If every state had required all riders to wear helmets from 1976 to 2022, a total of 22,058 motorcyclists’ lives could have been saved. The number represents 11% of all rider fatalities over those years.
“Requiring all riders to wear helmets is a commonsense rule not that different from requiring people in cars to buckle up,” said IIHS President David Harkey. “We have an obligation to protect everyone on our roadways through smart policy.”
Currently, only 17 states and the District of Columbia have all-rider helmet laws in place. Meanwhile record numbers of motorcyclists — more than 6,000 each year — were killed in 2021 and 2022, the most recent years for which statistics are available. If the remaining states came on board, the death toll could be cut by as much as 10%. Other measures like crash prevention technology that’s better at detecting motorcycles and mandatory antilock brakes on motorcycles themselves are also needed to improve rider safety. But all-rider helmet laws are a key part of a Safe System approach to the issue.
“Wearing a helmet is one of the biggest things riders can do to protect themselves from death and traumatic brain injury,” said Eric Teoh, IIHS director of statistical services and the author of the paper. “We understand that requiring helmets for all riders everywhere would be unpopular with some motorcyclists, but this could save hundreds of lives each year. Those aren’t just numbers. They’re friends, parents and children.”
The first all-rider helmet laws took effect in 1967, after the National Highway Safety Act made them a prerequisite for certain highway safety and construction funds. By July 1975, 47 states and the District of Columbia had such laws on the books.
In the years since the funding restriction was removed in 1976, however, most states have weakened their helmet laws to be applicable only to riders under 18 or 21 years old or repealed them altogether. This trend has persisted even as seat belt laws have become more stringent.
To determine the human cost of allowing unhelmeted motorcycling, Teoh compared the number of helmeted and unhelmeted riders killed each year in jurisdictions with and without all-rider helmet laws. That allowed him to estimate helmet use rates for the states when all-rider laws were in effect and when they weren’t. He then estimated the number of lives that would have been saved each year if all-rider helmet laws had been universal throughout the entire 1976-2022 period. For that calculation, he used the 37% decrease in motorcyclist fatality risk associated with wearing a helmet established by other published research. In another analysis, he estimated the cumulative effect of allowing unhelmeted motorcycling within each state.
Notably, population-level helmet use has increased over time in jurisdictions with and without all-rider helmet laws. However, helmet use rates in states with all-rider laws were generally 2-3 times as high as in states without them over the study period. Teoh’s estimates take those historical changes and differing helmet use rates into account.
The number of lives lost as the result of laws that allow unhelmeted riding ranged from 182 in 1976 to 673 in 2021. Most states had all-rider laws in 1976, but compliance was spotty. Helmet use was higher in 2021, but far fewer jurisdictions required them.
By state, the largest number of lives lost — 2,536 — was in California, primarily due to its large population and long riding season. Further excess deaths have been averted in that state since 1992, when an all-rider helmet law went into effect there. Other states with high numbers of additional deaths such as Texas (2,490), Florida (1,786), Illinois (1,738), Ohio (1,651), Indiana (1,151) and South Carolina (1,000) still allow unhelmeted riding, so the toll in those places will continue to rise.
“Requiring every rider to wear a helmet is a simple change that could have a dramatic and immediate effect on fatality rates,” Harkey said. “With 6,000 riders dying every year, it’s unconscionable that we haven’t already made these laws universal.”