Q&A: Motorcycles — helmets

March 2013

1 Why is it important for motorcyclists to wear helmets?

Compared with cars, motorcycles are an especially dangerous form of travel. The National Highway Traffic Safety Administration (NHTSA) estimates that per mile traveled, the number of deaths on motorcycles in 2010 was about 30 times the number in cars. National Highway Traffic Safety Administration. 2012. Traffic safety facts, 2010: motorcycles. Report no. DOT HS-811-639. Washington, DC: U.S. Department of Transportation.  Motorcycles often have excessive performance capabilities, including especially rapid acceleration and high top speeds. They are less stable than cars in emergency braking and less visible to other motorists. Motorcyclists are more prone to crash injuries than car occupants because motorcycles are unenclosed, leaving riders vulnerable to contact with hard road surfaces, other vehicles and fixed objects such as trees. This is why wearing a helmet, as well as other protective clothing, is so important. 

2 How effective are helmets?

Helmets decrease the severity of head injuries, the likelihood of death and the cost of medical care. Helmets are highly effective in preventing brain injuries, which often require extensive treatment and may result in lifelong disability. NHTSA estimates that in the event of a crash, unhelmeted motorcyclists are 3 times more likely than helmeted riders to suffer traumatic brain injuries, and that motorcycle helmets reduce the likelihood of a crash fatality by 37 percent. National Highway Traffic Safety Administration. 2008. Traffic safety facts, laws: motorcycle helmet use laws. Report no. DOT HS-810-887W Washington, DC: U.S. Department of Transportation.  Norvell and Cummings found a 39 percent reduction in the risk of death after adjusting for the effects of rider age, gender and seat position. Norvell, D.C. and Cummings, P. 2002. Association of helmet use with death in motorcycle crashes: a matched-pair cohort study.American Journal of Epidemiology 156(5):483-7.   A recent literature review estimated that helmets reduce the risk of death in a crash by 42 percent and the risk of head injuries by 69 percent. Liu, B.C; Ivers, R.; Norton, R.; Boufous, S.; Blows, S.; and Lo, S.K. 2009. Helmets for preventing injury in motorcycle riders (Review), Cochrane Database of Systematic Reviews 2009, Issue 1. Oxfordshire, England: The Cochrane Collaboration.  

3 Are some helmets more effective than others?

No real-world crash studies have evaluated the effectiveness of helmets that do not meet federal performance standards for preventing injury or death, often referred to as novelty helmets. NHTSA laboratory tests suggest that head injuries are much more likely with these helmets than with ones certified to the NHTSA standard. National Highway Traffic Safety Administration. 2007. Summary of novelty helmet performance testing. Traffic safety facts, Research note. Report no. DOT HS-810-752. Washington, DC: U.S. Department of Transportation.

Helmets are available in different styles, including half-coverage, open-face and full-face. A recent study evaluated the effectiveness of these different styles and found that crash-involved riders wearing half-coverage helmets were twice as likely to suffer traumatic brain injuries than riders wearing open-face or full-face helmets. Yu, W.; Chen, C.; Chiu, W.; and Lin, M. 2011. Effectiveness of different types of motorcycle helmets and effects of their improper use on head injuries. International Journal of Epidemiology 40(3):794-803.

4 Are there drawbacks to helmet use?

Claims have been made that helmets increase the risk of neck injury and reduce peripheral vision and hearing, but there is no credible evidence to support these arguments. A study by J.P. Goldstein often is cited by helmet opponents as evidence that helmets cause neck injuries, allegedly by adding to head mass in a crash. Goldstein, J.P. 1986. The effect of motorcycle helmet use on the probability of fatality and the severity of head and neck injuries: a latent variable framework. Evaluation Review 10(3):355-75.  More than a dozen studies have refuted Goldstein's findings. A 1994 study analyzed 1,153 motorcycle crashes in four Midwestern states and determined that "helmets reduce head injuries without an increased occurrence of spinal injuries in motorcycle trauma." Orsay, E.M.; Muelleman, R.L.; Peterson, T.D.; Jurisic, D.H.; Kosasih, J.B.; and Levy, P. 1994. Motorcycle helmets and spinal injuries: dispelling the myth. Annals of Emergency Medicine 23(4):802-6.  More recently, a review of cases in the National Trauma Data Bank found that helmeted riders were less likely to have cervical spine fractures in crashes than unhelmeted riders. Crompton, J.G.; Bone, C.; Oyetunji, T.; Pollack, K.M.; Bolorunduro, O.; Villegas, C.; Stevens, K.; Cornwell, E.E. 3rd.; Efron, D.T.; Haut, E.R.; and Haider, A.H.  2011.  Motorcycle helmets associated with lower risk of cervical spine injury: debunking the myth.  Journal of the American College of Surgeons 212(3):295-300. 

Regarding claims that helmets obstruct vision, studies show full-coverage helmets provide only minor restrictions in horizontal peripheral vision. A 1994 study found that wearing helmets does not restrict the ability to hear horn signals or to see a vehicle in an adjacent lane prior to initiating a lane change. McKnight, A.J. and McKnight, A.S. 1994. The effects of motorcycle helmets upon seeing and hearing. Report no. DOT HS-808-399. Washington, DC: National Highway Traffic Safety Administration.  To compensate for any restrictions in lateral vision, riders increased their head rotation prior to a lane change. There were no differences in hearing thresholds under three helmet conditions: no helmet, partial coverage, and full coverage. The noise typically generated by a motorcycle is so loud that any reduction in hearing capability that may result from wearing a helmet is inconsequential. Sound loud enough to be heard above the engine can be heard when wearing a helmet.

5 What is the history of helmet use laws in the United States?

In 1967, the federal government began requiring states to enact motorcycle helmet use laws to qualify for certain federal safety and highway construction funds. By the end of 1969, 39 states had universal helmet laws. By 1975, all but three states mandated helmets for all motorcyclists.

As the U.S. Department of Transportation moved in 1976 to assess financial penalties on states without helmet laws, Congress responded to state pressure by revoking federal authority to assess penalties for noncompliance. Between 1976 and 1978, 20 states weakened their helmet use laws to apply only to young riders, usually those younger than 18. Eight states repealed helmet use requirements for all motorcyclists.

In the 1980s and early 1990s, several states reinstated helmet laws applying to all riders. In the 1991 Intermodal Surface Transportation Efficiency Act, Congress created incentives for states to enact helmet use and safety belt use laws. States with both laws were eligible for special safety grants, but states that had not enacted them by October 1993 had up to 3 percent of their federal highway allotment redirected to highway safety programs.

Four years after establishing the incentives, Congress again reversed itself. In the fall of 1995, Congress lifted federal sanctions against states without helmet use laws, paving the way for state legislatures to repeal helmet laws. Now only 19 states and the District of Columbia helmet laws covering all riders, and 28 states have laws covering some riders, usually people younger than 18. Three states (Illinois, Iowa, and New Hampshire) do not have any helmet requirements.

6 How do helmet laws affect helmet use?

Helmet use approaches 100 percent when all motorcyclists are required to wear helmets, compared with about 50 percent when there is no helmet law or a law applying only to some riders. National Highway Traffic Safety Administration. 2005. Without motorcycle helmets, we all pay the price. Washington, DC: U.S. Department of Transportation. Ulmer, R.G. and Northrup, V.S. 2005. Evaluation of the repeal of the all-rider motorcycle helmet law in Florida. Report no. DOT HS-809-849. Washington, DC: National Highway Traffic Safety Administration.  In 2011, 96 percent of motorcyclists observed in states with universal helmet laws were wearing helmets. In states without such laws, helmet use was 55 percent. Use of helmets judged to be compliant with federal safety regulations was 84 percent among motorcyclists in states with universal helmet laws and 50 percent in states without such laws. National Highway Traffic Safety Administration. 2012. Motorcycle helmet use in 2011 — overall results. Report no. DOT HS-811-610. Washington, DC: U.S. Department of Transportation.

Among recently surveyed motorcyclists, 22 percent of those who said they believe helmets keep riders safer reported not always wearing helmets while riding. McCartt, A.T.; Blanar, L.; Teoh, E.R.; and Strouse, L.M. 2011. Overview of motorcycling in the United States: a national telephone survey. Journal of Safety Research 42(3):177-194.  However, only 6 percent of motorcyclists in states with universal laws reported not always wearing helmets, suggesting that education alone would not be as beneficial in increasing helmet use as a universal helmet law.

7 How do helmet laws affect deaths and injuries?

In states that either reinstated or enacted universal motorcycle helmet laws, deaths and injuries of motorcyclists decreased. In states that repealed or weakened their universal helmet laws, deaths and injuries rose.

Some examples of helmet laws and their effect on helmet use and death and injury rates:

• When California's helmet use law covering all riders took effect on January 1, 1992 helmet use jumped to 99 percent from about 50 percent before the law, Kraus, J.F.; Peek, C.; and Williams, A.F. 1995. Compliance with the 1992 California motorcycle helmet use law. American Journal of Public Health 85(1):96-9.  and the number of motorcyclist fatalities decreased 37 percent. Kraus, J.F.; Peek, C.; McArthur, D.L.; and Williams, A.F. 1994. The effect of the 1992 California motorcycle helmet usage law on motorcycle crash fatalities and injuries. Journal of the American Medical Association 272(19):1506-11.
• Nebraska reinstated a helmet law on January 1, 1989, after repealing an earlier law in 1977. The state then saw a 22 percent reduction in serious head injuries among motorcyclists. Muelleman, R.L.; Mlinek, E.J.; and Collicott, P.E. 1992. Motorcycle crash injuries and costs: effect of a re-enacted comprehensive helmet use law. American Journal of Emergency Medicine 21(3):266-72.
• From 1968 to 1977, Texas had a universal helmet use law estimated to have saved 650 lives, but the law was amended in 1977 to apply only to riders younger than 18. The weakened law coincided with a 35 percent increase in motorcyclist fatalities. Texas reinstated its helmet law for all motorcyclists in September 1989. The month before the law took effect, the helmet use rate was 41 percent. The rate jumped to 90 percent during the first month of the law and rose to 98 percent by June 1990. Lund, A.K.; Williams, A.F.; and Womack, K.N. 1991. Motorcycle helmet use in Texas. Public Health Reports 106(5):576-8.  Serious injury crashes per registered motorcycle decreased 11 percent. Mounce, N.; Brackett, Q.; Hinshaw, W.; Lund, A.K.; and Wells, J.K. 1992. The reinstated comprehensive motorcycle helmet law in Texas. Arlington, VA: Insurance Institute for Highway Safety.  But in September 1997, Texas again weakened its helmet law, requiring helmets only for riders younger than 21. Helmet use in Texas dropped to 66 percent by May 1998, and operator fatalities increased 31 percent in the first full year following the repeal. Preusser, D.F.; Hedlund, J.H.; and Ulmer, R.G. 2000. Evaluation of motorcycle helmet law repeal in Arkansas and Texas. Washington, DC: National Highway Traffic Safety Administration.
• Kentucky repealed its universal helmet law in 1998, followed by Louisiana in 1999. These actions resulted in lower helmet use, and quickly increased motorcyclist deaths in these states by 50 percent and 100 percent, respectively. Ulmer, R.G. and Preusser, D.F. 2003. Evaluation of the repeal of motorcycle helmet laws in Kentucky and Louisiana. Report no. DOT HS-809-530. Washington, DC: National Highway Traffic Safety Administration.
• In 2000, Florida's universal helmet law was weakened to exempt riders 21 and older who have at least $10,000 of medical insurance coverage. An Institute study found that the motorcyclist death rate in Florida increased by about 25 percent after the state weakened its helmet law. Kyrychenko, S.Y. and McCartt, A.T. 2006. Florida weakened motorcycle helmet law: effects on death rates in motorcycle crashes.Traffic Injury Prevention 7(1):55-60.  The death rate rose from 31 fatalities per 1,000 crash involvements before the law change (1998-99) to 39 fatalities per 1,000 crash involvements after (2001-2002). An estimated 117 deaths could have been prevented during 2001-02 if the law had not been changed.  A study of the Florida law found a similar effect; motorcyclist deaths per 10,000 motorcycle registrations increased 21 percent during the two years after the law was changed compared with the two years before. Ulmer, R.G. and Northrup, V.S. 2005. Evaluation of the repeal of the all-rider motorcycle helmet law in Florida. Report no. DOT HS-809-849. Washington, DC: National Highway Traffic Safety Administration.

In two studies, researchers modeled state motorcyclist fatality rates by helmet law type, after controlling for factors such as per capita income, population density and annual precipitation amounts. Houston, D.J. and Richardson, Jr., L.E. 2007. Motorcycle safety and the repeal of universal helmet laws. American Journal of Public Health 97(11):2063-9. Houston, D.J. and Richardson, Jr., L.E. 2008. Motorcyclist fatality rates and mandatory helmet-use laws. Accident Analysis and Prevention 40(1):200-8.  Death rates were lowest in states with helmet laws that cover all riders. Rates in states with helmet laws that cover only some riders were lower than those in states with no helmet law, but not as low as rates in states with helmet laws that cover all riders. These results held for all three types of rates considered: deaths per 10,000 registered motorcycles, deaths per 100,000 population and deaths per 10 billion vehicle miles traveled. 

8 Are there other benefits of helmet use laws?

Helmet use laws may lead to a decline in motorcycle thefts, possibly because some potential thieves do not have helmets, and not wearing a helmet would attract police notice. After Texas enacted its universal helmet law, motorcycle thefts in 19 Texas cities decreased 44 percent between 1988 and 1990, according to the Texas Department of Public Safety. Motorcycle thefts dropped dramatically in three European countries after the introduction of laws that fined motorcyclists for failure to wear helmets. Mayhew, P.; Clarke, R.V.; and Elliott, D. 1989. Motorcycle theft, helmet legislation, and displacement. The Howard Journal 28(1):1-8.  

9 How do helmet use laws impact health care costs?

Unhelmeted riders have higher health care costs as a result of their crash injuries and many lack health insurance. A 2002 review of 25 studies of the costs of injuries from motorcycle crashes reported that helmet use reduced the cost of medical treatment, length of hospital stay and probability of long-term disability for riders injured in a crash. Lawrence, B.A.; Max, W.; and Miller, T.R. 2002. Cost of injuries resulting from motorcycle crashes: a literature review. Report no. DOT HS-809-242. Washington, DC: National Highway Traffic Safety Administration.   Studies that looked at who pays for injured riders’ medical care found that just over half of injured riders have private health insurance coverage. For those without private insurance, most of the medical costs are paid by the government. A more recent study confirmed the earlier findings that unhelmeted riders had much higher hospital chrages than helmeted ones. Heldt, K.A.; Renner, C.H.; Boarini, D.J.; and Swegle, J.R.  2012. Costs associated with helmet use in motorcycle crashes: the cost of not wearing a helmet.  Traffic Injury Prevention 13(2):144-9. 

Here are a few examples of how states' helmet law changes affected health care costs:

• After California introduced a universal helmet use law in 1992, health care costs associated with head-injured motorcyclists declined. Max, W.; Stark, B.; and Root, S. 1998. Putting a lid on injury costs: the economic impact of the California motorcycle helmet law.Journal of Trauma 45(3):550-6.  The rate of motorcyclists hospitalized for head injuries decreased by 48 percent in 1993 compared with 1991, and total costs for patients with head injuries decreased by $20.5 million during this period. 
• When Nebraska reinstated its universal helmet use law, acute medical hospital charges for injured motorcyclists declined 38 percent. Muelleman, R.L.; Mlinek, E.J.; and Collicott, P.E. 1992. Motorcycle crash injuries and costs: effect of a re-enacted comprehensive helmet use law. American Journal of Emergency Medicine 21(3):266-72.

• When Florida weakened its universal helmet law in 2000 to exclude riders 21 and older who have at least $10,000 of medical insurance coverage, hospital admissions of motorcyclists with head injuries increased 82 percent during the 30 months following the law change. Ulmer, R.G. and Northrup, V.S. 2005. Evaluation of the repeal of the all-rider motorcycle helmet law in Florida. Report no. DOT HS-809-849. Washington, DC: National Highway Traffic Safety Administration.  The average inflation-adjusted cost of treating these injuries went up from about $34,500 before the helmet law was weakened to nearly $40,000 after — four times as high as the $10,000 minimum medical insurance requirement. 
• Studies conducted in Nebraska, Washington, California and Massachusetts illustrate the burden that injured motorcyclists place on taxpayers. Forty-one percent of motorcyclists injured in Nebraska from January 1988 to January 1990 lacked health insurance or received Medicaid or Medicare. Muelleman, R.L.; Mlinek, E.J.; and Collicott, P.E. 1992. Motorcycle crash injuries and costs: effect of a re-enacted comprehensive helmet use law. American Journal of Emergency Medicine 21(3):266-72.  In Seattle, 63 percent of trauma care for injured motorcyclists in 1985 was paid by public funds. Rivara, F.P.; Dicker, B.G.; Bergman, A.B.; Dacey, R.; and Herman, C. 1988. The public cost of motorcycle trauma. Journal of the American Medical Association 260(2):221-3.  In Sacramento, public funds paid 82 percent of the costs to treat orthopedic injuries sustained by motorcyclists during 1980-83. Bray, T.; Szabo, R.; Timmerman, L.; Yen, L.; and Madison, M. 1985. Cost of orthopedic injuries sustained in motorcycle accidents.Journal of the American Medical Association 254(17):2452-3.  Forty-six percent of motorcyclists treated at Massachusetts General Hospital during 1982-83 were uninsured. Bray, T.; Szabo, R.; Timmerman, L.; Yen, L.; and Madison, M. 1985. Cost of orthopedic injuries sustained in motorcycle accidents.Journal of the American Medical Association 254(17):2452-3.

10 Are helmet use laws that apply only to young motorcyclists effective?

No. Helmet use laws that apply only to young riders are virtually impossible to enforce. Helmet use for all riders is low in states where partial laws are in effect, and death rates are 20 to 40 percent lower in states with universal laws than in those with weak laws or no laws. U.S. General Accounting Office. 1991. Highway safety: motorcycle helmet laws save lives and reduce costs to society. Washington, DC.

In 2000, Florida weakened its helmet law to exclude riders 21 and older with at least $10,000 of medical insurance coverage. Even though riders younger than 21 still were required to wear helmets, an Institute study found that they were 97 percent more likely to die in crashes after the law change than before. Kyrychenko, S.Y. and McCartt, A.T. 2006. Florida weakened motorcycle helmet law: effects on death rates in motorcycle crashes.Traffic Injury Prevention 7(1):55-60.  Helmet use among fatally injured motorcyclists younger than 21 declined from 72 percent before the law change to 55 percent after.

11 How have courts resolved challenges to helmet use laws?

Courts have repeatedly upheld motorcycle helmet use laws under the U.S. Constitution. In 1972, a federal court in Massachusetts told a motorcyclist who objected to the law: "The public has an interest in minimizing the resources directly involved. From the moment of injury, society picks the person up off the highway; delivers him to a municipal hospital and municipal doctors; provides him with unemployment compensation if, after recovery, he cannot replace his lost job; and, if the injury causes permanent disability, may assume responsibility for his and his family's subsistence. We do not understand a state of mind that permits plaintiff to think that only he himself is concerned." The U.S. Supreme Court affirmed this decision without even hearing arguments in the case. Simon v. Sargent, 346 F. Supp. 277 (D.Mass.), aff’d, 409 U.S. 1020 (1972).

12 Do people support mandatory helmet use laws?

According to a 2000 national telephone survey, 81 percent of respondents reported that they favored mandatory helmet use laws for motorcyclists. Support was more prevalent among females (88 percent) than males (72 percent) and among non-motorcyclists (83 percent) than those who drove motorcycles (51 percent). Support was higher in states requiring all riders to wear helmets (84 percent) compared with states with lesser requirements (75 percent) or no requirements (79 percent). National Highway Traffic Safety Administration. 2000 Motor Vehicle Occupant Safety Survey. Report no. DOT HS-809-389. Washington DC: U.S. Department of Transportation.

In an Institute survey of motorcyclists conducted in 2009, 45 percent said they favor universal helmet laws. McCartt, A.T.; Blanar, L.; Teoh, E.R.; and Strouse, L.M. 2011. Overview of motorcycling in the United States: a national telephone survey. Journal of Safety Research 42(3):177-194.  Those who favor universal laws were more likely to report that they believe helmets keep riders safer than those who do not favor universal helmet laws (87 percent vs. 65 percent). Among motorcyclists who reported not always wearing helmets while riding, 57 percent said that a helmet law would encourage full time helmet use.