Motorcycle helmet usage

Kraus, J. F., C. Peek, D. L. McArthur and A. Williams (1994). The effect of the 1992 California motorcycle helmet usage law on motorcycle crash fatalities and injuries. 272,1506-1511. 

Quasi-experimental evaluation of the introduction of universal helmet laws. Mandatory helmet laws have been a very effective means of increasing helmet usage and rider safety. The most effective laws are known as xmiversal helmet laws. These laws require that all motorcycle riders at all times wear a helmet, without any exceptions. In contrast to these laws are limited (or state) helmet laws, which are often the resulting compromise between safety advocates and motorcycle riders lobbyists. These laws require helmet use only for specific sub-groups such as riders under a certain age, riders in the learning phase, and riders with less than a year of experience. Whenever they are compared, the limited helmet laws are less effective in reducing deaths and injuries than the universal helmet laws (Ichikawa et al., 2003 Sosin and Sacks,... 

O Connor, P. J. (2005). Motorcycle Helmets and Spinal Cord Injury Helmet Usage and... 

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