Driving under the influence (DUI), driving while intoxicated (DWI), drunken driving, drunk driving, operating under the influence, drinking and driving, or impaired driving is the crime of driving a motor vehicle while impaired by alcohol or other drugs including those prescribed by physicians.
In the case of 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%. In most countries, anyone who is convicted of injuring or killing someone while under the influence of alcohol or other drugs can be heavily fined in addition to being given a lengthy prison sentence. DUI and alcohol-related crashes produce an estimated $45 billion in damages every year. The first person to be arrested for drunk driving was one George Smith, a London taxi driver who ran his cab into a vehicle in 1897.