Driving Under the Influence (DUI)/ 
Driving While Intoxicated (DWI) and other State Laws

DUI/DWI Laws
Identifying Alcohol Impairment
Key State Laws Enacted to Prevent Impaired Driving
BAC-Related Data by State
Facts about DUI/DWI laws

Driving Under the Influence (DUI)/Driving While Intoxicated (DWI) Laws

The terms “Driving under the influence” (DUI) and “Driving while intoxicated” (DWI) refer to state laws that make it illegal to drive with a certain blood alcohol concentration (BAC)—the amount of alcohol found in an individual’s blood. The terms are often used interchangeably to mean driving while impaired by alcohol or other drugs.

Identifying Alcohol Impairment

Presence of alcohol is determined by measuring a person’s BAC. This process is usually conducted using a breathalyzer test. As an individual’s BAC increases, his/her mental efficiency decreases. Definite impairment beings in the range of .03 to just below .10. (A BAC level of .10 means that alcohol makes up one-tenth of one percent of the person's blood.)

Key State Laws Enacted to Prevent Impaired Driving

Strong, consistently enforced laws are critical to the success of impaired driving prevention and deterrence efforts. Research indicates that the different types of laws summarized below help reduce the incidence of impaired driving.

Illegal Per Se Laws make it illegal in and of itself to drive with a BAC measured at or above an established level. Forty-nine states have established per se laws (Massachusetts is the exception). As of December 2001, 29 states, Washington DC and Puerto Rico had .08 as the established BAC level, while 21 states remained at the .10 level. In other words, it is illegal to drive a motor vehicle if a driver has a BAC level of .08 or .10, depending on the state. Research indicates that virtually all drivers show impairment in driving ability at .08 BAC, and the majority exhibit serious deterioration. Virtually all highway safety organizations and transportation safety agencies support .08 BAC, and in October 2000, Congress passed .08 BAC as the national standard for impaired driving regulations. States that do not adopt .08 BAC by a certain date will be denied a portion of their highway construction funds.

Dram Shop/Social Host Liability Laws state that a person who serves alcoholic beverages to intoxicated individuals may be liable for the damages caused by such individuals. In some states, a server may also be liable for injuries sustained by intoxicated individuals.

Minimum Legal Drinking Age (MLDA) Laws make it illegal for individuals younger than 21 to purchase, possess or consume alcoholic beverages or to misrepresent their age to obtain such beverages.

Zero Tolerance Laws make it illegal for drivers younger than 21 to drive with any measurable amount of alcohol in their system—regardless of the BAC limit for drivers over 21. Many states set the limit for drivers under 21 at .02 BAC or below to help reduce legal challenges based on claims that mouthwash, gum or cold medicine can be responsible for a positive but very low BAC measurement. However, there is no evidence that such substances affect the standard breath analysis tests when conducted properly or that other challenges to the accuracy of alcohol detection equipment are valid. By late 1999, all states plus the District of Columbia had zero tolerance laws for youth.

Open Container Laws prohibit the possession of any open alcoholic beverage container and the consumption of any alcoholic beverage in the passenger area of a motor vehicle. In 1998, the Federal government took steps to encourage states to enact open container laws by passing the Transportation Equity Act for the 21^st Century (TEA-21), which required states to enact open container laws by October 1, 2000 or lose a portion of their Federal-aid highway construction funds. To avoid having their funds transferred to other safety activities, states must certify that they comply with Federal requirements and that their open container law is in effect and being enforced. By October 1, 2000, 30 states and the District of Columbia had open container laws in effect.

Administrative License Revocation (ALR) laws involve license suspension or revocation following conviction for impaired driving. ALR laws give state officials the authority to immediately suspend the license of any driver who fails or refuses to take a BAC test. Some states may restore driving privileges on a limited basis due to demonstrated hardship, as determined by the courts. Depending on the state, suspensions range from seven days to six months for first-time offenders and longer for repeat offenders. As of late 2000, 40 states and the District of Columbia had ALR laws in effect.

Vehicle and License Plate Sanctions affect the vehicles or license plates DUI/DWI offenders. Actions states can take include the following. Check with your State Department of Transportation to determine the exact nature of laws in your jurisdiction.

• Vehicle impoundment
• Suspension of vehicle registration
• Vehicle confiscation
• Vehicle forfeiture (sale of an offender’s vehicle)
• Vehicle immobilization (bars offender from using his or her car)
• Special license plates or plate markings (permit use of a vehicle by family members of convicted DUI/DWI offenders)
• Ignition interlock (device that measures alcohol concentration in the breath and is attached to a vehicle's ignition system; a driver must have a BAC below a certain level in order to start the vehicle)

BAC-Related Data by State

*A multiple offender's vehicle may be seized and disposed.
**Effective 09/30/03

Facts about DUI/DWI Laws

In the US, BAC limits for DUI/DWI Laws are determined by individual states. The limit of .10 BAC used in some states is the highest in the industrial world.¹

A 1999 report by the General Accounting Office (GAO) stated that although the impact of .08 BAC laws is not conclusive, there are “strong indications that .08 BAC laws, in combination with other drunk driving laws (particularly license revocation laws), sustained public education and information efforts, and vigorous and consistent enforcement, can save lives.”²

A multi-state study found that .08 BAC laws correlated positively with reductions in alcohol-related fatalities, alone or in conjunction with Administrative License Revocation (ALR) laws, in seven of 11 states. In five of these seven states (Vermont, Kansas, North Carolina, Florida and New Mexico), implementation of the law itself correlated positively with lower rates of alcohol-related fatalities. ³

In 1998, more than 80 percent of drivers involved in fatal crashes who tested positive for alcohol had BAC levels exceeding .08. ⁴

Research indicates that .08 BAC laws reduce not only the incidence of impaired driving at lower BACs, but also the incidence of impaired driving at higher BACs (i.e, more than .10). ⁵

An average male weighing 170 pounds would have to consume more than four beers within one hour on an empty stomach to reach a .08 BAC level. ⁶

Virtually all drivers’ critical driving skills, such as braking, steering and lane changing, are impaired at .08 BAC. The rate of impaired performance is as high as 70 percent. ⁷

Federal law requires that states have laws that target repeat intoxicated drivers. Four categories of laws impact these individuals: licensing sanctions (ALR laws); vehicle sanctions (vehicle impoundment); required alcohol assessment and treatment; and mandatory sentencing. ⁸

ALR laws do not replace criminal prosecution and their constitutionality has been consistently upheld when challenged. All state appellate courts that have considered this issue have upheld ALR as a constitutional means of protecting the public from impaired drivers. ⁹

Results of a 1996 study indicate that ALR laws do not significantly impact an offender’s job or income. The study compared three ALR laws states with one state that used other sanctions and found no difference regarding offender employment or income. In both ALR and non-ALR laws states, 94 percent of offenders who were employed at the time of their arrest were still working one month later. Four percent were unemployed and two percent were in school. License revocations as long as 90 days did not lead to loss of job or income. ¹⁰

All states and the District of Columbia have a minimum drinking age of 21. The National Highway Transportation Safety Administration (NHTSA) estimates that these laws have reduced traffic fatalities involving drivers ages 18-20 by 13 percent and have saved as many as 23,043 lives since 1975. In 2000, the number of estimated lives saved by minimum drinking age laws was 922. ¹¹

Endnotes:

¹ National Highway Transportation Safety Administration. (April 2001). Setting Limits, Saving Lives: The Case for.08 BAC Laws. Washington, DC: US Department of Transportation. ² Ibid.
³ Ibid.
⁴ National Highway Transportation Safety Administration. (2001). State Legislative Fact Sheet, .08 BAC Illegal Per Se Level. Washington, DC: US Department of Transportation.
⁵ National Highway Transportation Safety Administration. (January 2001). State Legislative Fact Sheet, .08 BAC Illegal Per Se Level, Point-Counterpoint. Washington, DC: US Department of Transportation.
⁶ Supra Note 4.
⁷ Insurance Institute for Highway Safety, Highway Loss Data Institute. (2000). DUI/DWI Laws as of October 2000.
⁸ National Highway Transportation Safety Administration. (2001). State Legislative Fact Sheets, Repeat Intoxicated Driver Laws. Washington, DC: US Department of Transportation.
⁹ National Highway Transportation Safety Administration. (2001). Administrative License Revocation (or Suspension), Key Facts. Washington, DC: US Department of Transportation.
¹⁰ Ibid.
¹¹ National Highway Transportation Safety Administration. (2001). Traffic Safety Facts 2000, Alcohol. Washington, DC: US Department of Transportation