Driving under the influence of alcohol (DUI) is a major contributor to traffic crashes and fatalities, with nearly 17,000 lives lost in the United States each year due to alcohol-related crashes.
Traffic crashes are the leading cause of death for those between 4–34 years of age, and rank third overall in terms of years of life lost, after cancer and heart disease.
Over the last four decades the United States has joined the rest of the industrialized world in implementing a modern DUI enforcement system based on the well-established relationship of driving impairment to the level of alcohol in the blood. This has resulted in hundreds of specific changes in laws across the 50 U.S. states designed to deter DUI, including reductions in legal blood alcohol content (BAC) limit for driving, mandatory minimum jail and fine penalties for those convicted of DUI, administrative license revocation at the time of arrest for DUI and implementation of sobriety checkpoints.
Teen drivers are at particular risk. Although they drink and drive less often than older drivers, when they do drink and drive they are at greater risk of being involved in a crash. As a result, minimum legal drinking age, zero BAC limits and graduated drivers licensing laws which lengthen the driving learning period and limit high-risk nighttime driving until the novice driver has gained experience, have been implemented to reduce risk among drivers under age 21.