Summary: Most states make it illegal for someone to drive with a blood alcohol concentration (BAC) of .10--the level at which a person's blood contains 1/10th of one percent alcohol. However, 16 states have more stringent laws setting the limitation at .08 BAC. In 1998, the Clinton administration endorsed a bill that would have required all states to enact and enforce .08 BAC laws or face cuts in federal highways funds. GAO found that the evidence does not conclusively establish that .08 BAC laws, by themselves, reduce the number and the severity of alcohol-related crashes. There are, however, strong indications that .08 BAC laws, in combination with other drunk driving laws (particularly license revocation laws), sustained public education and information efforts, and vigorous and consistent enforcement can save lives. Until recently, only four published studies examined the effectiveness of BAC laws in five states, and, although the National Highway Traffic Safety Administration characterized the studies as conclusively establishing that .08 BAC laws by themselves were effective, the studies had limitations. In April 1999, three additional studies were released that were more comprehensive and showed many positive results but also fell short of providing conclusive evidence that .08 BAC laws were, by themselves, responsible for reducing alcohol-related crashes and fatalities.
