Catching a few Z’s after a night of drinking does not make a sober driver. In fact, if you go to a party and get really drunk – double the legal limit or more – go home at 2 a.m. by cab, but then get up at 7 a.m. and hop in the company truck, you’ll still be above the legal limit.
Sleep has no impact on reducing a person’s blood alcohol content. While blood alcohol concentration peaks within a half-hour of the last drink, the rate by which it falls is far slower than the rate at which is rises. Weight and gender both have a part to play in the speed of a person’s dissipating BAC, but even if enough time has passed to lower it to a legal level, a person still may be impaired. Bad hangovers can also seriously hamper judgment and cognitive function.
If you plan to drink over the holidays, PLEASE leave your keys behind.