Driving While Intoxicated (DWI) is the offense of driving, operating, or being in control of a vehicle while impaired by alcohol or drugs (including recreational drugs and those prescribed by physicians), to a level that renders the driver incapable of operating a motor vehicle safely.
Also called driving while intoxicated (DWI), drunk driving, operating while intoxicated (OWI), operating [a] vehicle under the influence of alcohol or drugs (OVI) in Ohio, drink-driving (UK/Ireland), or impaired driving (Canada).
The name of the offense varies from jurisdiction to jurisdiction and from legal to colloquial terminology. In the United States, the specific criminal offense is usually called driving under the influence, but in some states "driving while intoxicated" (DWI), "operating while impaired" (OWI) or "operating while ability impaired", "operating a vehicle under the influence" (OVI), etc. Such laws may also apply to boating or piloting aircraft. Vehicles can include farm machinery and horse-drawn carriages, along with bicycles. Other commonly used terms to describe these offenses include drinking and driving, drunk driving, drunken driving, impaired driving, operating under the influence, or "over the prescribed limit".
The criminal offense may not involve actual driving of the vehicle, but rather may broadly include being physically "in control" of a car while intoxicated, even if the person charged is not in the act of driving. For example, a person found in the driver's seat of a car while intoxicated and holding the car keys, even while parked, may be charged with DUI, because he or she is in control of the vehicle.
In construing the terms DUI, DWI, OWI, and OVI, some states therefore make it illegal to drive a motor vehicle while under the influence or driving while intoxicated while others indicate that it is illegal to operate a motor vehicle. There is a split of authority across the U.S. regarding this issue. Some states permit enforcement of DUI/DWI and OWI/OVI statutes based on "operation and control" of a vehicle, while others require actual "driving". "The distinction between these two terms is material, for it is generally held that the word 'drive,' as used in statutes of this kind, usually denotes movement of the vehicle in some direction, whereas the word 'operate' has a broader meaning so as to include not only the motion of the vehicle but also acts which engage the machinery of the vehicle that, alone or in sequence, will set in motion the motive power of the vehicle." (State v. Graves (1977) 269 S.C. 356 [237 S.E.2d 584, 586–588, 586. fn. 8].)
In some countries (including Australia and many jurisdictions throughout the United States), a person can be charged with a criminal offense for riding a bicycle, skateboard, or horse while intoxicated or under the influence of alcohol.