Injuries remain as one of the most important health problems facing pediatricians today. In the adolescent years, motor vehicle-related injuries constitute the greatest cause of trauma, morbidity, and mortality. In fact, motor vehicle injuries alone account for almost one half of all deaths in 16 to 19 year olds. The motor vehicle occupant death rate for 16 to 19 year olds per 100 million miles traveled is the highest of any age group. 1
In 1985, there were 2,831 motor vehicle deaths in 15 to 1 7 year olds and 4, 830 in 18 to 20 year olds (Table 1). Males accounted for the majority of deaths in both age groups. A significant proportion o( deaths involved teenagers who were passengers in motor vehicles, as well as those who were drivers.
This article will briefly review the available options for prevention of motor vehicle injuries in adolescents. The potential strategies include high school driver's education programs, driving curfew laws, delaying the age of licensure, raising the minimum age for purchase of alcohol, legislation requiring mandatory seat belt and motorcycle helmet use, and airbags (Table 2). What is the evidence for the effectiveness of these approaches?
High school driver education seems to be a very reasonable option for improving teenage driver performance and decreasing crash involvement. For years, studies of driver's education supported this assumption in that students who took driver's education had lower crash rates than those who didn't.2 However, these early studies suffered from important selection bias in who volunteered to take the courses. When driver's education was subjected to a controlled experiment in England, no differences in crash rates were noted between students assigned to take driver's education and those who were not.2
Two important studies in the United States have indicated that the net effect of driver's education is negative. Driver's education leads to increased numbers of teenage drivers, which in turn leads to an ina eased number of crashes. A study of 16 to 17 year old drivers in 27 states found no relationship between the rate of fatal crashes per licensed 16 to 17 year old drivers and the proportion of such drivers in the state who had taken a high school driver's education course. 3 However, the results showed that 80% of 16 to 17 year olds taking driver's education were licensed one to two years earlier than the normal 18 years of age because of the driver's education class. More driver's education led to more licensed teenage drivers, who did not have better crash records. The study found that the net result was an increased number of teenage driver fatalities in states with a high proportion of teenagers taking driver's education.
Fatal Motor Vehicle Injuries United States, 1985
Further support comes from a natural experiment in Connecticut, where a number of cities and towns in 1976 and 1977 dropped high school driver's education after the state eliminated support for the program. This resulted in a 75% decrease in the rate of licensure among the 16 to 17 year old population in the areas where high school driver's education was eliminated. This was accompanied by a commensurate decrease in the rate of crashes among 16 to 17 year olds in those communities.4
In short, high school driver's education does not make teenagers better drivers, while it allows them to become licensed at an earlier age. The net effect is to increase the number of young drivers at risk, resulting in a subsequent increase in the number of crashes among these drivers.
Nighttime motor vehicle fatality rates among teenagers are much higher than during the day. Overall, less than 20% of the miles driven by teenagers take place between 9 PM and 6 am whereas more than one half of their fatalities occur during that period.5 Among 16 year old male drivers, their nighttime fatality rate is four times higher than their daytime rate.6
One approach to decreasing the number of teenage motor vehicle fatalities has been the institution in a number of states of curfew laws. These laws restrict the nighttime driving of young, usually 16 year old, drivers. An analysis of the effects of the laws in four states with relatively strict laws (New York, Maryland, Pennsylvania, and Louisiana) compared the motor vehicle crash and injury involvement of 16 year olds during curfew hours in these four states to those in four comparison, non-curfew states. 7 The results indicate that crashes in 16 year old drivers during curfew hours were reduced by 69% in Pennsylvania and 62% in New York. In addition, the curfew laws, themselves appeared to decrease the number of 16 year olds who had obtained licenses in these states.
Strategies for Preventing Motor Vehicle Injuries Ib Adolescents
These laws appear to be acceptable to teenagers. In a phone survey conducted by the Insurance Institute for Highway Safety, two thirds of New York and 80% of Pennsylvania teens surveyed say they favor some type of nighttime curfew for new teenage drivers.8
MINIMUM LICENSING AGE
One potential way to reduce the number of teenagers involved in motor vehicle crashes is to delay the age of licensing. This strategy was examined in a study analyzing teenage crash involvement in three states in the same geographic region of the country but with different minimum licensing ages: Connecticut (16 years and 30 days), Massachusetts (16 Vi years) and New Jersey (17 years).9 New Jersey had a very low rate of driver deaths among 16 year olds, but the same rate of death for passengers, bicyclists, and pedestrians as compared with the other two states. Although there was a slightly increased rate of driver crashes among 17 year olds in New Jersey, the law had a positive net effect on crash involvement of young drivers.
These data indicate that increasing the minimum age for licensing can result in a reduction of teenage motor vehicle deaths. States where the age for licensing is as low as 14 or 15 should carefully examine the potential effect of such a legislative change.
AGE FOR LEGAL PURCHASE OF ALCOHOL
In 1985, 31% of 16 to 19 year old drivers in fatal motor vehicle crashes had been drinking at the time of the crash; 20% were legally intoxicated with blood alcohol levels of 0.01 gms% or higher.1 Almost two thirds of deaths involving young drinking drivers occur on Friday, Saturday, or Sunday, and 70% occur between 8 PM and 4 am.
One public policy shown to affect drunk driving among teenagers is legislation raising the minimum age for purchase of alcoholic beverages from 18 to 19, 20 or 21. In Michigan, the legal drinking age was raised from 18 to 21 in December 1978. An analysis of alcohol -related crashes among 18 to 20 year old drivers showed that the actual number of crashes in 1979 was 31% lower than expected, while among drivers 21 to 24 years of age, crashes were 9% higher than expected. 10 In a similar study of 26 states that had raised the legal age for purchase of alcohol since 1975, there were 13% fewer nighttime crashes of young drivers covered by these laws.11
As a result of these studies, the Presidential Commission on Drunk Driving recommended in 1983 that all states "immediately adopt 21 years of age as the minimum legal purchasing and public possession age for alcoholic beverages."
The approaches described above all aim to prevent the teenager from being involved in a motor vehicle crash. However, much of the recent work in the field of injury control has emphasized the need to move beyond this approach and address methods to prevent injury when a crash does occur. One of the most important strategies is occupant restraints - seat belts and airbags.
Lap-shoulder belts, here referred to as seat belts, have been shown to be about 45% effective in reducing the likelihood of a fatality in a motor vehicle crash. I2 Studies examining voluntary seat belt use among 16 to 18 year old high school students ranged from 1% to 21%, varying with the socioeconomic status of the area in which the school was located. 15 These findings were not very different from the surveys conducted by the National Highway Traffic Safety Administration, showing that pre-mandatory use law rates among all drivers were in the range of 12% to 20%.
Educational programs in and of themselves have been shown to have little effect on belt use. Because of this, many states (beginning with New York in January 1985) have passed laws generally requiring front seat passengers to be restrained with a lap-shoulder harness. Studies have indicated large increases in belt use in states in the first month after the laws were enforced.14 In New York, belt use went from 43% to 81%; in New Jersey from 25% to 62%; in Illinois from 39% to 50%. However, belt use has been found to fall off in the months following this initial upswing. In all studies, use was lower for teenagers and young adults than for those over 24 years of age.
Police enforcement has been found to have a major effect on maintaining high belt usage rates. 15 A special demonstration study in Elmira, New York increased belt use to 77%. Enforcement and publicity campaigns are feasible methods of increasing compliance with belt use laws.
An alternative to seat belts is passive restraints, best exemplified by the airbag. These devices require no cooperation on the part of the driver or passenger. They work automatically in the event of a collision and are as effective as seat belts in preventing injury, if not more so. Fortunately, motor vehicle manufacturers in the United States are finally responding to the call for airbags and are equipping an increasingly higher proportion of new cars with these devices.
In 1985, motorcycle crashes claimed 4,570 lives in the United States. ' One half of these deaths occurred to teenagers and young adults between the ages of 15 and 24 years. Nonfatal motorcycle injuries also show a sharp peak at age 18. Available data indicate that a substantial proportion of these deaths involve head injury; the effectiveness of helmets in preventing motorcycle fatalities is approximately 27%.16 During the period from 1967-1977, 47 states passed laws requiring helmet use by motorcyclists. Following the removal of a financial penalty for not having these laws by Congress in 1977, 28 states repealed or weakened their helmet use laws. There was a large decrease in helmet use (from 95% to 100% with the law) to approximately 50% after repeal. As a result, there was a substantial increase in motorcycle fatalities in these states of approximately 25%. 17 States in which these laws have been reinstated have experienced a subsequent improvement in motorcycle fatality rates.
We as physicians and health professionals are very cognizant of the importance of motor vehicle injuries among adolescents. The general public is also aware of the toll taken by these injuries. Our task is to change the public's fatalistic attitude about these injuries, and to convey the belief that they can and should be prevented.
The prevention strategies outlined above involve changes in public policy. Many people are philosophically opposed to such changes as an infringement on the rights of individuals, be they teenagers, parents, or the populace at large. Injuries are a societal concern, however, because we are all affected by the loss of productive members of society and the costs of care for those left with lifelong disabilities. It is our responsibility as physicians to lead the effort to safeguard the health and welfare of our youth.
1. National Highway Traffic Safety Administration: Fatal Accident Reporting System 1985. Washington. DC. Department of Transportation, HS 807-071, Fehruary 1987.
2. Robertson LS: Injuries: Causes. Control Strategies, and Public Policy. Lexington, MA, Lexington Books, 1983, pp 92-94.
3. Robertson LS, Zador PL: Driver education and fetal crash involvement of teenaged drivers. AmJ Public Heath 1978; 68:959-965.
4. Robertson VS: Crash involvement of teenaged drivels when driver education is eliminated from high school. AmJ Public Health 1980; 70:599-603.
5. Williams AF: Nighttime driving and fatal crash involvement of teenagers. Accident Analysis and Prevention 1985; 17:1-5.
6. Robertson LS: Patterns of teenaged driver involvement in fetal motor vehicle crashes: Implications for policy choice. ) HeoWi ftilit Paiicy Law 1981; 6:303-314.
7. Preusser DF1 Williams AF, Zador PL1 et al: The effect of curfew laws on motor vehicle crashes. Poput Rep /E/ 1983; 6:115-128.
8. Insurance Institute for Highway Safety: Teenage driving curfew: A market research study to determine teenagers' awareness of and attitudes toward driving curfews in four states. March 1986.
9. Williams AF1 Karpf RS, Zador PL: Variations in minimum licensing age and fetal motor vehicle crashes. Am ] Public Health 1983; 73:1401-1403.
10. Wagenaar AC: Effects of the raised legal drinking age on motor vehicle accidents in Michigan. Highway Safety Research Institute Research Review 1981; 12 (Jan-Feh):l-8.
11. DuMouchel W, Williams AF, Zador PL: Raising the alcohol purchase age: Its effect on fetal motor vehicle crashes in 26 states. Washington, DC, Insurance Institute fòt Highway Safety. 1985.
12- Hedlund J: Casualty reductions resulting from safety belt use laws. OECD Workshop em effectiveness of seat belt use laws. National Highway Traffic Safety Administration, US Dept. of Transportation, Washington. DC, 1986.
13. Williams AF, Wells JK, Lund AK: Voluntary seat belt use among high school students. Accident Analysis and Prevention 1983; 15:161-165.
14. Williams AF, Wells JK. Lund AK: Shoulder belt use in four states with belt use laws. Accident Analysis and Prevention 1987; 19:251-260.
15- Williams AF, Lund AK, Preusser DF, et al: Results of a seat belt use law enforcement and publicity campaign in Elmira, New York. Accident Analysis and Prevention 1987; 19:243-249.
16. Evans L, Frick MC: Helmet effectiveness in preventing motorcycle driver and passenger fatalities. Warren, Ml, General Motors Research Laboratories, GMR-5602, October 30. 1986.
17. Chener TC, Evans L: Motorcyclist fatalities and the repeal of mandatory helmet wearing laws. Accident Analysis and Prevention 1987; 19:133-139.
Fatal Motor Vehicle Injuries United States, 1985
Strategies for Preventing Motor Vehicle Injuries Ib Adolescents