It may surprise you to learn that you don't need to drink much alcohol before your ability to drive becomes impaired. For example, certain driving skills--such as steering a car while, at the same time, responding to changes in traffic--can be impaired by blood alcohol concentrations (BACs) as low as 0.02 percent. (The BAC refers to the amount of alcohol in the blood.) A 160-pound man will have a BAC of about 0.04 percent 1 hour after consuming two 12-ounce beers or two other standard drinks on an empty stomach (see page 1, What Is a Drink?). And the more alcohol you consume, the more impaired your driving skills will be. Although most States set the BAC limit for adults who drive after drinking at 0.08 to 0.10 percent, impairment of driving skills begins at much lower levels.
