Traffic safety among motorcyclists in Norway: a study of subgroups and risk factors.

Although it is widely recognized that motorcyclists have a particularly high accident risk, our knowledge of the mechanisms producing this accident risk is incomplete. The aims of the present paper are to identify subgroups of motorcyclists with a particularly high accident risk and to identify the relevant risk factors at work. The study presented in this paper relies both on a questionnaire (N=3356) relating rider characteristics, behaviors and accident risk, and analyses of fatal motorcycle accidents (ca. 100) from 2005 to 2008 in Norway. The results reveal that riders of racing replica bikes (sport bikes), and riders younger than 19 years, including especially youths (16-17 years) riding light motorcycles (≤125 cm(3)), are subgroups of Norwegian motorcyclists with particularly high accident risks. Analysis of fatal motorcycle accidents reveals that about half of the fatal accidents involve sport bikes. Nearly all fatal accidents with sport bikes involved excessive speed. The combination of low age, low experience, risky behavior and "unsafe" attitudes seems to be a particular potent risk factor for Norwegian motorcyclists.