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).