Risk Compensation

Since the 1970s, it has become gradually recognised that a reduction of risk leads to compensating changes in behaviour. Straightening roads leads to higher speeds to the extent that chicanes are now often built into residential streets. Seat belt use reduces injuries to car occupants who wear them. However, when first introduced, the legislation applied only to front seat passengers and there was an initial increase in fatalities among rear seat passengers. There was furthermore an increase in the numbers of pedestrians and cyclists injured by belted drivers. There is evidence that drivers are more careful around helmet-less riders, presumably because they regard them as more vulnerable or more human. It would be consistent with the theory of risk compensation for helmeted cyclists to take less care including when around pedestrians.


Risk compensation provides a plausible explanation for why the population studies have failed to show any increase in the overall safety of cyclists where helmet wearing rates are increased.


Where the safety benefits are marginal, as in the case of cycle helmets, they are capable of being offset by risk compensation.


Convenience vs Comfort


If it is accepted that cycling is to be encouraged, then it is sensible to make it as convenient and comfortable as possible. In Spain, a mandatory helmet law does not apply when it is hot or when cycling in town or to a cyclist who is training (and is not enforced against anyone). The Velib scheme (short term hire from one cycle stand to another within a city) is a success in Paris, Dublin, London and many other European cities. It works in Barcelona because of the exemption on helmet use within towns. Tel Aviv, Melbourne, Brisbane and Vancouver are all planning such schemes but none has yet worked with an enforced helmet law. Velibs offer convenience and spontaneity, it is obviously counter-productive to condemn as being at fault the user who does not have a helmet on him.



Read next section ‘Distraction’

Support our work