The review was done by James Fell and Robert Voas from the Pacific Institute for Research and Evaluation, a nonprofit group in Calverton, Md.

Fell and Voas report that when the United States lowered the legal BAC limit from .10 to the current .08, alcohol-related crashes and injuries dropped by an average of 7 to 8 percent. In countries where the limit was lowered to .05 BAC, additional reductions took place.

BAC refers to a measurable amount of alcohol in human blood. This amount is measured in grams per deciliter (g/dl). A positive BAC--.01 g/dl or higher--indicates that someone has consumed alcohol.

"There is clear, strong evidence that lowering the BAC limit is effective," said Fell, who has studied impaired driving for 30 years. "Whether it's lowered from .10 to .08 or from .08 to .05, the number of deaths and injuries from drunk drinking will be reduced and lives will be saved."

The review by Fell and Voas, which is the latest summary of relevant research, makes several points to support BAC limits lower than .08 percent:

• In laboratory experiments, most people are significantly impaired at a BAC of .05. This level of intoxication reduces coordination and response to emergency driving situations. It also induces drowsiness and interferes with the ability to steer and track moving objects.
• Compared to drivers who haven't been drinking, drivers with a BAC of .05 to .07 are four to 10 times more likely to be involved in a fatal crash.
• All states already prohibit truck drivers from having more than a .04 BAC.
• There is public support for lower BAC limits. According to surveys, a majority of Americans believe that no one should drive after having two or three drinks.
• For most people, that's equivalent to a BAC of about .05.
• There is professional support for lower limits. Organizations that favor BAC limits of .05 or less include the World Medical Association, the American and British Medical Associations, the European Commission, the European Transport Safety Council, the World Health Organization, and the American College of Emergency Physicians.
• The movement toward lower BAC limits has strong international support. Nations with a .05 limit include Australia, Austria, Belgium, Bulgaria, Croatia, Denmark, Finland, France, Germany, Greece, Israel, Italy, the Netherlands, Portugal, South Africa, Spain and Turkey. Norway and Sweden have a .02 BAC limit.

"There is a worldwide trend to totally separate drinking and driving," says Steve Simon, a clinical professor at the University of Minnesota Law School and director of the DWI Task Force for the Minnesota Criminal Justice System. "The research shows that any amount of alcohol in a driver's system increases the risk of being involved in a crash."

Simon believes that the movement to reduce legal BAC limits to .05 in the United States will be "a very long, slow process"--one that could take 10 to 20 years. Even so, he says, this movement will succeed.

Impaired driving affects one in three Americans during their lifetime. In 2004, 16,694 people died in alcohol-related motor vehicle crashes, accounting for 39 percent of all traffic-related deaths in the United States.

The review by Fell and Voas was published in the Journal of Safety Research, volume 37, issue 3, pp. 233-243. It lends new support for National Drunk and Drugged Driving Prevention Month, which is in December. The primary message of the effort is "Friends Don't Let Friends Drive Drunk--Designate a Sober Driver." More information about this event is available from the Centers for Disease Control.

--Published November 27, 2006