Driving Under The Influence (DUI) Definition and Legal Meaning

On this page, you'll find the legal definition and meaning of Driving Under The Influence (DUI), written in plain English, along with examples of how it is used.

What is Driving Under The Influence (DUI)?

n. “Drunk driving.” Operating a motor vehicle with a blood alcohol content that is higher than the legal limit which has been set at a level at which a person cannot safely drive. The statutes range from .08 to .10 for adults which equates to 8/100ths to one-tenth of one percent by weight of alcohol to the weights of blood. For blood tests and urine samples, this is translated into grams of alcohol per 100 milliliters of blood, or grams of alcohol per 210 liters of air for breathalyzer tests. Based on erratic driving, a combination of the use narcotics and alcohol can classify as being “under the influence.” While driving on private property such as a parking lot is not a defense, sitting in a non-moving vehicle without the ignition on, may qualify as a DUI or DWI (driving while intoxicated) misdemeanor.