ScienceWeek

PUBLIC HEALTH: ON US MOTORCYCLE FATALITIES

The following points are made by L.J. Paulozzi and R. Patel (Morb. Mort. Wkly. Rep. 2004 53:1103):

1) Motorcycles are the most dangerous type of motor vehicle to drive.[1] These vehicles are involved in fatal crashes at a rate of 35.0 per 100 million miles of travel, compared with a rate of 1.7 per 100 million miles of travel for passenger cars. The National Highway Traffic Safety Administration (NHTSA) has reported increasing numbers of motorcycle deaths associated with alcohol-impaired driving in recent years, especially among persons aged => 40 years.[2] To determine trends by age group in motorcycle fatalities overall and in those involving alcohol impairment, CDC analyzed data from the NHTSA Fatality Analysis Reporting System (FARS) for 1983, 1993, and 2003.

2) The analysis indicated that during 1983-2003 the overall prevalence of elevated blood alcohol concentrations (BACs) among motorcycle drivers who died in crashes declined; however, the peak rate of death among alcohol-impaired motorcycle drivers shifted from those aged 20-24 years to those aged 40-44 years. Strong enforcement of existing BAC laws, together with other public health interventions aimed at motorcyclists, might reduce the crash mortality rate, especially among older drivers.

3) Overall, motorcycle mortality rates per 100,000 population declined from 1.6 in 1983 to 0.9 in 1993 and then increased to 1.2 in 2003. Most of the decline occurred among motorcyclists aged less than 30 years. For example, among drivers aged 20-24 years, the mortality rate declined from 5.0 in 1983 to 3.0 in 1993 and 2.4 in 2003, whereas among drivers aged 40-44 years, the mortality rate declined from 1.2 in 1983 to 1.0 in 1993 and then increased to 1.9 in 2003. Among alcohol-impaired motorcycle drivers, the mortality rate was highest among persons aged 20-24 years in 1983 and among persons aged 40-44 years in 2003. In 1983, 8.2% of alcohol-impaired, fatally injured motorcycle drivers were aged 40 years; by 2003, 48.2% of such drivers were in this age group.

4) During 1983-2003, the overall proportion of both motorcycle and passenger-car drivers dying in crashes who were alcohol impaired declined. Alcohol impairment occurred less often in automobile drivers of all ages in 2003 compared with 1983. This decrease also was observed among motorcycle drivers, except for persons aged 55-59 years, for whom the proportion with alcohol impairment increased from 16.7% in 1983 to 21.1% in 2003. In 2003, the proportion of fatally injured drivers with alcohol impairment was consistently lower among motorcycle drivers than among passenger-car drivers at each age through age 34 years. After age 34 years, however, higher proportions of motorcycle drivers than passenger-car drivers were alcohol-impaired.

5) Sales of new on-road motorcycles increased substantially from 1997 through 2003, from 247,000 to 648,000 units.[5] This increase coincided with a 69.8% increase in the number of motorcyclist traffic fatalities during that period, from 2,116 in 1997 to 3,592 in 2003. The increased number of motorcycles on the road probably contributed to the increase in the motorcycle mortality rate during 1993-2003. The mortality rate increase has been restricted to older motorcycle drivers.[2-4]

References (abridged):

1. National Highway Traffic Safety Administration. Traffic safety facts 2002. Washington, DC: US Department of Transportation, National Highway Traffic Safety Administration, National Center for Statistics and Analysis; 2004. Publication no. DOT-HS-809-620

2. Shankar UG. Research note: alcohol involvement in fatal motorcycle crashes. Washington, DC: US Department of Transportation, National Highway Traffic Safety Administration, National Center for Statistics and Analysis; 2003. Publication no. DOT-HS-809-576

3. Hedlund J, Ulmer R, Northrup V. State laws and practices for BAC testing and reporting drivers involved in fatal crashes. Washington, DC: US Department of Transportation, National Highway Traffic Safety Administration; 2004. Publication no. DOT-HS-809-756

4. US Census Bureau. U.S. resident population estimates, 1983, 1993, 2003. Available at http://eire.census.gov/popest

5. Motorcycle Industry Council. 2003 motorcycle statistical annual, Motorcycle Industry Council. Irvine, CA: Motorcycle Industry Council; 2004

Centers for Disease Control and Prevention http://www.cdc.gov

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Related Material:

ON AUTOMOBILE TRAFFIC CRASHES

The following points are made by Leonard Evans (American Scientist 2002 90:244):

1) The focus on vehicle factors factors over which they have no control has encouraged American drivers to regard safety as something out of their control. The American focus on airbags is one example of this. These were mandated by a lawyer-led safety agency that claimed safety benefits far in excess of published technical estimates and ignored technical information documenting their harmful effects. Before a drug can be prescribed in the United States, it must meet two basic standards efficacy and safety. Airbags were not shown to meet either, but they were not merely offered to the public, their installation was required. Now, the US is the only country in the world in which it is illegal to purchase a new car without a device that is known to increase the net harm to women (Dalmotas et al. 1996) and to increase fatality risk in children (Glass et al. 2000). The focus on airbags contributed to postponing mandatory belt-wearing laws, a delay that produced thousands of additional deaths. More fundamentally, the focus on airbags helped mislead U.S. road users into the belief that safety would be achieved without action on their part.

2) This focus lingers on in the futile pursuit of a safe or smart airbag and the misplaced attention given to this pursuit. After a crash has already commenced, there is so little time for an airbag to inflate that it must inflate at a speed high enough to injure anyone who happens to be in the deployment space. Making airbags less violent will reduce the injuries they cause but will subtract from their already modest net contribution to safety. Effective occupant protection requires that the occupant be restrained before the crash commences.

3) Nations with safer records than the United States have stricter alcohol laws, which they enforce more stringently; higher belt-wearing rates; and many driver-focused policies. As one example of the difference in attitudes, the US has an active market in radar detectors whose only purpose is to facilitate illegal speeding, a device that is prohibited in other countries.

References (abridged):

1. Aldman, B. 1974. Possible effects of air bag inflation on a standing child. Proceedings of the 18th Annual Conference of the American Association for Automotive Medicine.

2. Dalmotas, D. ]., ]. Hurley, A. German and K. Digges. 1996. Air bag deployment crashes in Canada. Paper 96-S10-05,15th Enhanced Safety of Vehicles Conference, Melbourne, Australia, 13-17 May.

3. Ernst, E., E. Bruhning, K. P. Glaeser and M. Schmidt. 1991. Compatibility problems of small and large passenger cars in head on collisions. Paper presented to the 13th International Technical Conference on Experimental Safety Vehicles, Paris, 4-11 November.

4. Evans, L. 1991. Traffic Safety and the Driver. New York: Van Nostrand Reinhold.

5. Evans, L. 1993. Medical accidents: No such thing? British Medical Journal 307:1438-1439.

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