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Motorcycle Helmets: What’s the Latest Research?. Michigan Traffic Safety Summit 2007. East Lansing, MI March 14, 2007. Anne T. McCartt. Motorcycle crashes National problem size and status. Per mile traveled, there were 34 motorcyclist deaths for every car occupant death in 2004
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Motorcycle Helmets: What’s the Latest Research? Michigan Traffic Safety Summit 2007 East Lansing, MI March 14, 2007 Anne T. McCartt
Motorcycle crashesNational problem size and status • Per mile traveled, there were 34 motorcyclist deaths for every car occupant death in 2004 • 4,439 motorcyclists died in crashes in 2005, more than double the all-time low in 1997 and 15% higher than in 2004 • Increase in deaths not fully explained by increased exposure; FHWA estimates that motorcycle registrations increased by 63% from 1997 to 2005
Motorcyclist deaths By age, 1975-2005 ≤ 29 years old 30-39 years old 40-49 years old 50+ years old
Driver error in crashes involving a motorcycle and a passenger vehicle 2005
Helmet use and alcohol-impairment among fatally injured motorcycle driversBy age, 2005
Helmets are primary countermeasure for reducing crash-related head injuries • About half of motorcyclist deaths during 1979-1986 were attributed to head injuries (Sosin et al., 1990) • Helmets reduce risk of dying in a crash by about 40% (Deutermann, 2004; Norvell & Cummings, 2002) • In a crash, unhelmeted motorcyclists are 3 times more likely than helmeted cyclists to suffer traumatic brain injuries (NHTSA, 2005) • Advances in helmet design and materials continue to increase effectiveness
Myths about helmets • Increase risk of neck injury: Many studies found that helmets reduce head injuries without increasing spinal and neck injuries (Orsay et al., 1994, 1995) • Obstruct peripheral vision: Helmets don’t reduce ability to see vehicle in adjacent lane (McKnight & McKnight, 1994) • Reduce hearing: No difference in hearing threshold with or without helmet; sounds audible above engine can be heard with helmet (McKnight & McKnight, 1994)
International universal motorcycle helmet laws • Indonesia • Japan • Malaysia • Thailand • Venezuela • Argentina • Australia • Brazil • Canada • India • Most countries in the European Union • Many other countries around the world
States with universal helmet laws 1976: Highway Safety Act removed authority to withhold funds from states without helmet laws 1995: Grants removed 1991: Incentive grants for helmet and safety belt laws 1967: Helmet laws required for states to qualify for federal highway funds
universal law no law or limited law Helmet use laws in U.S. statesJanuary 1997 compared with January 2007 Helmet use laws in U.S. statesJanuary 1997 NH ND WA MT VT MN ME SD WI OR ID WY NY MI MA IA NE PA IL OH IN RI NJ NV UT CO CT MO WV KS DE VA KY CA MD TN NC OK DC AR AZ NM SC MS AL GA LA TX FL AK HI
Observed motorcycle helmet use by universal helmet law status (percent)NHTSA
Observed DOT-compliant motorcycle helmet use by universal helmet law status (percent)NHTSA
Effects of motorcycle helmet laws • Based on studies of state law changes, helmet use approaches 100% with a universal helmet law and about 50% with no law or a partial law • Motorcyclist deaths and injuries decline when helmet use is mandated and increase after laws are repealed or weakened
Percent change in motorcyclist deaths after enactment of universal helmet laws
Percent change in helmet use and motorcyclist deaths after laws were weakened
Florida helmet law change • July 1, 2000: universal law weakened to exclude riders 21 and older with at least $10,000 in medical insurance • Secondary enforcement • Motorcyclist deaths almost doubled after law change
IIHS study of effects of Florida helmet law change on motorcyclist deaths • Motorcycle registrations up dramatically after change • No reliable data on motorcycle miles traveled • Compared motorcyclist deaths per 1,000 crashes before law change (1998-99) versus after (2001-02)
Observed helmet use before and after law change • Observed use of any helmet type declined from nearly 100% before law change to 53% after • Estimated DOT-compliant helmet use declined from 59% to 47% • Reliability of data on compliant vs. novelty helmet use not known
before after Deaths per 1,000 crashes by vehicle type before and after law change, Florida
before after Motorcyclist deaths per 1,000 crashes by rider age before and after law change, Florida
Motorcyclist deaths per 1,000 crashes before and after law change, Florida
Helmet use among fatally injured motorcyclists before and after law change (percent), Florida
Conclusions • Given involvement in a motorcycle crash, likelihood of death increased by 25% after law change • Increase occurred in all motorcyclist groups including riders younger than 21 • 117 motorcyclist deaths in 2001-02 could have been avoided if universal helmet law had been retained
NHTSA study of Florida helmet law changePreusser Research Group • Motorcyclist deaths per 10,000 motorcycle registrations up 21% during two years after law change (2001-2002), compared to two years prior (1998-1999) • Hospital admissions from head, brain, and skull injuries increased 82% after law change. • Average cost per case of treating these injuries went from $34,518 to nearly $40,000 • Less than one-quarter of treatment costs of injured motorcyclists would have been covered by $10,000 medical insurance requirement
www.iihs.org Anne McCartt Senior Vice-President, Research 703-247-1534 amccartt@iihs.org
< 29 years old 30-39 years old > 40 years old Motorcyclist deaths By age, 1975-2005
Probability of death in a motorcycle crash associated with helmet law change, age, and seating position, Florida