by Thomas J. Demarco M.D.

      Is bicycling really more dangerous than driving? Should we be forcing motorists to wear helmets instead? This analysis of the medical and environmental ramifications of bicycling vs driving suggests that it will take more than an inch of hard foam to achieve road safety.

      Thanks largely to physician advocacy, more and more cyclists in Canada and around the world are wearing helmets. Australia has gone beyond simply promoting them and has made their use mandatory. Shall Canada follow suit? Should it? The Canadian Medical Association thinks so. I disagree.

      As an environmentally-conscious general practitioner who cycles daily, I greet the growing debate about bicycle helmets with some ambivalence. They say any publicity is good publicity, so it's pleasing that so many Canadians want to discuss bicycling and bicycle safety. Still, I find much of the content of the debate rather disturbing, particularly the arguments being put forth by most of my medical colleagues. I believe that the ultimate political, social and medical ramifications of this issue are being largely overlooked.

      I have worn a helmet for probably 90% of the kilometres I've ridden over the past ten years. I feel more self-assured wearing one, perhaps a little too much so. The helmet allows me to wear an attached rear-view mirror, an added safety measure. My 95,000 km riding "career" has, thankfully, been accident- free so I cannot claim that the helmet has saved me from injury. But it does regularly save me from having cold rain and hot sun come into direct contact with an ever-more substantial bald-spot!

      In the event of a fall, having an inch or two of hard foam between one's skill and the asphalt is better than nothing. However, data to this effect are surprisingly scarce and inconsistent. I have seen statistics that bicycle helmets reduce fatalities by anywhere from 1% [1] to more than 50% [2]. The British Medical Association puts the figure at 33% [3]. Then how could any physician be against bike helmets? This doc sure isn't and is all for their promotion. However, I'm strongly opposed to legislation that makes their use mandatory.

      Doctors have often been accused, with some justification, of concentrating on treatment of symptoms and disease rather than promoting and maintaining health. The helmet debate reflects this unfortunate approach. I believe that most bicycle-related head injuries can be recognized as symptoms of a more malignant process: automobile dependence.

      Though largely ignored by medical care providers, it is increasingly evident that the principal alterable variables in with respect to society's health are lifestyle and environmental factors. Examples include air pollution, toxic waste, motor vehicle accidents, occupational disease, industrial accidents and stress. To them, we could add the concomitants of our sedentary existence: obesity, arterio-sclerosis, osteoporosis and maturity- onset diabetes. All these conditions are, to some extent, directly or indirectly attributable to our reliance on personal motor transportation. So too are some other major public health concerns such as the greenhouse effect, acid rain, ozone layer depletion and the Persian Gulf war. [4]

      With this in mind, let's return to bicycle safety debate. Riding a bike is obviously not without risk either. This risk, however, is almost universally overestimated by the general population. Again, the data are inconsistent and vary from country to country. I have not found reliable Canadian figures, so we'll look at the situation in two countries whose cycling conditions, in my opinion, are similar to ours. In terms of number of deaths per distance traveled, French research by Carre [5] showed no significant difference between cyclists and motorists while recent British Dept. of Transport figures suggest that the former are at an 11.4-fold risk [6]. Since children are heavily over-represented in bike accidents, their relative risk according to the British is probably greater than 20 whilst that of adult riders is less than 5. However, statistics such as these may lead us to overlook two fundamental considerations. The first is that motorcar use begets greater personal displacement. Newman and Kenworthy of Australia estimate that every kilometer traveled on public transport replaces ten kilometers of driving [7]. In Britain, regular cyclists travel only one-fifth as far as motorists (personally, I have experienced a similar reduction in my surface mileage since destroying my driver's permit). Per Trip, the relative risk of cycling then falls to 2.4 in the U.K. [8].

      The second "asterisk" that must accompany the bicycle's apparently unfavorable safety record is that worldwide, 90% of cyclist fatalities result from collisions with cars. "As a matter of fact," writes Ed Ayres of the WorldWatch Institute, "though bicycles outnumber cars globally by a ratio of 2 to 1, only two percent of the world's traffic fatalities involve cyclists. When bikes and cars are given each their own space, the risk of death is 500 times greater in cars." [9]

      So, bicycling is not as dangerous as popularly perceived. Furthermore it does not contribute to the aforementioned litany of personal and public health problems. Expressed in potential life-years gained versus potential life-years lost, Dr. Mayer Hillman estimates that regular cycling's net benefit to personal health outweighs its risk of injury by a factor of 20 to 1, even in a country as hostile to cycling as Great Britain [10]. Cyclists very likely live longer and healthier lives than non-cyclists and, unlike motorists, they incur no harm to society at large [11].

      Whenever someone chooses to cycle rather than drive, both personal and public health benefit. Cyclists, therefore, are allies of the medical profession. We should be doing all we can to encourage the activity. The British Medical Association actively does so (the BMA also promotes helmet use, but does not condone helmet legislation). Favourable publicity and other incentives have persuaded 50% of Ottawa's cyclists to wear helmets regularly [12]. I think such promotion is desirable, especially for high-risk groups like children and off-road riders. However, like the BMA, we mustn't support mandatory helmets, for at least 3 reasons.

      A move to compulsory headgear would reinforce the erroneous perception that bicycling is an unnacceptably dangerous activity. This is called " dangerization" [13]. Secondly, the measure is costly to cyclists, especially for children who should change helmets annually as they grow. An approved helmet costs one-fifth as much as the average bicycle; if seat belts carried the same relative price tag, they would cost more than $2,000 (the CMA's initiative in making available less expensive bike helmets is applauded). Thirdly, regardless of the fit or the weight, helmets (unlike seatbelts) can be quite uncomfortable, particularly in hot, humid weather. Even a regular helmet-wearer like myself was often inclined to remove it during a recent ride in Australia's warm Northern Territory. Largely because of these three factors, that country has witnessed a substantial drop in bicycle ridership once it passed its helmet law. Lately, Australia has devoted large sums of public money to projects and programmes designed to lure cyclists back onto their mounts [14].

      Rather than supporting helmet legislation, we'd be much wiser to address the ultimate source of most road fatalities: automobiles. As they've already done with tobacco, physicians should feel professionally compelled to show community leadership in discouraging car use. Calling for a ban on their publicity would be a good start. For a quick, substantial reduction in both cyclist and non-cyclist road fatalities, I suggest that doctors demand strict enforcement of lower speed limits. "Traffic calming" measures, which render speeding physically impossible, have already had a dramatic effect on accident rates in some European cities [15]. It is estimated by the Bristol Cycling Campaign that universal urban speed limits of 30 kph would save 1,500 lives annually in Britain [16]. We may also wish to reconsider the minimum driving age. Here in Canada it is still 16 years, but in Switzerland, it is set at 18. Perhaps 20 years would be even wiser. Measures like these would save many more lives than mandatory bicycle helmets ever will. So too would a helmet law for motorists, but of course I'm being facetious. Or am I? At the turn of the century, an Irish MP named TM Healy argued persuasively that if cyclists must bear lights then so must carriages and cars. Wouldn't the same logic apply to another safety measure?

      Henry David Thoreau wrote that if there are a hundred who would hack at the branches of evil for each one who attacks its root. Bicycle accidents are branches. Personal motor transport is the root. Rather than demanding helmets for cyclists, the medical profession's energies in the bicycle safety debate would be much more effective if directed at promoting bicycling itself. Increased participation in this activity would not only benefit the national health and environment, but also would contribute significantly to road safety. Cycling is not a problem -- it is a solution. We should not be discouraging it by advocating laws that will drive cyclists from our roads. Let us not risk killing the goose that lays the golden egg.

      1 Downing, C. "Pedal cycling accidents in Great Britain." Dept. of Transport, from Ways to Safer Cycling, 1988.
      2 Dussault, C. "Le casque protecteur cycliste: problematique, efficacite et relations avec les comportements Societe de l'assurance automobile du Quebec" and Perspectives Modiales sur le Velo, pp 313-317. Velo Quebec, Montreal, 1992.
      3 Hillman, M. Cycling Towards Health and Safety, p 82. BMA, London. 1992.
      4 It is commonly argued during the 1991 Gulf War that were it not for its car fleet, the USA would be self-sufficient in oil and hence would have had far less interest in initiating hostilities. For details of personal motor transport's contribution to the other conditions listed, refer to DeMarco, T. "The Most Dangerous Addiction? Why the Medical Community Must be Concerned About Automobile Dependence." Imagine, vol 1 no. 1
      5 Carre, J-R. "La situation de la bicyclette en France." Perspectives Mondiales sur la velo, pp 49-54. Velo Quebec, Montreal. 1992.
      6 see 3, p 46.
      7 Newman and Kenworthy, Towards a More Sustainable Canberra. Murdoch University, Perth. 1991.
      8 see 3, p 46.
      9 Ayres, Ed. "Breaking Away." WorldWatch Magazine. Jan-Feb, 1993.
      10 Hillman, M. Unpublished presentation at Velo Mondiale/Pro-Bike/Velo-City Conference, Montreal, Sept. 1992.
      11 see 3, p 111-121.
      12 Burdett, A. Personal correspondence. Ontario Coalition for Better Cycling.
      13 Krag, T. "Reflections on Safety of Cyclists and Bicycle Helmets." Velo Quebec, op cit. pp 334-337.
      14 The Australian federal government recently announced a $30 million investment for the construction of 600 kms of bike paths in 1993 by far its biggest annual expenditure ever for such works. The most recent data available from Monash University, Melbourne indicates that 2 years after the helmet law, the number of cyclists was approaching pre-law levels in adults and children, but was still greatly reduced in teenagers.
      15 see 7.
      16 New Cyclist. #30, Feb. 1993. London.

      (This article appeared in the Summer 1993 edition of Imagine, the newsletter of World Without Cars, a group based in Windsor, Ontario. The piece originally appeared in the Journal of the Canadian Medical Association).

November 2008
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