Search tips
Search criteria 


Logo of jrsocmedLink to Publisher's site
J R Soc Med. 2004 August; 97(8): 410–411.
PMCID: PMC1079574

In their paper arguing for compulsory use of cycle helmets1 Professor Sheikh and his colleagues accept that if compulsory helmets led to a long-term reduction in cycling the resulting bad effects on health could outweigh the reduction in head injuries. However, they offer only 'evidence in our possession' to suggest that the undoubted short-term reduction may not last. Can they be more specific?

There is something distasteful about a society's compelling some of its most vulnerable members (in the context of road safety) to protect themselves against the mistakes or misdeeds of the less vulnerable. Car seat belts protect their wearers in accidents which may result from their own or other people's actions, more or less indifferently, whereas serious head injuries to cyclists, against which helmets give some protection, are far more likely to result from something done by other road users.

I was sorry to see the authors commending the separation of cyclists and motorized traffic as a safety measure. We already have it by law on motorways and in the exclusion of the heaviest vehicles from some roads, and voluntarily in that most cyclists choose to keep off busy main roads when they can; but, unless somebody builds a duplicate network of real roads (not gravel tracks) all over the country and in all towns and villages, with the two systems never meeting at roundabouts, etc., cyclists and other users must share most roads. This can best be done if all users recognize that the others have as much right to be there as they have, with some bias by the less vulnerable in favour of the more vulnerable. Cycling in France, I have found drivers of all motor vehicles to be much more considerate towards cyclists than is usual in this country. I do not see why, with suitable education and persuasion, British drivers should not become more like French in this respect, making further segregation irrelevant.

A thought prompted by the article: seat belts give some protection to their wearers, and air bags give more, offset by the near-certainty of damage to the hearing of some accident victims (not to mention victims of spurious deployment). Helmets would offer probably better protection, with no bad side effects; they are routinely worn by participants in motor sports, including those in saloon cars. Compulsory helmets in cars would presumably lead to a reduction in car use, which would be good for the public health (less pollution, fewer accidents, more exercise). The case, on health grounds, is probably stronger than that for cyclists. The psychological difficulties are obviously enormous, but I wonder whether the general failure even to discuss the idea is another manifestation of our collective obsession with the car.


1. Sheikh A, Cook A, Ashcroft A. Making cycle helmets compulsory: ethical arguments for legislation. J R Soc Med 2004;97: 262-5 [PMC free article] [PubMed]
2004 August; 97(8): 410–411.

Authors' reply

Mr Wardlaw continues to overlook substantive evidence on the effectiveness of cycle helmets. A Cochrane systematic review of five well-conducted case–control studies concluded that helmets 'provide a 63%–88% reduction in the risk of head, brain and severe brain injury for all ages of bicyclists'.1 Furthermore, a wide-ranging review commissioned by the Department of Transport concluded: 'there is now a considerable amount of scientific evidence that bicycle helmets have been found to be effective at reducing head, brain and upper facial injury'.2 We are grateful to Wardlaw for pointing out a statistical error in our previous paper,3 however, a minor mistake in the discussion should not be allowed to divert attention from the main findings. During a period of increasing cycle helmet use the rate of serious head injuries fell, and by a greater margin than the decrease in a comparator pedestrian group. We suggested that the most plausible explanation for this difference was helmet wearing; Wardlaw offers no alternative explanation.

The effects of helmet wearing on injury rates have now been reported from several different countries. We wonder why Wardlaw continues to refer to Australasian data when more recent evidence has come from a large well-conducted study in Canada.4 Four Canadian provinces enacted helmet-wearing legislation between 1995 and 1997, while the remaining eight did not. From 1994–1995 to 1997–1998 cyclist head injury rates fell in all provinces, but the reduction was significantly greater in provinces that had legislated. Other injuries also fell in both sets of provinces, but the difference between them was not significant. The reduction in head injuries points to a benefit from helmet-wearing, while the similarity of other-injury rates suggests that patterns of cycling were not affected. Since Wardlaw questions the ability of others to grasp the big picture, these oversights are remarkable.

We have more sympathy with Professor Swanson's argument on the separation of cyclists and motorized traffic. It would indeed be better to change motorists' attitudes to cyclists than to allow the current attitude to persist. It might also be possible to confine at least some heavy goods vehicles to trunk roads. However, quite apart from the planning problems this proposal would present, a cycle helmet law would be far cheaper and quicker to implement.

This takes us to the ethical arguments. Swanson presents two: first, that it is unjust to impose the burden of protection on the vulnerable party rather (be that a child, or perhaps any cyclist) than on motorists; second, that it is irrational to concentrate on one risk (the risk of head injury to an unprotected cyclist) rather than any other comparable risk (for example, the risk of head injury to an unprotected motorist).

The second argument is weak. First of all, interventions to control risk should be assessed on the evidence. Our argument regarding the evidence is quite modest: we believe that the available evidence does support the proposition that cycle helmets are safe and effective in protecting cyclists from head injury. This is the essential empirical point in the ethical argument for legislation. We do not rule out other interventions to control other risks; they are not our concern here. Second, in the muddy world of public policy, consistency may be an impossible ideal. So long as policies can be justified piece by piece on their own merits, and so long as they do not lead to obvious contradictions or injustice, that is about as much as we can hope for. Arguments that we do not intervene in some other comparable cases—so why do we intervene in this case?—are arguments for never doing anything.5

The first argument is more important. It is a defensible principle in ethics that one should not blame or punish victims for the responsible or irresponsible acts of those who have harmed them. Swanson is right to say that many, perhaps most, injuries to cyclists are caused by others. However, it is also true that we bear some responsibility for taking care of ourselves. Prevention of injury takes primacy over apportioning blame for the injury; to an injured cyclist the knowledge that someone else was responsible is of little comfort.


1. Thompson DC, Rivara FP, Thompson R. Helmets for preventing head and facial injuries in bicyclists (Cochrane Review). In: The Cochrane Library, Issue 2, 2004. Chichester: Wiley, 2004 []
2. Towner E, Dowswell T, Burkes M, Dickinson H, Towner J, Hayes M. Bicycle Helmets: Review of Effectiveness. London: DETR, 2002;30
3. Cook A, Sheikh A. Trends in serious head injuries among English cyclists and pedestrians. Inj Prev 2003;9: 266-7 [PMC free article] [PubMed]
4. Macpherson A, To T, Macarthur C, Chipman M, Wright J, Parkin P. Impact of mandatory helmet legislation on bicycle-related head injuries in children: a population-based study. Pediatrics 2002;110: e60. [PubMed]
5. Cornford FM. Microcosmographia Academica. Cambridge: Metcalfe & Co, 1908. [] (accessed 24 June 2004)

Articles from Journal of the Royal Society of Medicine are provided here courtesy of Royal Society of Medicine Press