Alcohol is involved in more than half of all traffic fatalities and in more than three-quarters of the fatal crashes that occur between 8 p.m. and 4 a.m. In 1989, the blood alcohol concentrations of drinking drivers involved in fatal crashes were 0.16, compared to the legal limit of 0.10 in most states. However, sobriety checkpoints that are established according to United States Supreme Court guidelines have been effective in reducing alcohol-related crashes. These checkpoints are controversial, but the decision in Michigan Department of State Police v. Setz et al concluded that checkpoints represent reasonable seizures that appropriately balance the State's interest in preventing accidents, the effectiveness of sobriety checkpoints, and the intrusion into the individual's privacy. Photographs and table.