ARLINGTON, Va. — The average insurance payment on a motorcycle injury claim rose substantially in Michigan after the state changed its helmet law to exempt most riders last year, a new analysis by the Highway Loss Data Institute (HLDI) finds. The result is consistent with previous studies that show that rescinding helmet requirements results in more fatalities and hospital admissions.
For more than 40 years, Michigan required all motorcycle riders to wear helmets. However, as of April 12, 2012, the requirement applies only to riders younger than 21. All others may opt to ride without a helmet if they have either passed a motorcycle safety course or have held the motorcycle endorsement on their driver's license for at least two years. Unhelmeted riders also must carry at least $20,000 in medical coverage.
The National Highway Traffic Safety Administration (NHTSA) estimates that helmets cut the risk of a motorcycle fatality by 37 percent, and safety groups predicted that deaths would increase in Michigan as a result of the change.
The insurance loss trends reported by HLDI confirm that motorcyclists' injuries in the state have indeed become more serious. To see how the law change affected injuries, HLDI analysts compared medical payment (MedPay) losses from the 2010-11 riding seasons with the 2012 season. MedPay coverage insures against injuries sustained by motorcycle operators. Since many motorcyclists put their bikes away for the winter in northern states, only data from May through September were included in the study.
HLDI measures insurance losses three ways: by claim frequency, or rate; claim severity, or the average amount paid on each claim; and overall losses, which is the product of frequency and severity. Comparing losses in Michigan with losses in Illinois, Indiana, Ohio and Wisconsin — where helmet laws did not change — and controlling for motorcycle age and class; rider age, gender and marital status; weather; and other factors, HLDI found that MedPay claim frequency was 10 percent higher than would have been expected without the law change, claim severity was 36 percent higher, and overall losses were 51 percent higher. The increases in claim severity and overall losses were statistically significant, but the change in claim frequency was not.
Further calculations were done to account for changes in policy limits that resulted from the law change. The HLDI analysts knew that the law's new requirement that helmetless riders carry at least $20,000 of MedPay coverage would affect claim severity and overall losses if riders who previously carried less coverage increased their insurance limits. That's because policies with higher limits will pay more for serious injuries than those with lower limits. To see how much of the change in severity was a result of riders going without helmets as opposed to such coverage changes, they controlled for policy limits, finding that claim severity still increased 22 percent after the new law went into effect.
How Michigan medical payment losses changed after the state
weakened its helmet law versus control states
"Weakening the helmet law seems to have made it somewhat more likely that riders will sustain injuries, but the big impact has been on the seriousness of the injuries," says David Zuby, chief research officer of HLDI and the Insurance Institute for Highway Safety. "Helmets can't protect against all injuries, but they do help prevent debilitating and often fatal head trauma."
Opponents of helmets sometimes argue that they make crashes more likely by increasing fatigue and impeding visibility and hearing. By that logic, the crash rate should decline when a helmet requirement is repealed. However, HLDI analysts found that claim frequency under collision insurance, which covers crash damage to a motorcycle and is the coverage most likely to come into play after any crash, rose 12 percent. (Collision claim severity remained unchanged.) The fact that the claim rate didn't fall once helmets were no longer mandatory undercuts this particular argument.
It's not clear what would cause collision frequency to rise, but it's possible that riders who prefer not to wear helmets rode more miles after the law change. That also could explain the 10 percent increase in MedPay claim frequency.
"More riding might account for more frequent crashes, but it doesn't explain the increase in severity," says HLDI Vice President Matt Moore. "Motorcyclists are sustaining more injuries per crash or more serious ones after the law change than before."
HLDI data don't include information on where a crash occurred, so in this analysis, Michigan crashes are crashes of motorcycles insured and garaged in the state. Likewise, the control-state crashes are only crashes of motorcycles insured and garaged in those states. There also is no way to know how many of the claims involved unhelmeted motorcyclists.
Michigan is one of 28 states that currently have helmet laws covering only some riders, usually those under 18. Illinois, Iowa and New Hampshire have no helmet requirements. Only 19 states and the District of Columbia require helmets for all motorcyclists.