Drunk driving is the act of driving a car or another vehicle while intoxicated. Intoxicated is defined in different ways in different situations. The classic definition of driving while intoxicated is a person who gets behind the wheel with a blood alcohol content of greater than 0.08. But it can also involve driving with lower blood alcohol content levels for special populations such as the drivers of commercial vehicles and minors. There are also several drugs that can lead a person to be impaired enough to trigger a DUI charge.