Motorcycles

Overview

Riding a motorcycle is inherently riskier than driving a car.

  • Motorcycles are less stable than passenger vehicles during maneuvers such as emergency braking and swerving and are less visible on the road.
  • When motorcyclists crash, they lack the protection of an enclosed vehicle, so they're more likely to be injured or killed.
  • Per mile traveled in 2016, the number of deaths on motorcycles in the U.S. was nearly 28 times the number in cars (NHTSA, 2018).

A proper helmet is the most important piece of motorcycle safety equipment.

  • The federal government estimates that wearing a helmet reduces the risk of dying in a crash by 37 percent (NHTSA, 2008).
  • Unhelmeted riders are 3 times more likely than helmeted ones to sustain traumatic brain injuries in the event of a crash (NHTSA, 2008).

An antilock braking system (ABS) reduces the risk of a motorcycle crash.

  • ABS prevents wheels from locking up, and that's crucial on a motorcycle. On a car, a lockup might result in a skid. On a motorcycle, it often means a serious fall.
  • The rate of fatal crashes is 31 percent lower for motorcycles equipped with optional antilock brakes than for the same models without them (Teoh, 2013).

Some kinds of motorcycles are riskier than others.

  • Supersport motorcycles have driver death rates about 4 times as high as that of cruisers and standards (Teoh & Campbell, 2010). These bikes are built on racing platforms, and their combination of light weight and high-horsepower engines means many models can quickly reach speeds of more than 160 miles per hour, which encourages risky behavior.

Latest news

Car tech could protect motorcyclists

Crash avoidance features on passenger vehicles could prevent or mitigate more than 8,000 crashes with motorcycles if the systems were designed to detect them.

October 19, 2017

Head injuries up after helmet law change

Trauma centers in Michigan are seeing more head injuries after the state rolled back its helmet law, new research shows.

September 1, 2016

By the numbers

A total of 5,172 motorcyclists were killed in crashes in 2017, more than double the number in 1997.

In 2008, motorcyclist deaths reached 5,307, accounting for 14 percent of total highway crash deaths. This is the highest number of motorcyclists killed in one year since the National Highway Traffic Safety Administration (NHTSA) began collecting fatal motor vehicle crash data in 1975. After declining 16 percent to 4,467 in 2009, motorcyclist deaths have been creeping up again.

Motorcycle owners have gotten older in recent decades. The typical motorcycle owner in 2018 was 50 years old (Motorcycle Industry Council, 2019). That contrasts with 1980, when the typical owner was 27 (Motorcycle Industry Council, Motorcycle Statistical Annual, 2000). In 1982, 3 percent of fatally injured motorcyclists were 50 and older; in 2017 over a third were.

More women are riding motorcycles. In 1990, 6 percent of owners were women. Today, 19 percent are (Motorcycle Industry Council, 2019). However, only 4 percent of motorcycle drivers killed in 2017 crashes were women, compared with 92 percent of the passengers who died.

Do helmets work?

Helmets decrease the likelihood of death and brain injuries from motorcycle crashes.

  • Studies have found that helmets reduce the risk of death by 37-42 percent (NHTSA 2008; Norvell & Cummings, 2002).
  • Unhelmeted motorcyclists are 3 times more likely than helmeted riders to suffer traumatic brain injuries (NHTSA, 2008).

Helmets that are sold as head protection for motorcyclists are required to meet federal performance standards. Helmets that don't meet the standards are known as "novelty helmets." A recent study found riders using novelty helmets were about twice as likely to die in crashes than riders wearing certified, full-face helmets (Rice et.al., 2017). NHTSA laboratory tests also suggest that head injuries are much more likely with novelty helmets than with certified ones (NHTSA, 2007).

Certified helmets are available in different styles, including half-coverage (covering the upper half of the head, generally above the ears), open-face and full-face. One study 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 et.al., 2011).

Some people claim that helmets increase the risk of neck injury and reduce peripheral vision and hearing. There is no credible evidence to support these arguments. More than a dozen studies have refuted the claim that helmets cause neck injuries (for example, Orsay et.al., 1994; Crompton et.al., 2011).

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 & McKnight, 1994). To compensate for any restrictions in lateral vision, riders turn their head more prior to a lane change. When it comes to hearing, sounds loud enough to be heard above the motorcycle's engine can be heard when wearing a helmet.

Other protective gear specifically designed for motorcyclist protection, such as jackets, pants, gloves and boots, have been shown to improve post-crash health outcomes after other types of severe injuries (de Rome et al., 2012).

Helmet laws

Universal helmet laws — state laws that require helmet use for all riders (operators and passengers) — are extremely effective.

In 2017, 97 percent of motorcyclists observed in states with universal helmet laws were wearing helmets. In states without such laws, helmet use was 48 percent (NHTSA, 2018). Use of helmets judged to be compliant with federal safety regulations was 87 percent among motorcyclists in states with universal helmet laws and 44 percent in states without such laws.

Helmet laws that apply only to young riders are virtually impossible to enforce.

Today, 19 states and the District of Columbia have universal helmet laws, 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.

Motorcycle helmet use laws by state in detail


The evolution of helmet laws

In the past, the federal government has intervened to encourage universal helmet laws.

The first time was in 1967, when the federal government began requiring states to enact motorcycle helmet use laws to qualify for certain federal safety and highway construction funds. 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 revoked federal authority to assess penalties for noncompliance. Between 1976 and 1978, eight states completely repealed helmet use requirements and 20 states weakened them to apply only to young riders.

In 1991, Congress created incentives for states to enact helmet use laws, but four years later it reversed itself.

When states enact universal helmet laws, deaths, injuries and medical costs go down. When they repeal those laws, the reverse often happens.

  • When California's helmet use law covering all riders took effect on January 1, 1992, the number of motorcyclist fatalities decreased 37 percent (Kraus et.al., 1994).
  • 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 et.al.,1992). Acute medical hospital charges for injured motorcyclists declined 38 percent.
  • 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. Serious injury crashes per registered motorcycle decreased 11 percent (Mounce et.al., 1992). But in September 1997, Texas again weakened its helmet law, requiring helmets only for riders younger than 21. Operator fatalities increased 31 percent in the first full year following the repeal (Preusser et.al., 2000).
  • Kentucky repealed its universal helmet law in 1998, followed by Louisiana in 1999. Motorcyclist deaths quickly increased in these states by 50 percent and 100 percent, respectively (Ulmer & Preusser, 2003).
  • 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 & McCartt, 2006). Hospital admissions of motorcyclists with head injuries increased 82 percent during the 30 months following the law change (Ulmer & Northrop, 2005). 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 — 4 times the $10,000 minimum medical insurance requirement.
  • Michigan weakened its universal helmet law in 2012 to exempt riders 21 and older who have at least $20,000 of medical insurance coverage and have either passed a motorcycle safety course or held a motorcycle license endorsement for at least two years. The change was associated with a 22 percent increase in the average insurance payment for injuries to motorcyclists (HLDI, 2013), as well as increased head injuries and neurological interventions, but no significant change in deaths (Carter et. al, 2017).

Motorcycle types

Motorcycles vary widely in their design, the type of rider they appeal to and their crash risk.

Street-legal motorcycles can be grouped into 10 different classes in a system developed by HLDI.

Cruiser

Cruisers mimic the style of American motorcycles from the 1930s to 1960s, such as Harley-Davidsons and Indians.

Standard

Standards have basic designs and upright riding positions, with low power-to-weight ratios that result in a user-friendly motorcycle.

Supersport

Supersports are consumer versions of racing motorcycles. Reduced weight and increased power allow for quick acceleration, nimble handling and high speeds.

Sport

Sport motorcycles are closely related to supersports. Sport bikes are capable of high speeds but don't have the acceleration, stability and handling of supersports. They generally have lower power-to-weight ratios than supersports.

Unclad Sport

Unclad sport motorcycles are similar to sport bikes and supersports in design and performance but without plastic body fairings or windscreens.

Sport Touring

Sport-touring motorcycles are similar to sport bikes but tend to be heavier and equipped with touring features such as saddlebags, a rear trunk and larger seats. Typically, they have more substantial windshields and wind-deflecting fairings than sport bikes.

Touring

Touring motorcycles have big engines and fuel tanks plus room to haul luggage. They're often outfitted with antilock brakes, audio systems and cruise control.

Scooter

Scooters have small wheels, automatic transmissions and small engines, but larger scooters are becoming more popular.

Cruisers are the largest class of bikes. They accounted for 42 percent of registrations in 2018 (Teoh, 2019).

Registration-based death rates indicate that drivers of cruisers, standards, touring and sport-touring motorcycles have the lowest death rates.

Supersport motorcycles make up a small fraction of registered motorcycles, but their riders are overrepresented in fatal crashes. A 2010 IIHS study found that the driver death rate per 10,000 registered motorcycles for supersports was about 4 times as high as the rate for motorcyclists who rode cruisers or standards (Teoh & Campbell, 2010).

Motorcycle ABS


Studies of fatal crashes, insurance claims and test track performance all confirm the importance of antilock braking systems (ABS) for motorcycles.

The rate of fatal crashes is 31 percent lower for motorcycles equipped with optional ABS than for those same models without ABS (Teoh, 2013).

Collision insurance claims for motorcycles with ABS are filed 20 percent less frequently than for motorcycles without it — 31 percent when the ABS bikes have combined brake controls (HLDI, 2013).

On the test track, both new and experienced riders stop more quickly with antilock brakes. Stopping distances improve on wet and dry surfaces alike (Austrian Road Safety Board, 2004; Green, 2006).

Braking on a motorcycle isn't the same as braking in a car. Most motorcycles have separate brake controls for the front and rear wheels, and either wheel can lock up during hard braking. On a car, a lockup might result in a skid. On a motorcycle, it often means a serious fall.

Even skilled riders may accidentally overapply the brakes if a driver cuts them off or if road surfaces become unexpectedly slick. ABS allows riders to brake fully without fear of locking up. The system automatically reduces brake pressure when a lockup is about to occur and increase it again after traction is restored.

How ABS works

Motorcycle ABS graphic
(Robert Bosch LLC)

An antilock braking system works by constantly measuring wheel speed. One common way to do this is with a small grooved ring near the brake disc often called a tone wheel. The wheel speed sensor sends the tone wheel readings to the ABS unit, which can determine whether the wheel is about to stop rotating. If it is, wheel speed information is used to adjust the pressure from the brake cylinder on the brake caliper multiple times per second.

ABS doesn't affect normal braking — you notice it only in an emergency. Both conventional braking systems and combined braking systems, which link one or both controls to both wheels, can have ABS.

In the European Union, ABS has been required on motorcycles with an engine displacement of more than 125 cubic centimeters since 2016. Although there is no requirement in the U.S., the technology is widely available. Among 2018 motorcycles, 55 percent of models come with standard ABS, and another 20 percent offer it as an option.