From Free Life, Issue 19, November 1993
ISSN: 0260 5112

The case for bicycle helmets appears compelling. If I bang my head walking through a low door, as I sometimes do, it hurts. If I were to do the same thing while running through the door I might knock myself out. If I were to be riding through the door at speed on a bicycle I might fracture my skull. If, in each case, I were wearing a bicycle helmet the pain or injury would be diminished.

There is a view that if cyclists are not sensible enough to heed this argument and wear a helmet, they should be compelled to do so. In recent years the campaign for compulsion has been gathering momentum around the world. In Australia and a number of jurisdictions in the United States the wearing of cycle helmets is already required by law; in New Zealand it will become compulsory in January 1994, and in Ontario a law has been passed that will take effect from October 1995. Such a law has a growing number of supporters in Britain. However, a new report from the Policy Studies Institute will take a lot of wind out of the sails

 of the helmet  
campaigners.    

The report, Cycle Helmets - the case for and against1, is by Mayer Hillman whose scientific reputation and qualifications in this field are attested to by the fact that he was chosen by the British Medical Association last year to write its report Cycling: Towards Health and Safety. In that report Hillman demonstrated convincingly the numerous health benefits to be gained by promoting cycling. Hillman's new report includes the most comprehensive review of the literature on the effects of cycle helmets ever undertaken. It discloses a remarkable dearth of evidence that helmets are effective safety devices.

Why should this be so? No one disputes that if you are going to bang your head you are better off wearing a helmet. But there now exists a compelling body of evidence from other areas of risk taking, that the use of protective equipment modifies behaviour.2 Climbers with ropes, for example, or cricketers and American football players with their helmets and pads, would pursue their sports much more carefully without these safety aids. The effect can also be seen on the road. If cars are fitted with better brakes, motorists do not drive in the same way as before and enjoy a wider margin of safety. They drive faster or start braking later or drive with less care and attention; the potential safety benefit is consumed as a performance benefit.

This response to protective equipment is known as "risk compensation." The effect is now well documented in the road safety literature; an OECD report on the phenomenon notes that it frequently frustrates the intentions of road safety planners: "behavioral adaptation is observed when engineers, programmers, and others make changes in the transportation system, and road users change their behaviour in a manner inconsistent with the goals of those initiating the change".3 None of the evidence cited by the campaigners for a helmet law acknowledges the existence of risk compensation.

Hillman also chides the cycle helmet campaigners for a lack of consistency. He points out that if helmets were as effective in preventing head injury as they claim, and if their aim is the prevention of head injuries, then they should begin their campaign with elderly pedestrians who account for more fatal head injuries than cyclists of all ages added together. Head injury fatality statistics show that children climbing and jumping and motorists of all ages also should be compelled to wear helmets before the law is applied to cyclists. Noting that there are three times more serious injuries to cyclists' arms and legs than to their heads, Hillman ironically advocates compulsory knee, elbow and shoulder pads as well. But 1 why stop there? Why stop before we all look like Michelin men dressed as American footballers?

The main effect of campaigns to persuade or compel cyclists to wear helmets has been to reduce the amount of cycling - a health-promoting and environmentally friendly form of transport. The cost, inconvenience, and discomfort of helmets all inhibit the use of what would otherwise be a very cheap and spontaneously accessible form of transport; in Australia after helmet use became compulsory cycling decreased by between 15% and 40%. In his study for the BMA Hillman noted that life years gained through the health benefits of regular cycling, even in the present dangerous environment, far exceeded life years lost in cycle accidents.

In the Netherlands and Denmark far more people cycle, few of them wear helmets, and fatality rates per kilometre cycled are between a quarter and a third of those in Britain. The way to make cycling safer is not to add protective armour to the cyclist, but to create an environment for cycling in which accidents are less likely to occur. Attempting to force people to be "sensible" by criminalizing self-risk not only denies an important freedom: it does not work.

Notes

1. M. Hillman, Cycle Helmets: the case for and against. Policy Studies Institute, London, 1993.

2. J.G.U. Adams, Risk and Freedom: the record of road safety regulation, Transport Publishing Projects. Available from the author at University College London, 1988.

3. OECD Behavioural adaptation to changes in the road transport system, IRRD no. 824028, Paris, 1990.