Lower is even better.

Reducing blood alcohol concentration (BAC) in drivers reduces drunk driving fatalities. When states lowered their BAC limits from. 10 to .08, alcohol-related injuries and fatalities dropped by an average of 7 percent to 8 percent, according to a study published in the Journal of Safety Research and sponsored by MADD of Canada.

In countries where the drunk driving limit is .05 BAC, the study found even greater reductions-in alcohol-related deaths. Seventeen countries--Australia, Austria, Belgium, Bulgaria, Croatia, Denmark, Finland, France, Germany, Greece, Israel, Italy, the Netherlands, Portugal, South Africa, Spain and Turkey--have lowered their limits to .05. Poland's standard is .03, and Norway, Russia and Sweden have adopted a BAC limit of .02.

All U.S. states have adopted a BAC limit of .02 or less for drivers aged 21 and under, in compliance with federal "zero tolerance" mandates. The study found that these laws have been very effective in reducing alcohol-related traffic deaths among young drivers.

James Fell, senior program director at the Pacific Institute for Research and Evaluation (PIRE) and one of the co-authors of the study said that "There is clear, strong evidence that lowering the BAC limit is effective. Whether it's lowered from. 10 to .08 or from .08 to .05, the number of deaths and injuries from drunk driving will be...