The island of Jersey has become the first part of the British Isles to make helmets compulsory, with a £50 fine for the parents of all under-14s who are caught bareheaded on a bike.

The decision to impose a law was agreed in principle in 2010, but legislation only tabled for scrutiny early this year.

CTC is disappointed that legislators on the island have decided to prioritise this measure, instead of focusing on more crucial issues to improve cycling safety: for example, the design of infrastructure and enforcement of existing laws regulating driver behaviour, such as speed limits.

Why shouldn't helmets be mandatory?

Evidence making the case for the law was presented by in a hastily compiled 50-page report by consultants TRL. It argues that:

• Helmets, and helmet laws, are effective at reducing cyclists' head injuries;
• Evidence that helmet laws reduce cycle use are doubtful, and that a fall in cycle use due to a helmet law on Jersey is unlikely to occur.

There is a body of evidence which questions the strength of the first point, while the second point is very contentious indeed. Unfortunately, TRL's report was published only one day before the States of Jersey voted for its helmet law, giving groups like CTC no chance to comment on it before it was voted on. This was despite CTC having co-ordinated a joint letter also signed by British Cycling and Sustrans, seeking an opportunity for Chris Boardman, health experts and others to present evidence to the States of Jersey, before the decision was made.

The arguments for and against cycle helmets are interminable, conflicting and often heated. CTC's position is that helmets are up to the individual, but we fear that effort placed on mandating helmets and advertising them could make cycling appear more dangerous, and less attractive to everyday cycling. This is crucial since the justification for investing significantly in cycling comes mainly from substituting ordinary trips - to school, to work or for shopping - rather than for leisure. The public health crisis of physical inactivity is best dealt with by changing daily patterns of existing movement from sedentary modes to active ones, rather than expecting that we can convince those currently sedentary to take up a sporting activity.

Demands for cyclists to 'protect themselves' by wearing a helmet survive initial scrutiny as rational, but ignore the wider philosophical and public health arguments, which require deeper analysis.

For instance, why should people who use bikes take more responsibility to self-protect, at their own cost and inconvenience? By cycling, users already carry a risk of injury far greater than that of people in a car, but contribute vastly more to society through overall reduced health costs, fewer emissions of noise, local air pollutants and greenhouse gases, and reduced congestion.

Given these huge benefits, CTC believes that policies should reduce the barriers to cycling as much as possible. Forcing users to wear helmets is exactly the sort of unnecessary barrier that may persuade someone to drive, rather than cycle, for a short local journey. Using a mathematical model devised by Australian statistician Prof Piet de Jong, it can be shown that it would only take a tiny reduction in cycle use to result in more lives been lost each year than helmets themselves could possibly save, even if they could magically provide 100% protection against all possible head injuries.

CTC therefore believes that far more effort should go into tackling the deterrents to cycle use (e.g. by improving the planning and design of roads, junctions and cycle facilities, as well as driving standards), with the aim of ensuring that more and safer cycling go hand in hand. Instead, Jersey's legislators have decided to add a deterrent to cycle use, particularly for families.

Tourism to suffer?

In the case of Jersey, there is a further distinct reason why such a law is ill advised. It will severely undermine Jersey's reputation as a tourist destination that welcomes cycling.

Although currently much of Jersey's economy is dependent on its low-tax status as a self-governing island, that position isn't guaranteed in the longer term, and is dependent on the sufferance of its neighbours.

Without its contentious taxation regime, and an enormous financial services sector to support its economy, Jersey would inevitably have to fall back on its traditional resources of agriculture and tourism. The island could - with vastly improved infrastructure - be very well-suited to family cycling holidays. However, again, it is possible that restrictive legislation may drive custom elsewhere, particularly for European travellers such as Germans, Dutch or French, many of whose children do not wear helmets.