Newswise — In every U.S. state, it is illegal for adults to drive with a blood alcohol concentration (BAC) of .08 grams per deciliter (g/dL) or greater. In 2013, the National Transportation Safety Board recommended that states lower the BAC limit for driving from .08 to .05 grams. Most industrialized nations have already enacted a .05 BAC limit. This study investigated whether lowering the BAC limit to .05 would be an effective alcohol policy in the United States.
Researchers carried out their examination in three stages. First, they conducted a meta-analysis of 37 qualifying international studies to estimate the range and distribution of effects from a reduction to .05 BAC or lower. Next, they estimated the effects of reducing the current .08 BAC limit to .05 in the United States. Lastly, they estimated specific life-saving benefits of a .03 reduction in the BAC driving limit from .08 to .05.
Results provided strong evidence in support of lowering the BAC limit to reduce alcohol-related crashes. The meta-analysis of international studies on lowering the BAC limit showed a 5.0 percent decline in non-fatal alcohol-related crashes, a 9.2 percent decline in fatal alcohol-related crashes from lowering the BAC from .10 to .08, and an 11.1 percent decline in fatal alcohol-related crashes from lowering the BAC to .05 or lower. The authors estimated that 1,790 lives would be saved each year if all U.S. states adopted a .05 BAC limit.