to the idea of a helmet. For others, this is an explicitly political matter, where an emphasis on helmets reflects a seductively individualistic approach to risk management (or even “victim blaming”) while the real gains lie elsewhere. It is certainly true that in many countries, such as Denmark and the Netherlands, cyclists have low injury rates, even though rates of cycling are high and almost no cyclists wear helmets. This seems to be achieved through interventions such as good infrastructure; stronger legislation to protect cyclists; and a culture of cycling as a popular, routine, non-sporty, non-risky behaviour.

Helmet laws are ineffective compared to other safety measures. As the safest cycling countries demonstrate, other measures are far more effective to reduce injuries. Helmet laws seem to contribute little to safety, while reducing cycling and taking the focus away from more effective measures.

Opinion

Here are the reflections and impressions of a US resident who has observed the emergence of bicycle helmets in the United States over the last 40 years. While many of these observations cannot be confirmed without dedicated investigative journalism, they are informed by decades of attention to news articles, bicycling publications, bike organization policies, plus conversations and other interaction with helmet lobbyists.

Frank Krygowski is a retired professor of Engineering Technology, and a lifetime commuting, utility, recreational and touring cyclist.  He is active in cycling advocacy on the local, state and national levels.

Personally, I think U.S. helmet laws arise from a combination of factors. Here’s my completely undocumented impression of the history of bike helmets in the U.S.:

1. First, we had a culture in which there is no history or tradition of bicycling. Until the 1970s people thought bikes were only for kids. Very few adults rode at all, and only an infinitesmal number rode for utility or for sport.
2. Second, we had a big bike boom in the 1970s. Suddenly there was a huge upsurge in novice riders, most of whom knew very little about cycling, and (worse) did not realize there was anything to learn.
3. Third, some very opportunistic companies – primarily Bell Sports – realized that there was a market among all these new, easily-misled bike riders for a high-profit special hat. (And seriously, people do have an immense psychological urge to wear special hats! Gardeners, sailors, cowboys, baseball fans, military personnel, fishermen and countless others revel in their own stylish and “useful” headgear.)

Bell began a campaign of misinformation, claiming that any bike rider could easily fall at any time, then suffer a truly debilitating brain injury; and that therefore, smart cyclists always wore helmets. There was never any consideration of whether this possibility was at all common, or worse than for other common activities. Bell backed this effort up with very slick and generous ads in low-profit-margin bike magazines, plus (I’m guessing) some back room politicking.

Soon bike magazines showed fewer and fewer photos of bareheaded riders, giving the impression that any “serious” (e.g. club or racing) cyclist always wore a helmet. About this time, “Always wear a helmet” became the first rule of bicycle safety.

This gave Bell some decent profits. But eventually (due to a change in management, I believe) things suddenly pushed further. Bell produced a helmet not for enthusiasts, but for kids, and increased the “danger! danger!” hype. And critically, Bell began donating heavily to Safe Kids Inc., with (doubtlessly) more back room politicking. This was the real genesis of mandatory helmet laws for kids. The national Safe Kids organization began working to convince local chapters, parents and lawmakers that riding bikes (and any other wheeled toy) was as dangerous as juggling chainsaws. “If only one child can be saved…” became a battle cry.

I think this is what caused the surge in statewide MHLs through the 1990s. Since then, things have cooled off quite a bit in the U.S. Most helmet laws are not really enforced, from what I observe. Safe Kids has – for whatever reason – made car seats their prime issue instead of bike helmets (although of course, they still call for bike helmet use). Now we seem to deal with only two factors:

1. One factor is a cadre of do-gooders left over from the 1990s who have made helmet promotion one of their life’s guiding principles. Randy Swart is probably the prime example, but I suspect most American bike clubs have one or more local examples. These people will probably never admit that they wasted their time on a counterproductive effort. Data will mean nothing to them.
2. Another factor is that the efforts of Bell, Safe Kids and the do-gooders have worked, in that a very large number of Americans really do believe that a simple bike ride imposes a huge risk of serious brain injury. Oddly, this impression seems greater in higher-income areas, where the little suburban princes and princesses must be guaranteed to rise to their highest creative and earning potential. I suspect, though, that this population can be swayed by data, logic and fashion. This is a group that might eventually be convinced that ordinary bicycling is not dangerous, and has benefits that greatly outweigh it’s tiny risks. Even without a special hat.