Exposure survey of motorcyclists in New South Wales.

This paper reports the results of an exposure survey of 794 registered motorcycle riders, with an average of 18.1 years of riding experience, in the State of New South Wales, Australia. Respondents completed two postal surveys, separated by about 6 months, that included items relating to their crash history, riding patterns, characteristics of their motorcycle, and its odometer reading. Odometer readings indicated that respondents rode a mean of 5208 km each year, and that annual exposure was related to gender, motorcycle type, and dominant riding location, time of week, and purpose. The amount of riding reported for different purposes changed with age, with older riders more likely than younger riders to ride for recreational reasons and on weekends. The mean crash rate (based on self-reported crash involvement) was 0.96 crashes/100,000 km. The crash rate declined with age, was highest in the Sydney metropolitan area, was lowest for motorcycles with large engines, and was highest for trail and dual-use motorcycles. There was a relationship between annual exposure and crash risk such that riders who rode relatively little had higher crash risks (per 100,000 km travelled) than riders who rode more often. A cluster analysis identified three groups of riders with higher-than-average risks of crash involvement.