U.S. flag

An official website of the United States government

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.

Olson S, Gerstein DR. Alcohol in America: Taking Action to Prevent Abuse. Washington (DC): National Academies Press (US); 1985.

Cover of Alcohol in America

Alcohol in America: Taking Action to Prevent Abuse.

Show details

3Preventing Drunk Driving

Drunk driving is an excellent example of both the need and the opportunity for prevention to be comprehensive. Clearly, laws against drunk driving, enforced by the police and adjudicated by the courts, must play a leading role in the effort to keep people from driving while drunk. But legal action alone cannot solve the problem. Many other strategies also have the potential to significantly reduce drunk driving. Together with the law, these strategies can have a major effect.

There can be no question that alcohol is a major contributor to the problem of traffic safety in the United States. In about half of the 44,000 fatalities caused by traffic accidents in 1984, the drivers or other people killed in the accident had alcohol in their blood (see Figure 3-1). But this statistic can be misleading. It does not mean that if no one ever drove after drinking, highway fatalities would be cut in half. As David Reed of Harvard University points out, "Drinking-driving countermeasures can be legitimate and useful government actions, but . . . even if such countermeasures were perfectly successful, the savings in lives, injuries, and property loss would be less than widely quoted figures would lead one to believe."

Figure 3.1. Traffic deaths occur more often in the evening and nighttime hours, when visibility is poor and drivers tend to be tired.

Figure 3.1

Traffic deaths occur more often in the evening and nighttime hours, when visibility is poor and drivers tend to be tired. Alcohol-related traffic fatalities are nearly twice as numerous on Friday and Saturday nights as on other nights, and they tend to (more...)

The reason, explains Reed, is that the presence of alcohol in an accident does not always mean that alcohol caused the accident. In many accidents that kill people who have been drinking, the alcohol plays a minor or insignificant role. Roadside testing by researchers has shown that an average of 10 to 20 percent of all drivers on the road have measurable levels of alcohol in their blood. It is inevitable that some of these people will be involved in fatal accidents, even if their drinking is not to blame.

Using several epidemiological studies of drunk driving, Reed has calculated a more accurate estimate of the number of deaths that could be prevented if no one ever drove after drinking. These studies compared the blood alcohol levels of drivers involved in accidents with the blood alcohol levels of drivers not involved in accidents (this latter control group was randomly selected at times and places similar to those at which the accidents occurred). The data show that 24 percent of the fatalities would not have occurred if the drivers had not been drinking. Similar calculations give average estimates of 12 percent for the number of disabling injuries that would be prevented and 6 percent for the amount of preventable property damage. Of course, these figures are only estimates. Several factors that could not be included in the calculations could force these percentages higher or lower, and the data are far from perfect.

Nevertheless, these findings suggest that the number of theoretically preventable deaths, while not the 50 percent often cited, is still high. Nationwide, a 24 percent decrease in fatalities would mean that over 10,000 of the nearly 45,000 people killed annually in traffic accidents in recent years would not have died. Similarly, the number of theoretically preventable disabling injuries (the most ambiguous category) is between 150,000 and 300,000 per year, Reed estimates, and the property damage that could be prevented is over $1 billion. These figures indicate what might be possible. The question then becomes, how can the United States move toward these goals?

Do More Arrests Have an Effect?

The law in the United States (and throughout the world) clearly declares that people should not drive while drunk. Generally, legal codes specify a blood alcohol content (BAC) of between 0.08 and 0.10 percent, past which a person is legally intoxicated. Almost everyone agrees that drunk driving is reckless, therefore dangerous, and therefore wrong. Here, then, is a case where the law reinforces widely held public opinions.

The effectiveness of these laws, however, must be open to question. For every arrest made for driving while intoxicated (DWI), an estimated 500 to 2,000 drunk driving incidents go unpenalized, although more arrests are made for drunk driving in America than for any other offense and significant sums are spent on enforcement. Even doubling or quadrupling the number of arrests would leave the chance of arrest extremely small. With the possibility of getting caught so slim, it may seem that people would shrug off an effort by police to make more arrests.

Surprisingly, several studies show that this is not the case. An increased risk of arrest can significantly reduce drunk driving. The classic example is the British Road Safety Act of 1967. This act defined driving with a blood alcohol content of 0.08 to be an offense. The BAC was to be determined by an "Alcotest" breathalyzer device, one million of which were purchased by the British government. Police asked drivers to submit to the test given a reasonable cause, such as a road accident, a moving violation, or erratic driving. If the driver refused, illegal intoxication was assumed. Judges had no discretion in sentencing. The first offense resulted in a mandatory one-year suspension of a driver's license.

The Road Safety Act had a dramatic impact on Britain's drivers. In the three months after it took effect, traffic fatalities dropped 23 percent in Britain. In the first year of the act, the percentage of drivers killed who were legally drunk dropped from 27 percent to 17 percent.

These general trends mask several specific changes in British drinking practices. Research showed that the act did not significantly change the amount people in Britain drank. Rather, the act seems to have affected a very narrow slice of behavior—the custom of driving to and from pubs, especially on weekend nights. After the act took effect, many regular customers took to walking to pubs. Pub owners raised a considerable outcry, and a number of less conveniently located pubs closed.

Unfortunately, the successes of the act were relatively short-lived. Within a few years, traffic fatalities again began to climb. By 1973 the percentage of drivers killed who were drunk was back to its pre-1967 level. By 1975, for reasons still unknown, this percentage had risen to 36 percent, considerably above what it was before the act.

This evaporation of progress is a common feature of efforts to increase the risk of arrest. The usual explanation for it is that drivers eventually realize that the chances of arrest and punishment are not all that high. "People lose interest," says Charles Crawford, vice-president of the Ernest and Julio Gallo Winery. "The police lose interest, the judges have no more room to throw people in jail, and they start to forget about it." In the case of the British Road Safety Act, much of its initial effectiveness seems to have come from the breathalyzer, which had never been used in Britain before. The British expected the Alcotest to revolutionize the workings of the court on drunk driving cases. A scientific mechanism would replace the old system of patrols and trials. In fact, the breathalyzer had no such effect. Well-publicized cases soon established narrow limits to its authority. Standards for its use took several years to develop, and British police used it less frequently than did police in other countries. As the respect for and fear of the Alcotest declined, so did the effectiveness of the act.

Several drunk driving programs in the United States have produced results similar to those of the British Road Safety Act. In the 1970s the Department of Transportation funded 35 locally organized and managed Alcohol Safety Action Projects in various parts of the country. Each project sought in its own way to combine an increased risk of arrest, more effective trial and rehabilitation procedures, and public education to reduce the number of accidents caused by drunk driving. By increasing surveillance, targeting patrols for specific times and places, and motivating police to make arrests, many of the jurisdictions involved were able to double and triple the number of DWI arrests.

The studies that attempted to evaluate these local projects suffered from serious methodological flaws, including noncomparable sites, inadequate controls, and a premature expansion of the program. But in their final report, the projects' national evaluators found that 12 of the 35 had produced a discernible effect on nighttime auto fatalities—a good indicator of drunk driving. These 12 projects reduced fatalities an average of 30 percent over three years, which is broadly comparable to the 23 percent reduction in fatalities noted in the British program. Independent researchers, however, have concluded that the positive effects were much smaller.

The overall conclusion that can be drawn from the various drunk driving studies is that an increased risk of arrest does deter drunk driving. The National Research Council panel on alcohol abuse concludes that "some moderately persuasive evidence exists suggesting that effectively enforced drunken driving laws will deter drunken driving and reduce accidents and fatalities associated with it." Increased police surveillance is especially important at night, when most alcohol-induced traffic fatalities occur. Moreover, recent studies have shown that the speed with which drunk driving cases are decided in court can substantially influence the effectiveness of new drunk driving laws. However, other research questions remain to be answered to determine how best to reinforce the ongoing shift of attitudes toward drunk driving.

Roadblocks are a particularly controversial method used by police forces to increase their surveillance of drivers and to deter drunk driving


Roadblocks are a particularly controversial method used by police forces to increase their surveillance of drivers and to deter drunk driving.

Finally, increasing the risk of arrest is apt to be costly. For example, the Alcohol Safety Action Projects cost $88 million, not counting the costs of state and local enforcement, the expense of treatment programs borne by those arrested, and the social costs of increased police surveillance. At the most these projects saved 563 lives, for an average minimum cost of $156,000 per life saved. Many other traffic safety improvements have the potential to save lives more cost-effectively, according to the Department of Transportation, though they may not be able to save as many lives as increased enforcement of drunk driving laws.

Do Tougher Penalties Have an Effect?

There may be another way besides increased enforcement to keep people from driving while drunk. If the penalties imposed by courts and juries for drunk driving are severe, people may think twice about taking to the road when intoxicated. This alternative has the potential to be less costly than increased police surveillance, except for the drunk drivers caught, and would also concentrate the burden of stricter laws on drunk drivers rather than on all drivers.

The prime example of harsh penalties for drunk driving is found in the Scandinavian countries. There a first DWI offense commonly results in imprisonment, fines of up to 10 percent of a person's after-tax income, or license suspensions exceeding one year. Anecdotal evidence indicates that these tough penalties are effective deterrents, but social science research has been unable to uncover any hard proof.

Research has also shown that efforts to impose tougher penalties in America have not had much effect. In part, this seems to be caused by people's belief that "it can't happen to me." "After all," Reed observes, "those who currently drive drunk are not deterred by the small risk of a very severe penalty—accidental death."

Even when a drunk driver is brought to trial, judges, juries, and even police and prosecutors are often reluctant to impose tough penalties on DWI offenders. "Many people in our society do not view driving after drinking as deviant behavior," observes Reed. "If the general feeling of the public is, 'There but for the grace of God go I,' it is doubtful that severe penalties will be applied often even if they are authorized by law." However, the recent tendency of state legislatures to toughen drunk driving laws may indicate that these attitudes are changing.

The reluctance to impose harsh penalties may also stem from confusion over the nature of the offense. Mass media ads may have caused part of the problem. Some ads have suggested that any level of drinking is dangerous when combined with driving. If this were true, 75 percent of the population would have broken the law, since this is the proportion of people who in one national survey admit to having driven after drinking. If people feel they have broken the law themselves, they are inclined to judge others leniently.

In fact, the offense is drunken driving. Many people who drink and drive are not legally intoxicated, though their driving may be impaired. If these people knew how much a person had to drink to be convicted, they might be more willing to convict others of the crime. To be considered intoxicated in most states, a person who has not recently eaten typically has to have four to five drinks within an hour (although this amount varies greatly for different people). A typical BAC for a DWI offender who is brought to trial is 0.15 percent, which would require a small person to consume six to seven drinks in an hour on an empty stomach. Most Americans have probably never driven with this much alcohol in their blood.

Finally, tougher penalties for drunk driving bring their own costs, in addition to the costs imposed on the people who are caught. The length of trials and number of appeals are both likely to rise, further burdening an overtaxed court system. If drunk drivers are to be given jail terms, the expense of their imprisonment also has to be taken into account.

Despite such drawbacks, it is clear that police surveillance and appropriate penalties must be a component of society's effort to deal with drunk driving, and the use of these legal sanctions has been increasing in recent years. As the panel concludes, "At a minimum, [drunk driving laws] help sustain a widely shared disapprobation of drunken driving. They also provide an opportunity to attack a given drinking practice more aggressively if the society is willing to commit the resources, publicity, and attention necessary to make deterrence a social phenomenon rather than an abstract concept."

As noted at the beginning of this chapter, however, legal sanctions are not the sole answer to the problem of drunk driving. Many other preventive measures can also keep people from driving when drunk. The remaining chapters in this book describe these measures in detail and present the evidence for their effectiveness. The rest of this chapter outlines the main features of these measures, noting in particular their relevance to drunk driving.

Price and Availability of Alcohol

As described in Chapter 4, research has shown that higher prices for alcohol can significantly reduce the amount that people drink. Price-induced decreases in consumption have in turn been linked to declines in the incidence of drunk driving and cirrhosis of the liver. For the past three decades, the price of alcohol has been falling with respect to the price of other goods. A substantial part of this decline is due to federal and state taxes on alcohol not having kept up with inflation. Thus, the government may be able to reduce drunk driving by raising its taxes on alcohol.

It is difficult to quantify exactly how much less drunk driving would occur if taxes on alcohol were to rise. There are also economic and social costs associated with raising alcohol taxes. Nevertheless, this is a good example of how changes in general drinking practices can influence drunk driving.

It may also be possible to reduce drunk driving through specific steps affecting the availability of alcohol. Since World War II, restrictions on alcohol sales have gradually been weakening. Alcoholic beverages have been sold in more and more places, those places have been open longer hours, and minimum drinking ages in many states have gone down (although recently they have begun to go back up). Evidence from the United States that a greater number of outlets selling alcohol causes more drinking is still inconclusive. But several studies have indicated that a lower minimum drinking age does lead to greater accident and fatality rates among young people who have been drinking (Chapter 6). As the panel writes, "There is reasonable evidence that prohibition for youths does have some effect on their drinking and in particular that the choice of a minimum drinking age has a small but consistently exacerbating effect on the auto accident and fatality rates."

Another way to change the availability of alcohol is to have the people who serve alcohol, whether bartenders or private hosts, see to it that their customers or guests do not have too much to drink and then try to drive home (Chapter 5). In over half the states in the nation, "dramshop" laws impose this responsibility on commercial servers by making them liable for the damage done by underage or "obviously intoxicated" patrons to whom they serve alcoholic beverages. These laws are not as effective as they might be, however, because of the vagueness of the term "obviously intoxicated" and because they offer little guidance to servers on how to avoid liability.

In recent years, interest has been building in ways to make these laws more effective. One suggestion has been to broaden these laws to recognize a server's overall level of responsibility. If servers had standards of practice to follow in their business, courts or legislators could absolve servers who followed those standards from the liability for damage caused by patrons who drive drunk despite the server's efforts.

Educational Campaigns

Another approach to preventing drunk driving is through educational campaigns employing the mass media or local organizations such as hospitals, churches, and schools. These campaigns enjoy considerable prestige in the United States and have the potential to reach millions of people. As discussed in Chapter 7, however, evidence for their effectiveness remains scanty. People already know that drunk driving is dangerous and agree that the police and courts should move effectively to deal with it. Moreover, it is unlikely that educational campaigns will be powerful enough to fundamentally alter a person's beliefs about drinking, which are set by the entire social environment, including peer groups and family.

But there is one kind of educational campaign that holds more promise. This approach, which has been tried less often, is to teach people ways to avoid driving when dangerously or illegally drunk. It might include personal rules of thumb for knowing how much alcohol one can drink before reaching a certain BAC level, self-administered sobriety tests, or alternatives to driving when one has had too much to drink.

Of course, such information would have to exist for it to be disseminated, and increased research is needed on such matters. But even where usable findings are available, a serious problem remains. Mass media campaigns invariably shy away from any suggestion that people might drive after drinking, whether that drinking results in drunkenness or not. To hint that people might drive after drinking even though they are not legally drunk might be seen as encouraging this behavior. For example, writes Reed, "It is known that drowsiness, one of the obvious effects of drinking, impairs driving ability, yet public information and education campaigns from government and private sources consistently omit such suggestions as taking caffeine, driving with the windows open, or playing the radio when driving after drinking (although it is frequently and accurately pointed out that coffee does not reverse the intoxicating effects of alcohol). Presumably, such suggestions are omitted because they could be perceived as encouraging drunk driving by lowering its expected costs." This problem of possibly encouraging driving after drinking will surface again in the section below on reducing environmental risk.

If an educational campaign about drunk driving were instituted, certain kinds of media could be especially effective. Charles Crawford suggests putting several pages on the effects of alcohol in driver's license handbooks, which are among the most widely read booklets in America. "If every driver's handbook had a few pages, not on punitive laws but on what causes drunk driving and what constitutes social responsibility, I think it would mean a lot," he says.

Changing the Environment

Laws, server intervention, and mass media campaigns are designed to reduce the amount of drunk driving and hence the number of accidents caused by it. But it may also be possible to reduce the risk associated with drunk driving, regardless of how often people do it.

As discussed in Chapter 8, the most efficient physical devices now available to make driving safer are passive restraints, including automatic seat belts and air bags. These devices would be more effective for drunk drivers than for sober drivers, because studies show that drunk drivers involved in accidents are less likely to use conventional seat belts than are all drivers involved in accidents. Similarly, changes in road designs to make roads less confusing or distracting would help drunk drivers even more than sober drivers, since the ability to divide attention among tasks is one of the first capacities to diminish when people drink.

Another possibility is to equip cars with devices that detect an intoxicated driver and keep the car from starting or make it very conspicuous, say, by flashing its lights or honking the horn. Several such devices have been suggested. One is an analyzer that would sniff the air around a driver's head for any trace of alcohol. Another would detect errors characteristic of drinking, such as oversteering. There are also various kinds of skills testers, such as one that requires drivers to punch random numbers into a keyboard.

Of course, drivers could disconnect any such device or have someone else take the test for them. Even so, these devices could have the important effect. They could remind a driver and anyone else whose aid was enlisted that he or she was about to do a dangerous thing. The general public would probably object to the inconvenience, annoyance, and cost of having such devices in all cars. But they could be installed in the cars of select groups, such as people who have been arrested for drunk driving before.


To deal effectively with drunk driving, society must approach the problem from many different directions simultaneously. Beefed-up surveillance and tougher penalties for drunk drivers are two approaches that must be part of the solution. Drunk drivers kill and injure enough innocent third parties to warrant legal intervention, and Americans generally agree that drunk drivers should be arrested and punished.

At the same time, there are many other preventive options that should not be overlooked in an effort to get tough with drunk drivers. Higher taxes on alcohol, changes in the drinking age, responsible oversight by servers, educational campaigns, safer cars and highways, and steps to deal with repeat offenders all have at least a theoretical capability to reduce drunk driving. As we will see in the remaining chapters of this book, there are advantages and disadvantages to each of these steps, and the evidence for their effectiveness is not always conclusive. But as part of a broad, comprehensive program of prevention, they have the potential to make a significant and lasting difference.

Copyright © 1985 by the National Academy of Sciences.
Bookshelf ID: NBK217455


Recent Activity

Your browsing activity is empty.

Activity recording is turned off.

Turn recording back on

See more...