DEPARTMENT OF TRANSPORTATION
NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION

TECHNICAL SUMMARY


"PREPARED FOR THE DEPARTMENT OF TRANSPORTATION, NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION UNDER CONTRACT NO.: DTNH22-97-D-05018. THE OPINIONS, FINDINGS, AND CONCLUSIONS EXPRESSED IN THIS PUBLICATION ARE THOSE OF THE AUTHORS AND NOT NECESSARILY THOSE OF THE NATIONAL HIGHWAY TRAFFIC SAFETY ADMINISTRATION."

Youth drinking and driving in the United States decreased spectacularly in the past two decades. The best measure comes from fatal crash involvements: the number of drinking drivers under the age of 21 in fatal crashes dropped 61 percent, from 4,393 in 1982 to 1,714 in 1998. While 43 percent of young drivers in fatal crashes had a positive BAC in 1982, only 21 percent did in 1998. In comparison, the number of drinking drivers aged 21 and above dropped only 33 percent during this time.

Young Drinking Drivers, Fatal Crashes
FARS
Graph of Young Drinking Drivers, Fatal Crashes, FARS

Percent of Young Drivers with Alcohol
FARS
Graph of Percent of Young Drivers with Alcohol FARS

This report investigates the causes of this substantial decrease. It documents the changes in youth drinking and driving, and in youth drinking, and compares the changes across states and regions. It analyzes the effects of the National Minimum Drinking Age and state zero tolerance laws. It examines the influence of programs directed at youth drinking and driving, such as SADD (originally Students Against Driving Drunk, now Students Against Destructive Decisions) and the large variety of programs promoting healthy choices and lifestyles for youth. It considers the effects of factors not directed specifically at youth, such as adult drinking and driving measures and broad socioeconomic trends. It compares influences and trends in the United States with those in Canada. It concludes with recommendations on how to reduce youth drinking and driving even further.

Youth Drinking and Driving - National Trends

Nationally, youth drinking and driving as measured by fatal crash involvements and by self-reported drinking and driving behavior decreased substantially from 1982 to 1998. Most of the decrease took place between 1982 and 1992. Young drivers of all ages up to 21 reduced their drinking and driving by similar amounts. A small portion of the decrease in youth fatal crash involvements is due to a decrease in the number of young persons in the population.

Youth Drinking and Driving - Regional and State Trends

Youth drinking driver fatal crash involvements decreased substantially in all regions of the country and in most states. Drinking driver involvements per population decreased by more than 50 percent in 45 states. Many states followed the national pattern of a substantial drop from 1982 through the early 1990s, with little subsequent change. In 1998, youth drinking driver fatal crash involvements were about 5 per 100,000 population (or even lower) in the 10 best states and about 15 in the five worst states.

Youth Drinking

Youth drinking also decreased from 1982 to 1998, but not as much as youth drinking and driving. Evidence from Monitoring the Future and other surveys shows a consistent drop in self-reported drinking by both high school and college students under 21. This decrease occurred fairly uniformly across all regions of the country. However, most youth still drink; a majority drink at least monthly; a substantial minority binge drink regularly. Since about 1993 the number of youth in the U.S. has increased slightly and the number who admit to drinking has increased slightly, but youth drinking driver involvements in fatal crashes has remained approximately constant.

The decline in drinking accounts for some, but by no means all, of the decline in drinking and driving. Youth have separated their drinking from their driving more in 1998 than they did in 1982, and more than have drivers over 21. Drinking and driving has become less socially acceptable among youth, as measured by youth student attitudes and by the use and acceptance of designated drivers.

Minimum Legal Drinking Age Laws

Thirty-six states raised their minimum legal drinking age (MLDA) to 21 between 1983 and 1987 (the other 14 states had age 21 laws in effect before 1983) so that by 1988 MLDA was in effect in all states. MLDA 21 laws clearly reduced youth drinking and driving. The laws reduced youth drinking by reducing alcohol availability and by establishing the threat of punishment for alcohol use. But MLDA 21 laws do not work particularly well in practice, as youth still can obtain alcohol relatively easily and underage drinkers are highly unlikely to be detected and punished. MLDA 21 laws also may have encouraged youth to separate their drinking from their driving. The observations that youth drinking and driving decreased substantially more than youth drinking, and that youth drinking and driving after drinking both decreased in states that had MLDA 21 laws throughout the 1980s, suggest that MLDA 21 laws were not the only influence on youth drinking and driving during this period.

Zero Tolerance Laws

A zero tolerance law sets a maximum BAC of 0.02 or less for youth and suspends or revokes an offender's driver's license. All states and the District of Columbia adopted zero tolerance laws covering all drivers under 21 between 1990 and 1998. Zero tolerance laws also have reduced youth drinking and driving. They likely did so for two reasons: by deterring youth through the fear of losing their driver's license if they drive after drinking, and also by reinforcing the broad community disapproval of youth driving after drinking.

Youth Programs

States and communities conducted extensive youth drinking and driving programs in the past two decades. These programs seek to motivate youth not to drink and drive through positive means: by education on crash and injury risks posed by drinking and driving and the effects of alcohol use and abuse, by providing positive role models that discourage alcohol use, by establishing youth norms that do not include alcohol, and by encouraging youth activities that do not involve or lead to alcohol use. Other organizations concerned with traffic safety - insurance companies, automobile manufacturers, MADD, and many others - did the same through public education and specific program activities.

There is little direct evidence of the effects produced by these activities. Very few have been evaluated to determine their effects on youth knowledge, attitudes, behavior, traffic violations, or crashes. A few well-organized and well-funded community programs have reduced youth drinking and driving after drinking. Some school programs have affected students' knowledge and attitudes and may have affected their behavior. But there is no direct proof that most of the many youth traffic safety program activities not involving laws and enforcement had any direct effect on youth drinking and driving. There also is no proof that they did not. The accumulation of information, education, skills, role models, and the like provided by these programs may have been a crucial influence in the youth attitude, behavior, and crash changes that have occurred.

Drinking and Driving Measures Not Directed at Youth

In general, states that reduced overall drinking and driving the most from 1982 to 1998 also reduced youth drinking and driving the most. This suggests that states that took effective measures to reduce overall drinking and driving also saw the effect of these measures on youth drinking and driving. In addition, the travel, employment, and unemployment trends that influenced overall drinking and driving likely also affected youth drinking and driving.

The Canadian Experience

Canadian reductions in youth drinking and driving, measured both by fatal crash data and by surveys, followed virtually the same pattern as in the United States. But the Canadian reduction was not due to laws directed at youth: the drinking age did not change during this time and zero tolerance laws were implemented after the reduction had occurred. This means that the changes must have resulted from some combination of the difficult-to-assess educational and motivational programs and from other factors outside of traffic safety. This suggests that a substantial portion of the reduction in the United States also resulted from these same causes.

Conclusions

Three influences on youth drinking and driving are well-documented and well-understood: population changes, legal drinking age increases, and zero tolerance laws. However, these three by themselves account for only a portion of the observed decrease in youth drinking and driving. Influences from other factors - youth programs, other drunk driving measures, and factors completely apart from driving or drinking - can only be inferred. Something has worked spectacularly well in reducing youth drinking and driving. Some causes are known; some are not. The most prudent strategy would be to improve MLDA 21 and zero tolerance law enforcement, continue the programs directed at youth, and strengthen measures against all drinking and driving.