A 2006 BMJ study showed that in states which had helmet laws, the amount of cycling to work had reduced by about one third. Other evidence strongly suggests that promotion or compulsion of helmet use deters cycling.Chris Gillham. Bike numbers in Western Australia: government surveys. http://www.cycle-helmets.com/bicycle_numbers.html It has been suggested that this is irrelevant to health as "any cyclist who wants to exercise but hates helmets enough to quit cycling if a law is passed can turn to a multitude of other activities to stay active".Do helmet laws cost society more than they are worth? Bicycle Helmet Safety Institute 2009. http://www.bhsi.org/dejong.htm Accessed 27 February 2011. However, relatively few people who bicycle as part of their daily routine, would increase gym visits or take up other exercise activities if, as a result of a mandatory bicycle helmet law, they were discouraged from cycling. For many people, exercise is only sustainable if it is integrated into daily routine such as shopping errands or traveling to and from work.De Jong, Piet, The Health Impact of Mandatory Bicycle Helmet Laws (February 24, 2010). Available at SSRN: http://ssrn.com/abstract=1368064 Helmet laws seem to offer net health benefit only in dangerous bicycling environments under optimistic assumptions of the efficacy of helmets.
