The role of sales of new motorcycles in a recent increase in motorcycle mortality rates

INTRODUCTION: The National Highway Traffic Safety Administration (NHTSA) has reported that mortality rates from crashes among motorcycle riders in the United States increased from 21.0 per 100 million motorcycle miles traveled in 1997 to 38.4 per 100 million motorcycle miles traveled in 2003. At the same time, annual domestic sales of new, on-road motorcycles increased from 247,000 in 1997 to 648,000 in 2003. METHOD: This study used data from the NHTSA Fatality Analysis Reporting System and annual sales figures for on-road motorcycles to determine if newer motorcycles were more likely to be involved in fatal crashes and if fatal crashes involving newer motorcycles could account for the mortality increase after 1997. RESULTS: Mortality rates were 7.9, 8.1, 5.4, and 2.9 per 10,000 motorcycles sold for motorcycles <1, 1-3, 4-6, and 7-11 years old, respectively, from 1994 to 2003. Assuming complete registration, the number of motorcycles sold during the 2000-2003 time period accounted for 42.4% of the total number of motorcycles registered in 2003. Motorcycles sold during 2000-2003 were associated with 52.5% of all motorcycle deaths in 2003. The increase in the number of deaths associated with motorcycles less than four years old between 1997 and 2003 accounted for 78.1% of the total increase in motorcyclist deaths over this time period. CONCLUSIONS: Two possible explanations for the association between high sales volumes and mortality rates are: (a) increased exposure from more extensive use of motorcycles when they are new; and (b) inexperience with motorcycle riding or with specific motorcycles. IMPACT ON INDUSTRY: This study suggests that the deaths of growing numbers of motorcyclists are a consequence of the financial success of the motorcycle industry.