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Motor Vehicle Injury – Motorcycle Helmets: Universal Helmet Laws

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What the Task Force Found

About The Systematic Review

This Task Force finding is based on a systematic review of evidence from 71 studies with 78 study arms; 67 study arms evaluated motorcycle helmet laws in the United States (search period through August 2012). Comparison of universal and partial helmet law effectiveness came from 48 study arms.

The systematic review was conducted on behalf of the Task Force by a team of specialists in systematic review methods, and in research, practice, and policy related to motor vehicle injury prevention.

Context

In the United States, motorcycles account for about 3% of registered vehicles, 0.6% of vehicle miles traveled, and a disproportionate 14% of all road traffic fatalities (DOT, 2013). The Insurance Institute for Highway Safety maintains a current list of states and their helmet laws External Web Site Icon.

Summary of Results

Detailed information about study results are available in the Task Force Finding and Rationale Statement pdf icon [PDF - 672 kB].

The systematic review included evidence from 71 studies with 78 study arms. Of these, 67 study arms evaluated motorcycle helmet laws in the United States.

Included studies consistently showed that universal motorcycle helmet laws increase helmet use and decrease motorcycle-related deaths and injuries, and are substantially more effective than no law or partial motorcycle helmet laws.

These outcomes apply to riders of all ages, including younger operators and passengers who would have been covered by partial helmet laws.

Repealing Universal Helmet Laws

  • States that replaced universal helmet laws with partial laws or no laws experienced decreases in helmet use and increases in motorcycle-related deaths and injuries.
    • Helmet use: median decrease of 41 percentage points (21 study arms)
    • Total number of deaths: median increase of 42% (20 study arms)
      • Deaths related to head injuries: 6% and 65% increase (2 study arms)
    • Death rates:
      • Per registered motorcycle: median increase of 34% (18 study arms)
      • Per vehicle mile traveled: median increase of 23% (3 study arms)
      • Per crash: median increase of 21% (12 study arms)
    • Total number of non-fatal injuries: median increase of 41% (10 study arms)
      • Non-fatal head injuries: median increase of 74% (4 study arms)

Implementing Universal Helmet Laws

  • States that replaced partial helmet laws or no law with universal helmet laws consistently saw increases in helmet use and decreases in motorcycle-related deaths and injuries.
    • Helmet use: median increase of 54 percentage points (16 study arms)
    • Total number of deaths: median decrease of 31% (14 study arms)
      • Deaths related to head injuries: median decrease of 50% (9 study arms)
    • Death rates:
      • Per registered motorcycle: median decrease of 34% (12 study arms)
      • Per vehicle mile traveled: 43% decrease (1 study arm)
      • Per crash: median decrease of 17% (5 study arms)
    • Total number of non-fatal injuries: median decrease of 31% (9 study arms)
      • Non-fatal head injuries: median decrease of 51% (10 study arms)

Comparison of Helmet Laws across U.S. States

  • When compared with states that had partial laws or no law, states with universal helmet laws had higher rates of helmet use and lower rates of motorcycle-related deaths and injuries.
    • Helmet use: median of 53 percentage points higher (6 study arms)
    • Total number of deaths: median of 24% fewer (7 study arms)
      • Deaths related to head injuries: 47% fewer (1 study arm)
    • Death rates:
      • Per registered motorcycle: median of 12% lower (7 study arms)
      • Per vehicle mile traveled: median of 27% lower (2 study arms)
      • Per crash: 14% lower (1 study arm)
    • Total number of non-fatal injuries: 24% fewer (1 study arm)
      • Non-fatal head injuries: median of 33% fewer (3 study arms)
  • When compared with states that had no law, states with partial helmet laws had slightly higher rates of helmet use and lower rates of motorcycle-related deaths and injuries.
    • Helmet use: median of 5 percentage points higher (4 study arms)
    • Fatality rates:
      • Per registered motorcycle: 10% lower and 43% higher (2 study arms)
      • Per vehicle mile traveled: 8% fewer (1 study arm)
    • Non-fatal head injuries: 15% fewer (1 study arm)

Youth

All partial helmet laws in the United States include young riders, so helmet use among youth might be expected to be the same in states with partial and universal helmet laws. Evidence from 15 included study arms (12 from the U.S.) showed, however, that universal helmet laws were much more effective than partial laws in increasing helmet use and reducing deaths and head injuries among these younger riders.

Repealing Universal Helmet Laws

  • States that replaced universal helmet laws with partial helmet laws saw the following changes among younger riders:
    • Helmet use: median of 17 percentage point decrease (5 study arms)
    • Total number of deaths: median 125% increase (3 study arms)
    • Deaths per 1,000 crashes: decrease of 48% (1 study arm)

Implementing Universal Helmet Laws

  • States that replaced partial helmet laws or no law with universal helmet laws saw the following changes among younger riders:
    • Helmet use: 31 percentage point increase (1 study arm)
    • Total number of deaths: 48% decrease (1 study arm)
    • Non-fatal head injuries: median 27% decrease (3 study arms)

Comparison of Helmet Laws across U.S. States

  • When compared with states that had partial laws or no law, states with universal helmet laws had the following among younger riders:
    • Helmet use rates that were a median of 41 percentage points higher (2 study arms with 4 effect estimates)
    • Total number of deaths that was 31% fewer (1 study arm)
    • Total number of non-fatal injuries that was 8% higher (1 study arm)
    • Non-fatal head injuries that were 12% fewer (1 study arm)
  • When compared with states that had no law, states with partial helmet laws had the following among younger riders:
    • Helmet use rates that were a median of 10 percentage points higher (3 study arms)
    • The same number of total deaths (2 study arms)
    • The same rate of deaths per 10,000 registered motorcycles (1 study arm)

Summary of Economic Evidence

Detailed information about study results are available in the Task Force Finding and Rationale Statement pdf icon [PDF - 672 kB].

The economic review included 22 studies, of which 21 were from the U.S. (search period through June 2013). Three studies reported program costs, 18 detailed economic benefits, three included cost–benefit analyses, and one featured cost-effectiveness. Monetary values are reported in 2012 U.S. dollars.

Evidence shows the economic benefits of universal motorcycle helmet laws greatly exceed costs. Most benefits come from avoided healthcare costs and productivity losses.

  • Reported intervention costs included only the price of motorcycle helmets, which ranged from $1.3 million to $4.5 million per 100,000 motorcyclists per year.
  • Economic benefits:
    • The main economic benefits came from avoided healthcare costs and productivity losses.
      • Twelve benefit-only studies reported increased economic benefits after implementing universal helmet laws. Four of the studies were directly comparable and reported benefits ranging from $29.3 million to $96.1 million per 100,000 registered motorcycles per year.
      • Five benefit-only studies reported higher healthcare costs after repeal of universal helmet laws. Three of the studies were directly comparable and reported increased costs ranging from $1.8 million to $27.2 million per 100,000 registered motorcycles per year.
      • There was no statistically significant difference between average treatment cost for a head injury for riders in universal law states and those in partial or no law states.
  • Cost–benefit comparisons
    • Cost–benefit analyses in all three studies found that economic benefits greatly exceeded intervention costs. Benefit-to-cost ratios ranged from 2:1 to 20:1 and net savings ranged from $2.7 million to $86.9 million per 100,000 motorcyclists per year.
    • Cost–benefit ratios varied depending on the types of benefits considered. Studies considering a more complete set of benefits produced higher benefit-to-cost ratios. Benefit estimates included one or more of the following outcomes:
      • Healthcare costs avoided
      • Work productivity losses avoided
      • Non-monetary benefits such as the value of time spent with family or friends

Applicability

The available evidence indicates that universal helmet laws are effective in a range of contexts and populations, including:

  • U.S. and non-U.S. settings
  • Urban and rural areas
  • Motorcyclists of all ages
  • Males and females
  • Motorcycle riders and passengers

Evidence Gaps

Nearly six decades of research on this topic have answered primary research questions and demonstrated the effectiveness of universal helmet laws across population groups in various settings. Additional research and evaluation are needed to answer the following questions and fill existing gaps in the evidence base. (What are evidence gaps?)

  • What is the role of enforcement in helmet law effectiveness?
  • What is the impact of use of unapproved helmets on helmet law effectiveness?
  • What is the effectiveness of universal helmet laws in rural areas?
  • What is the impact of universal helmet laws on riders of low-powered motorized cycles (e.g., scooters, mopeds)? Currently, some states cover all types of low-powered cycles, while other states cover motorized cycles above certain thresholds, such as those designed to go over 30 mph.

Study Characteristics

  • Included studies evaluated helmet laws in the United States (67 study arms), Australia (1 study arm), Italy (4 study arms), New Zealand (2 study arms), Spain (2 study arms), and Taiwan (2 study arms).
  • In the United States motorcyclists had a mean age of 36.5 years and were mostly male (median: 91%).
  • Outside the United States, motorcyclists were slightly younger (mean age of 38.3 years) with fewer males (median: 67%).

Publications

There are no publications for this systematic review.