Driving under the influence

Driving under the influence (DUI) or Driving while intoxicated (DWI) is the crime of driving a motor vehicle while impaired by alcohol or other drugs (including those prescribed by physicians), to a level that renders the driver incapable of operating a motor vehicle safely. The name of the offense varies from jurisdiction to jurisdiction and from legal to colloquial terminology. Other terms include: drink-driving, drunk driving, drunken driving, impaired driving, operating under the influence, drinking and driving, over the prescribed limit (OPL). People who receive multiple DUIs are often struggling with alcoholism or alcohol dependence.

With alcohol, a drunk driver's level of intoxication is typically determined by a measurement of blood alcohol content or BAC. A BAC measurement in excess of a specific threshold level, such as 0.05% or 0.08%, defines the criminal offense with no need to prove impairment. In some jurisdictions, there is an aggravated category of the offense at a higher BAC level, such as 0.12%.

Drunk driving in the United States

Drunk driving is the act of operating or driving a motor vehicle while under the influence of alcohol or drugs to the degree that mental and motor skills are impaired. It is illegal in all jurisdictions within the United States, though enforcement varies widely between and within states/territories.

The specific criminal offense is usually called driving under the influence (DUI), and in some states 'driving while intoxicated' (DWI), 'operating while impaired' (OWI), or 'operating a vehicle under the influence' (OVI). Such laws may also apply to boating or piloting aircraft. Vehicles can include farm machinery and horse-drawn carriages.

In the United States the National Highway Traffic Safety Administration (NHTSA) estimates that 17,941 people died in 2006 in alcohol-related collisions, representing 40% of total traffic deaths in the US. NHTSA states 275,000 were injured in alcohol-related accidents in 2003. The Bureau of Justice Statistics estimated that in 1996 local law enforcement agencies made 1,467,300 arrests nationwide for driving under the influence of alcohol, 1 out of every 10 arrests for all crimes in the U.S., compared to 1.9 million such arrests during the peak year in 1983, accounting for 1 out of every 80 licensed drivers in the U.S.