Moderate drinking does not necessarily increase a person's BAC to the level at which driving is legally prohibited, but any drinking can impair driving tasks by reducing the driver's reaction time and slowing the decision process. A driver's ability to divide attention between two or more visual stimuli can be impaired at a BAC of 0.02 percent or lower. Drivers exhibit impairment in eye movement, visual perception, reaction time, and other factors starting at a BAC of 0.05 percent. The legal BAC limits for drivers in several other countries come closer than those in the United States to restricting drivers to moderate drinking. Nonetheless, research indicates that laws enacted in the United States have reduced alcohol-related traffic deaths among both moderate drinkers and those who have high blood alcohol levels. Current United States laws that limit drivers' BAC to 0.10 and 0.08 percent have been effective in reducing alcohol-related crashes. Other effective approaches have included laws on driver's license revocation or suspension; other penalties for exceeding the BAC limits; and laws that have restricted alcohol accessibility by increasing taxes, restricting alcohol outlet density and hours of operation, maintaining State control of alcohol sales, and restricting alcohol sales to inebriated persons or persons under age 21. Increased knowledge of what represents moderate drinking and the amount of alcohol a person can reasonably consume before becoming impaired would help raise people's sense of responsibility, both as drinkers and as drivers, ultimately saving thousands of lives. Figures and 56 references