1) Introduction


Motorcycle crashes are an important cause of morbidity and mortality in the United States, resulting in a litany of acute injuries, with the majority of deaths from head injuries (53%), and the second most common from chest or abdominal injuries (7-25%).(1) Additionally, motorcycle crash-related injuries can result in long term chronic impairment with extensive monetary cost.

Per vehicle mile traveled, motorcyclists have a 34-fold higher risk of death in a crash than people driving other types of vehicles.(1) And while 20 percent of passenger vehicle crashes lead to injury of death, as many as 80% of motorcycle crashes cause significant morbidity or death.(2) Even more lopsided, among fatalities in two vehicle crashes involving motorcycles and passenger vehicles, 98% of the fatalities were the motorcycle riders, while only two percent were in passenger vehicle occupants. (3)

Clearly, motorcycle related injuries are an important public health concern, and a major source of injuries and death, with resultant significant social and economic burden.

2) Magnitude and Trends

Compared to other forms of transit, motorcycle riding is known to represent an elevated risk of injury and death. In fact, it has been consistently demonstrated to be associated with an elevated fatality rate compared to passenger vehicles. Most recent data demonstrate a fatality rate of 73 deaths/100,000 registered motorcycles in 2005, compared to 14/100,000 registered passenger vehicles. (4)


"Motorcycle Safety Program." National Highway Traffic Safety Administration Jan. 2003. http://www.nhtsa.gov/people/injury/pedbimot/motorcycle/ motorcycle03/McycleSafetyProgram.pdf

Notably, the motorcycle fatality rate is known to be disproportionately elevated compared to the percent of registered vehicles in the country and the percent of vehicle miles traveled (VMT). In fact, in 2001, it was noted that motorcycles represented 2.2% of all registered vehicles in the US, and accounted for 0.34% of the VMT, but accounted for 7.6% of the total traffic fatalities for that year. (2)


"Motorcycle Safety Program." National Highway Traffic Safety Administration Jan. 2003. http://www.nhtsa.gov/people/injury/pedbimot/motorcycle/ motorcycle03/McycleSafetyProgram.pdf

The motorcycle riding community has experienced tremendous growth during the last two decades. From 1997-2005 motorcycle registrations jumped 63%, from 3,826,373 to 6,227,146. (4) Additionally, new sales have shown significant a significant increase as well, up approximately 91% since 1997. (2) However, fatalities have risen disproportionate to sale, rising yearly from 1997 to 2006, from 2,116 to 4,810, amounting to a 127% increase. (4)


"Action Plan to Reduce Motorcycle Fatalities." U.S. Department of Transportation Oct. 2007. http://www.nhtsa.gov/DOT/NHTSA/Communication%20&%20

Additionally, this increase in motorcycle related fatality has occurred while overall fatality rate for registered vehicles has actually declined modestly from 1997. (4) With the decrease in overall traffic related fatality rate, motorcycle fatalities now represent a much more substantial proportion of roadway fatalities, up from 5.0% in 1997, to a disturbing 11.3% in 2006. (4)

Though young adults aged 20-29 continue to be the demographic most affected by motorcycle related fatality, from 1997 to 2006, adults over the age of 40 had the most dramatic increase. In fact, there has been a 172% increase in fatalities in adults aged 40-49, 307% increase in adults aged 50-59 and 280% increase in those over 59 years. (4) In tandem with this, motorcycle ownership amongst those 40 years of age and older has increased significantly, from 15.1% in 1980 to 43.7 percent in 1998. (2)


"Action Plan to Reduce Motorcycle Fatalities." U.S. Department of Transportation Oct. 2007. http://www.nhtsa.gov/DOT/NHTSA/Communication%20&%20

"Action Plan to Reduce Motorcycle Fatalities." U.S. Department of Transportation Oct. 2007. http://www.nhtsa.gov/DOT/NHTSA/Communication%20&%20

While the number of fatalities has increased in all categories from 1997 to 2006, and the largest number of fatalities occurred in the 501-1,000 cc engine size group (41%), the largest increase in fatalities was in the 1,000 to 1,500 cc group (38%). (4) Additionally, 2/3 of the motorcyclists killed in this group were over 40. (4)

3) Economic Impact


The economic burden due to injuries and death from motorcycle crashes is substantial, estimated at $12 billion per year in the US. (5) Despite claims to the contrary, evidence indicates that the majority of the burden is paid by the general public, through higher insurance premiums and taxes, as well as through lost tax revenue. (5,6). In fact, in a study of 105 motorcyclists hospitalized for major trauma, 63.4% of the care was ultimately paid by public funds, with Medicaid accounting for more than half of all charges. (6) And while 60% of the direct cost was accounted for in the initial hospitalization, 23% was spent on rehabilitation and repeat hospitalizations. (6)

4) Risk Factors


-The majority of fatalities were in White/Caucasians (77%), followed by African Americans (9%), Hispanics (7%) and Native Americans (1%). (4)

-Over the last 10 years, 90% have been male. (4)

-Younger age associated with increased risk of fatal accidents. (1)
-The age group >40 have experienced rapidly increasing fatality rate since 1997. (4)

-More people are killed in motorcycle crashes on rural roads than 20 years ago. Additionally, half of all crashes are on rural roads. (2)

Helmet use
-A Cochrane Review demonstrated up to 69% decrease in odds of death with helmet use. Additionally, some studies have shown no effect on neck injuries and a protective effect on facial injuries. (7)
-45% of fatally injured motorcycle riders did not wear helmets. (4)

Protective equipment use
-Protective clothing decreases risk of soft tissue damage, but not fractures. (1)

Mandatory Helmet Laws
-68% of motorcyclists in states requiring helmet use wore DOT compliant helmets in 2006, compared to 37% in states not requiring helmets. (4).

Alcohol/Drug Abuse
-Motorcycle riders who have imbibed alcohol are more likely to lose control of their motorcycle than nondrinking riders. (1)
-49% of motorcycle crash deaths in US police reports were attributed to alcohol use, compared to 26% in other motor vehicle crash deaths. (1)
-More than 60% of all motorcycle deaths with young riders (15-29 years old) involved alcohol. (1)
-Among fatally injured young riders, one third used a combination of alcohol, and other drugs like cannabis, benzodiazepines or cocaine (1).
-32% of motorcycle riders treated in a Maryland trauma center from 1990-1991 had used cannabis prior to the crash, compared to 2.7% in car drivers. (1)

Riding speed
-Higher speeds are associated with more serious injuries. (1)
-When crash speeds exceed 50 kph, there is a reduction in helmet effectiveness in preventing death. (1)
-Speeding in fatal motorcycle crashes occurs at twice the rate for motorcycle riders compared to drivers of cars or light trucks. (1)
-Speeding is considered to be responsible for almost 2/3 of the motorcycle deaths in single vehicle crashes. (1)
-In addition to excessive speed, inappropriately slow speed for traffic conditions is associated with high risk of two-vehicle collisions. (1)

Risk taking behaviors
-Risk taking behaviors like speeding, drinking while riding, not using a helmet while riding, unlicensed riding, running yellow lights, and driving with too little headway are all thought to be risk factors for injury and death, and also appear to be correlated with each other. (1)

Inexperienced riding
-Less driving experience is associated with higher risk of motorcycle crashes and injuries. (1)

Insufficient rider training
- Cochrane Review reveals no evidence of significant difference in crash, injury or offence rates following rider training. (8)

Lack of motorcycle licensure
-Associated with higher risk of crashing as well as with serious motorcycle injury (1).
- Among fatally injured riders, 75% had a valid license, with lowest license rate in the below 20 age group (1).

Riding a motorcycle that is not owned by the user
-Those that borrowed a motorcycle were more likely to have a crash at night, to crash while attempting a turn, or commiting a traffic violation (1).

Lack of conspicuous lights/riding wear
-2/3 of care drivers claimed not to have seen the motorcycle or saw it too late to avoid a collision. (1)
-High visibility clothing and white helmets have been shown to reduce risk of crash compared to other methods. (1)
-Use of high or low beam headlights during the day appears to be helpful. (1)

Night riding
-Almost 60% of all single vehicle crashes occur at night (2)

Size of motorcycle ridden
-41% of motorcycle fatalities occurred in 500-1000 cc category and 38% in 1000-1500 cc category. (4)
-There were increases in all engine size categories from 1997 to 2006, but the largest increase was in 1000-1500 cc. (4)

5) Factors Limiting Progress


Registrations and new motorcycle purchases continue to skyrocket, bringing more motorcycles onto increasingly crowded roadways. (4) With the America's increasing income disparity, continued economic recession and elevated gas prices, coupled with a relatively low initial investment when purchasing a motorcycle, low cost of maintenance, higher gas efficiency and easier parking, motorcycles have become a cost-effective strategy for transportation. These assure continued presence of motorcycles on American roadways, as well as increased use in less than optimal riding conditions. However, by attending to factors impeding progress, injury rates may be stabilized.

While several factors limit progress (substance use while riding, lack up uptake of methods to increase conspicuity of motorcycles, continued risk-taking behaviors associated with riding, etc.), one of the most important factors is resistance against helmet use and helmet laws. Evidence that helmets save lives is quite strong, at this point. (7) In addition, evidence indicates that this is not simply an issue of personal liberty. The economic and social costs of motorcycle accidents affect all Americans, not simply those involved in the crash. (5,6)

Research has shown quite convincingly that when universal helmet laws are instituted, helmet use increases, and when these laws are repealed, helmet use decreases. (9) Additionally, evidence indicates that when helmet laws are repealed, motorcycle deaths and injuries increase. (9) In addition, when economic costs are calculated, states with universal helmet laws save, on average, triple the costs per registered rider compared to states without mandatory helmet laws. (9)


"CDC - Motorcycle Safety Guide - Motor Vehicle Safety - Injury Center." Centers for Disease Control and Prevention. Web. 24 Mar. 2012.


"CDC - Motorcycle Safety Guide - Motor Vehicle Safety - Injury Center." Centers for Disease Control and Prevention. Web. 24 Mar. 2012.

6) Haddon's Matrix


7) Haddon's Ten Strategies

1) Prevent the creation of the hazard in the first place:

  • a) Eliminate production of motorcycles
  • b) Do not ride a motorcycle
  • b) Prevent unauthorized use of motorcycles, especially by youths
  • Of the 10 strategies, some are much more realistic than others. While the most efficacious would undoubtedly be to eliminate all use of motorcycles, that is unlikely to occur at this point.

2) Reduce the amount of hazard brought into being:

  • a) Limit maximum speed/power of motorcycles
  • b) Increase safety standards on motorcycles - improved braking, turning capability, etc.
  • Limiting the speed of motorcycles and increasing safety standards would both be effective at decreasing risk of motorcycle related fatality. However, it is doubtful that speed could be limited to an extent necessary to save lives, due to consumer backlash. However, increasing safety standards on motorcycles is both feasible and appropriate.

3) To prevent the release of a hazard that already exists:

  • a) Greater enforcement of requirement of licensure to ride motorcycle
  • b) Graduated licensure for youths
  • c) Increase motorcycle conspicuity - noticeable jackets/helmets, use of headlights/taillights
  • d) Increase automobile driver awareness of motorcycle riders via training or technology to alert them to the presence of nearby motorcycles
  • e) Increase visibility of hazards
  • f) Properly maintain all roads.
  • g) Verify that streets are swept clean of dust/sand/gravel
  • h) Warn rider of inclement weather conditions
  • To the contrary of the last two strategies, many of the factors listed in this category are already in use, and the ones that are not used or are not widespread yet, are quite feasible, effective and appropriate.

4) Modify Rate/spatial distribution of release of hazard:

  • a) Enforce laws to reduce speeding and reckless driving
  • b) Decrease speed limits
  • Greater enforcement of speeding and reckless driving would likely effective and feasible, however, it would require monetary investment in law enforcement. Decreasing the speed limit is likely not feasible, as evidenced by historical backlash due to decreased speed limit to 55 mph.

5) Separate in time or space the hazard and that is to be protected:

  • a) Do not allow motorcycle riding during inclement weather
  • b) Do not allow motorcycle riding during the night
  • c) Have motorcycle only lanes/roads
  • d) Do not place signs/posts/poles at the side of roads
  • Due to concerns regarding infringements on personal liberty, prohibiting night riding and riding in inclement weather would be unlikely to pass. However, educating motorcycle riders regarding these hazards may be useful. Additionally, the capital investment needed in motorcycle only lanes would likely be prohibitive. Efforts to removes signs and poles at the sides of roads have already begun, though this will be a long process.

6) Separate the hazard from host by interposition of material:

  • a) Mandate helmet use
  • b) Motorcycle air-jackets
  • c) Place compressible material at sides of roads to buffer falls
  • d) Pad obstacles at the side of the road like signs, poles, posts, etc.
  • e) Pad outsides of automobiles and trucks
  • Mandatory helmet laws are an issue that should be reconsidered, as they have the potential for significant decreases in morbidity and mortality. Though they haven't been invented yet, other varieties of personal protective equipment, like air-jackets, may be a useful idea in the future. Other efforts to buffer accidents by padding obstacles, vehicles and the roadside are not widely feasible.

7) To modify the basic quality of the hazard:

  • a) Reduce speed limit or reduce speed of the motorcycle itself.
  • b) Decrease roll over risk - by adding a 3rd wheel
  • c) Use breakaway design for poles at side of road
  • As noted above, lowering the speed of a motorcycle could decrease the basic quality of the hazard. However, for reasons listed above, this is not really feasible on a large scale. One consideration is that many new motorcycles on the road are scooters, which do have an absolute upper limit of 35-45 mph. Adding a third wheel for stability has already occurred, but this is unlikely to achieve widespread use, due to entrenched ideologies. Also, breakaway signs at roadsides are feasible, but are likely of lower benefit for motorcycles compared to cars.

8) To make that to be protected more resistant to damage from the hazard:

  • a) Increase the overall health and resilience of motorcycle riders through proper diet, strength training, smoking cessation, etc.
  • b) Prohibit motorcycle use in those of elevated age or with severe chronic disease
  • Point A is a wonderful idea, which should be encouraged for all Americans. However, we live in an increasingly unhealthy culture, and because of this, this is a rather unfeasible option. Point B is completely unfeasible, due to the need to preserve personal liberty.

9) Countering the damage that has already been done:

  • a) Institute a strong emergency medical technician (EMT) program
  • b) First responder training for general public
  • c) Ensure immediate access to medical care
  • d) Efficient emergency reporting system
  • e) Automatic crash reporting systems installed into motorcycles
  • f) Available ambulance and helicopter system for evacuation
  • g) Maintaining reserves of blood products for acute resuscitation
  • h) Cooling protocol for those with traumatic brain injuries (TBI)
  • While these strategies are directly dependent upon the location an accident occurs, they are quite appropriate, and deserve emphasis. Nonetheless, it is important to realize that these strategies are after the fact, and thus are slightly suboptimal, especially when compared to the strategies suggested in 1-7.

10) Stabilize, repair and rehabilitate:

  • a) Strong emergency department (ED) programs.
  • b) Strong trauma surgery programs.
  • c) High quality local hospitals.
  • d) High quality rehabilitations programs.
  • e) Retraining programs for those with subsequent impairment and disability
  • These strategies are also post-injury. Like strategies in 9, these also are quite appropriate, though feasibility of local care is dependent on the region.

8) Further Research Questions

  1. Why those aged >40 are the fastest growing segment for motorcycle mortality?
  2. Is there a difference in reduction in morbidity and mortality based on the type of helmet?
  3. What is the reason why some helmets fall off in crashes when placed on correctly?
  4. Is a motorcycle airbag jacket efficacious and feasible?
  5. At what blood alcohol concentration should a motorcycle rider be considered significantly impaired?
  6. What type, if any, of riders' education is beneficial for motorcycle riders?
  7. What effect would a graduated driver's license program have on youth and adult motorcycle fatality rates?

9) References

  1. Lin, Mau-Roung, and Jess Kraus. "A Review of Risk Factors and Patterns of Motorcycle Injuries." Accid Anal & Prev 41 (2009): 710-722.
  2. "Motorcycle Safety Program." National Highway Traffic Safety Administration Jan. 2003. http://www.nhtsa.gov/people/injury/pedbimot/motorcycle/ motorcycle03/McycleSafetyProgram.pdf
  3. Longthorne, Anders, Cherian Varghese, and Umesh Shankar. "Fatal Two-Vehicle Motorcycle Crashes." National Highway Traffic Safety Administration. (2007).
  4. "Action Plan to Reduce Motorcycle Fatalities." U.S. Department of Transportation Oct. 2007. http://www.nhtsa.gov/DOT/NHTSA/Communication%20&%20 consumer%20Information/Articles/Associated%20Files/4640-report2.pdf
  5. Naumann, RB, AM Delinger, E Zaloshnja, BA Lawrence, and TR Miller. "Incidence and Total Lifetime Costs of Motor Vehicle Related Fatal and Nonfatal Injury by Road User Type." Traffic Inj Prev. 11.4 (2005): 353-360.
  6. Rivara, Frederick, Barbara Dicker, Abraham Bergman, Ralph Dacey, and Clifford Herman. "The Public Cost of Motorcycle Trauma." JAMA 260.2 (1988): 221-223.
  7. Liu, BC, R Ivers, R Norton, S Boufous, S Blows, and SK Lo. "Helmets for Preventing Injury in Motorcycle Riders." Cochrane Database Syst Rev 1 (2009): 1-44.
  8. Kardamanidis, K, A Martiniuk, RQ Ivers, MR Stevenson, and K Thistlethwaite. "Motorcycle rider training for the prevention of road traffic crashes." Cochrane Database Syst Rev 10 (2010): 1-48.
  9. "CDC - Motorcycle Safety Guide - Motor Vehicle Safety - Injury Center." Centers for Disease Control and Prevention. Web. 24 Mar. 2012. .
  10. Daniello, Allison, and Hampton Gabler. "Fatality risk in motorcycle collisions with roadside objects in the United States." Accident Analysis and Prevention 43 (2011): 1167-1170.
  11. Derrick, Allison, and Lee Faucher. "Motorcycle helmets and rider safety: A legislative crisis." Journal of Public Health Policy 30.2 (2009): 226-242.
  12. Pai, Chih-Wei. "Motorcycle right-of-way accidents A literature review." Accident Analysis and Prevention 43 (2011): 971-982.