Study Finds Fatality Rates Increase with Repeal of Helmet Laws

March 31, 2008 - Since 1975, more than 100,000 motorcycle riders in America have died in crashes. 

The majority of states required motorcycle helmets in 1975, but today only 20 states have universal helmet laws that require all riders to wear helmets, 26 states have partial coverage laws (usually only for young riders), and four states have no helmet laws.

A recent study by a University of Missouri professor found that the motorcyclist fatality rate has increased in states that repealed their universal helmet laws during the past decade.

Lilliard Richardson, professor in the MU Truman School of Public Affairs, and David J. Houston, associate professor at the University of Tennessee, Knoxville, compared the changes in helmet laws across all 50 states and the District of Columbia from 1975 through 2004. 

In states where repeals of universal coverage were instituted, the fatality rate increased an average of 12.2 percent.  Conversely, in states with universal helmet laws, the fatality rate was 11.1 percent lower than in states with no helmet mandates.

“Previous studies have been limited to certain states and fail to distinguish the states with partial coverage from those with no legislation,” Richardson said.  “Our focus was not limited to a single state or a single change.  We looked at effects in states that went from universal helmet laws to partial laws and states that went from partial laws to no laws, and states which kept their laws in place.  We highlighted repeals of laws in six states by using separate variables to distinguish the effects of universal and partial coverage.  We included controls for temperature, precipitation, per capita alcohol consumption, income, age, population density and other traffic safety policies.”

Experts have estimated that an additional 615 motorcyclist fatalities occurred in the six states that repealed motorcycle helmet laws from 1997 to 2004, Richardson said.  The researchers also found that fatality numbers in states with partial laws were not statistically different from those with no helmet laws.

“The federal government has pressured states to adopt universal helmet laws, but the trend has been toward more state control of helmet laws,” Richardson said.

“The National Highway Traffic Safety Administration promotes the effectiveness of helmet laws for getting motorcyclists to wear helmets, but there is no strategy for encouraging states to maintain or adopt universal coverage laws.  This does not bode well for the future of universal helmet laws and motorcycle safety in the United States.”

Currently, several states are considering modifying their helmet laws.

“Advocates in many states are pushing to repeal state universal helmet laws or impose partial mandates that require only young riders to wear helmets,” Richardson said.  “Many assume that wearing helmets becomes a habit for riders like wearing a seatbelt is for drivers and that having a law in place isn’t necessary.  This is a misconception.  When laws aren’t in place and enforced, the evidence shows that a majority of riders do not wear helmets.”

The study, “Motorcycle Safety and the Repeal of Universal Helmet Laws,” is available for purchase and was published in the American Journal of Public Health.