Commonly called “drunk driving,” it refers to operating a motor vehicle while one’s blood alcohol content is above the legal limit set by statute, which supposedly is the level at which a person cannot drive safely. state statutes vary as to what that level is, but it ranges from .08 to .10 for adults, which means a 8/100ths to one-tenth of one percent by weight of alcohol to the weight of blood. this is translated into grams of alcohol per 100 milliliters of blood in tests of blood or urine sample, or grams of alcohol per 210 liters of air in a “breathalizer” test. a combination of the use of alchol and narcotics can also be “under the influence” based on erratic driving. driving on private property such as a parking lot is no defense, but sitting in a non-moving vehicle without the ignition on probably is (sometimes resulting in a charge of “drunk in and about a vehicle”). this is a misdemeanor and is variously referred to as dui, driving while intoxicated (dwi), drunk driving, or a “deuce”.