In 1997, Texas repealed its mandatory helmet law, making helmet use optional for all motorcycle riders aged 21 or older. This study, led by Al Bavon, Ph.D., and Christina Standerfer, Ph.D., of the University of Arkansas Clinton School of Public Service, analyzed data on motorcycle fatalities from 1994 to 2004 to examine trends in the rate of fatal injuries before and after the change in helmet laws.
Overall, the number of motorcycle deaths increased by 30 percent after the repeal of the helmet law. While this was partly explained by an increase in motorcycle ridership, other measures of motorcycle fatalities increased as well. The number of deaths per 100,000 registered motorcycles increased from 89 in 1994 to 101 in 2004 – a 15 percent increase. Motorcycle fatalities per vehicle mile traveled also increased significantly, by 25 percent.
"Since the 1997 repeal of the mandatory helmet law in Texas substantially fewer motorcyclists choose to wear protective helmets and substantially more fatal injuries occur per motorcycles registered in the state," the study concluded.
A month-by-month breakdown showed a "sudden upward trend" in motorcycle fatalities in September 1997 – the same month the helmet laws changed. This suggests "a strong correlation between the enactment of the repeal legislation and the increase in fatalities," Bavon and Standerfer wrote.
Texas is among the 30 states that have no mandatory (or minimally restrictive) helmet laws for motorcyclists over age 21. Research consistently has shown that wearing a helmet reduces the risk of head injuries and deaths among motorcyclists. The repeal of the Texas legislation provides an opportunity to examine motorcycle fatality rates before and after a change in helmet laws.
As in previous studies, the absence of motorcycle helmet laws is linked to more motorcycle deaths not only overall, but also in terms of number of motorcycles on the road and total number of miles traveled. Bavon and Standerfer highlighted the correlation between increased motorcycle registrations and increased fatalities.
"This suggests that the combination of increased exposure with the option not to wear a helmet has the potential to have dramatic detrimental effects on the number of fatal injuries to motorcyclists," they wrote.
Even in the face of mounting evidence that helmet laws reduce fatalities, the trend in many states appears to be moving away from universal helmet laws, according to an editorial by David J. Houston, Ph.D., of the University of Tennessee.
"From a public health perspective, the case for universal motorcycle helmet laws is strong although in many states the political will to adopt these laws is weak,” he wrote.
The Southern Medical Journal is the official journal of the Southern Medical Association.