|III. The Laws
This chapter briefly describes a number of laws that apply to underage drinking and impaired driving. These include laws that apply to both adult and underage DUI offenders, laws that apply only to underage drivers, and laws designed to prevent underage drinking. Research has proven the effectiveness of a number of these laws for reducing alcohol-related crashes.
Citizen activist groups such as Mothers Against Drunk Driving (MADD), Students Against Destructive Decisions (SADD), and Remove Intoxicated Drivers (RID) have heightened public awareness about the dangers of drinking in the context of driving. These groups also have influenced public opinion about the unacceptability of underage drinking. The effectiveness of these groups in promoting legislation to prevent these behaviors has contributed to the passage of laws in all States raising the minimum legal drinking age to 21, zero tolerance laws for youth, and laws lowering blood alcohol concentration (BAC) limits for adult drivers to 0.08 in 17 States by September 1, 1999.
Laws Directed at Driving Under the Influence of Alcohol and Other Drugs
In general, laws related to impaired driving are applicable to drivers under age 21 as well as to drivers 21 and older. Zero tolerance laws are applicable specifically to drivers under age 21. Implied consent laws are related to impaired driving laws as a whole.
Driving Under the Influence (DUI) or Driving While Intoxicated (DWI) Laws
These laws make it a criminal offense to operate a motor vehicle while impaired or intoxicated by alcohol or other drugs. These laws do not require a measurement of breath- or blood-alcohol level. Rather, the offense is committed when there is evidence that the driver's behavior is caused by the influence or impairment of alcohol or other drugs. Every State has a DUI or DWI law.
Illegal Per Se Laws
These laws make it a criminal offense to operate a motor vehicle if the driver has a blood or breath alcohol concentration at or above a specific level. In most States, this level is 0.10 BAC, although a growing number of States have lowered this level to 0.08 BAC. One study, which paired the first five States to adopt a 0.08 law with five nearby States that retained the legal 0.10 limit, found that the 0.08 States experienced a 16-percent relative decline in the proportion of crashes involving fatally injured drivers whose BACs were 0.08 percent or higher. States with the 0.08 law also experienced an 18-percent relative decline in the proportion of crashes involving fatally injured drivers with BACs of 0.15 or higher (Hingson et al. 1996a). A later study paired six additional States with 0.08 laws with six comparison States. While both groups experienced declines in the proportion of drivers in fatal crashes who had BACs of 0.10 or higher, the decline in the 0.08 States was 1.5 times greater than the decline in the comparison States (Hingson et al. 1998).
Administrative Per Se Laws
These laws allow a driver licensing agency to suspend or revoke (depending on the State statute) a driver's license if the driver is found to have operated a motor vehicle at or above a specified blood- or breath-alcohol concentration. Some States also allow for the suspension or revocation of driving privileges based on motor vehicle operation with any amount of a controlled substance in the body. Under these laws, police seize the license of the driver at the time of arrest. Whether for alcohol or other drugs, this action may be taken independently of any criminal action or any sanction that may be imposed for violation of a criminal offense for impaired driving. Administrative license suspension and other administrative control strategies are discussed in Chapter 8.
Zero Tolerance Laws
These laws, often a combination of illegal per se and administrative per se laws, prohibit persons under 21 years of age from operating a motor vehicle if they have any measurable amount of alcohol in the blood or breath. Most States allow the driver licensing agency to suspend or revoke the driver's license if the driver is found to have an alcohol concentration of 0.02 or above.
The recent adoption of zero tolerance laws by all States and the District of Columbia may have contributed to the significant reduction in the proportion of underage drivers found to have BACs at or above 0.10 when tested at a national roadside survey of weekend, nighttime drivers in 1986 and 1996 (Voas et al. 1998). Likewise, the number of 15- to 20-year-old drivers involved in fatal crashes who had positive BACs declined 61 percent between 1982 and 1996, and the proportion of young drivers involved in fatal crashes who had positive BACs declined 51 percent over that time period (NHTSA 1998a).
A study of the first 12 States to implement zero tolerance laws found that, compared with 12 other States, those with the law experienced a 20-percent relative decline in the proportion of single-vehicle nighttime fatal crashesthose most likely to involve alcoholamong drivers under age 21. Furthermore, the greatest declines in fatal crashes occurred in States where underage BAC limits were set at 0.02 percent or less, while little impact was found in States that had set their BAC limits at 0.04 or 0.06 (Hingson et al. 1994). A public education campaign to raise awareness about Maryland's zero tolerance law was associated with a 44-percent decrease in the proportion of alcohol-related crashes among underage drivers in the campaign-exposed counties; a 30-percent decline was seen in the comparison counties (Blomberg 1992).
Related to the impaired driving laws are implied consent laws, which provide that a person who operates a motor vehicle implicitly consents to submit to a test for either alcohol or drug content in either blood or breath if they are arrested for any of the impaired driving offenses.
Laws Directed at Reducing Drinking Under Age 21
All States have laws that are designed to prevent underage drinking by restricting underage persons' access to alcohol. Such laws are often enforced in efforts to prevent underage DUI and zero tolerance violations.
Minimum Legal Drinking Age (MLDA) Laws
These laws make it illegal for any person who is less than 21 years old to either purchase, possess, or consume alcoholic beverages or to misrepresent their age to obtain such beverages. Every State and the District of Columbia has an MLDA law, but the exact prohibitions in these State laws vary widely. For example, some States do not prohibit the consumption of alcoholic beverages by persons under age 21. Some States allow persons under age 21 to possess alcoholic beverages in connection with employment activities. Most States allow persons under age 21 to possess and consume alcoholic beverages for religious purposes and at home.
Raising the MLDA to 21 has been accompanied by reduced alcohol consumption, traffic crashes, and related fatalities among those under age 21 (Wagenaar 1993; NIAAA 1996b). A study of 13 States found that, after the MLDA was raised to 21, the rate of single-vehicle nighttime fatal crashes fell 15 percent among drivers under 21 but only 5 percent among drivers 21 and older (O'Malley and Wagenaar 1991). NHTSA estimates that 16,513 lives were saved by the State MLDA laws between 1975 and 1996 (figure 3-1). In 1996 alone, it is estimated these laws saved 846 lives (NHTSA 1998a).
Most States have laws that allow administrative license suspension or revocation as a consequence of violating one or more of the MLDA laws. These laws, which are called "use and lose" laws, have not been formally evaluated. However, the effectiveness of these laws may be limited by infrequent enforcement.
Adult Responsibility Laws
These laws prohibit a person age 21 or older from purchasing alcoholic beverages for an underage person or from giving or furnishing such beverages to a person under age 21. Some statutes make it illegal to solicit such an act as well. This prohibition may be specifically directed at prohibiting persons age 21 and older from furnishing alcoholic beverages to youth on private property.