Driving under the influence (DUI) (driving while intoxicated (DWI), drunken driving, drunk driving, operating under the influence, drinking and driving, drink-driving, impaired driving) is the act of driving a motor vehicle with blood levels of alcohol in excess of a legal limit. Similar regulations cover driving or operating certain types of machinery while affected by drinking alcohol or taking other drugs. This is a criminal offense in most countries. Details of the offense depend upon the jurisdiction, and may include merely being in physical control of a motor vehicle while being under the influence of alcohol or drugs. Convictions do not necessarily involve actual driving of the vehicle.
In most jurisdictions a measurement such as a blood alcohol content in excess of a defined level, such as 0.05% or 0.08% defines the offense, with no need to prove impairment or being under the influence of alcohol. In some jurisdictions, there is an aggravated category of the offense at e.g. 0.12%. In most countries, anyone who is convicted of injuring or killing someone while under the influence of alcohol or drugs can be heavily fined, as in France, in addition to being given a lengthy prison sentence.
Many states in the U.S. have adopted truth in sentencing laws that enforce strict guidelines on sentencing, different from past practice where prison time was reduced or suspended after sentencing had been issued.
The specific criminal offense may be called, depending on the jurisdiction, driving under the influence [of alcohol or other drugs] (DUI), driving under intense influence(DUII), driving while intoxicated (DWI), “operating under the influence” (OUI) operating while intoxicated (OWI), operating a motor vehicle while intoxicated (OMVI), driving under the combined influence of alcohol and/or other drugs, driving under the influence per se or drunk in charge [of a vehicle]. Other less common acronyms includeoperating a vehicle (while) impaired (OVI), and Driving While Ability Impaired (DWAI). Many such laws apply also to boating, piloting aircraft, or cycling, possibly with different BACs than driving. In some jurisdictions there are separate charges depending on the vehicle used, such as BWI (bicycling while intoxicated), which may carry a lighter sentence.