Every time they climb aboard a bike, they're 30 times more likely to die in a fatal traffic accident than their counterparts riding inside a car. They have no airbags, no seat belts. Their 600-pound bikes are no match for two-ton cars. No matter who's at fault, they lose every time.
When they ride without a helmet, those risks increase.
In order to qualify for certain federal highway funds, the federal government once required states to have helmet laws on their books. That requirement disappeared in the mid-1970s, and ever since, many states have weakened or repealed their helmet laws.
Last April, Michigan lawmakers repealed a decades-old law that required motorcyclists to wear helmets and replaced it with one that preserved the mandate only for riders under 21.
The result has been more frequent injuries, more severe injuries and more expensive insurance claims, according to a recently released study from the Highway Loss Data Institute.
Claim frequency rose by 10 percent, according to the study, but researchers said the real eye-opener was that claim severity rose 36 percent. Not only are people getting hurt more often, their injuries are more severe.
Prior to the changed law, the average insurance payout on a motorcycle injury claim was $5,410, according to the HLDI study. In the year after the law's repeal, the average increased to $7,257.
"Helmets can't protect against all injuries," said David Zuby, chief researcher of HLDI, "but they do help prevent debilitating and often fatal head trauma."
As part of the law's repeal, Michigan lawmakers included a provision that mandated unhelmeted riders carry $20,000 worth of medical insurance coverage.
Nationally, the number of motorcycle-related deaths have more than doubled in the past 15 years as more and more states drop mandatory helmet laws. One safety expert estimates that wearing a helmet cuts the risk of fatal injuries in half. But many riders feel it is their right to let their hair blow in the wind.
Accidents and deaths increase
Since the law's repeal, the number of motorcycle deaths on Michigan roads has increased. In the first nine months of 2011, while the law remained intact, 99 motorcyclists were killed. In the first nine months of 2012, 120 motorcyclists were killed.
There is not yet a breakdown available on how many of those details were helmeted versus unhelmeted. The jump in deaths also comes amid – helmeted or not – an overall increase in motorcycle accidents on Michigan roads. In 2012, there were 3,509 motorcycle accidents in the state, the highest number in five years.
Proponents of the repeal are quick to note the same causes behind the increase in accidents, namely an improving economy, good weather and more miles ridden, could account for the increase in deaths.
But separate research conducted by Carol Flannagan, a scientist and statistician at the University of Michigan's Transportation Research Institute, concluded that 26 fewer deaths would have occurred had the old law been preserved. The percentage of riders wearing a helmet has dropped from 98 percent to 74 percent since the repeal, according to her analysis.
"We estimate that the effect of the helmet itself, it about cuts the risk of fatality in half," she said.
That jibes with research conducted by the National Highway Traffic Safety Administration, which found that unhelmeted motorists are three times as likely than their helmeted counterparts to suffer a traumatic brain injury in a crash.
More motorcyclists dying
Despite the mounting research that shows helmets help save lives and preserve quality of life, lawmakers have taken the an opposite path. Six states have repealed or scaled back mandatory helmet laws in recent years. Nineteen states, including the District of Columbia, have mandatory laws. Twenty-eight states, like Michigan, have limited laws that typically protect younger riders. Three states have no helmet laws at all. (To see what the laws are in your state, click here.)
The pushback against the laws comes at a time when more motorcyclists than ever are dying, even as American roads are safer than ever.
U.S. traffic fatalities have decreased from 42,013 in 1997 to 32,367 in 2011, a decline of 23 percent. During the same time period, the number of motorcycle fatalities has more than doubled, going from 2,116 in 1997 to 4,612 in 2011.
The number of overall traffic fatalities has decreased in 14 of the past 17 years; the number of motorcycle death has increased in 14 of the past 15 years, according to the Governors Highway Safety Association.
In 2012, the GHSA projects the number of U.S. motorcycle deaths will top 5,000. More dauntingly, the association says that motorcyclists make up 3 percent of traffic, yet represent 14.7 percent of overall traffic fatalities.
Freedom to choose
The statistics don't sway those who favor the repeal. Regardless of risk, they believe helmets are a personal choice.
"I think everybody should have the right to wear them or not, just like seat belts," said Bob Loucks, president of the Mid Michigan Riders motorcycle club. "But I wouldn't go without a helmet."
He said the Mid Michigan Riders have no formal policy on whether their members should wear helmets, but as a matter of practical experience, he cannot remember the last time a unhelmeted rider rode with the group.
"You're vulnerable enough on a motorcycle, and at everybody else's mercy," he said. "The more you can do to protect yourself, the better."
Pete Bigelow is an associate editor at AOL Autos. He can be reached via email at email@example.com and followed @PeterCBigelow.