With drunken driving still a national problem that accounts for one-third of all traffic deaths, federal safety regulators Tuesday called on states to take a dramatic step: Lower the legal limit for drivers' blood-alcohol content to the level of a single dry martini.

The National Transportation Safety Board wants state legislatures to drop the measure from the current blood-alcohol level of 0.08 to 0.05, about that caused by a dry martini or two beers in a 160-pound person, according to a University of Oklahoma calculator.

"The research clearly shows that drivers with a BAC above 0.05 are impaired and at a significantly greater risk of being involved in a crash where someone is killed or injured," NTSB Chairwoman Deborah Hersman said. "Our goal is to get to zero deaths, because each alcohol-impaired death is preventable."

The NTSB has no authority to impose its recommendations but provides an influential voice in the setting of safety standards. The board's proposal got an immediate positive response from an organization of state highway safety officials.

"NTSB's action raises the visibility of drunk driving, and we will consider their recommendations," said Jonathan Adkins of the Governors Highway Safety Association, while underscoring that the group continued to support the 0.08 level.

Advocates for the beer and liquor industry reacted negatively to the recommendation.

"While obviously the NTSB doesn't make policy, states take their recommendations very seriously," said Sarah Longwell of the American Beverage Institute, which lobbies for the industry on the state and national level.

She denounced the recommendation as "terrible."

"Between .05 and .08 is not where fatalities are occurring," Longwell said. "This is like, people are driving through an intersection at 90 miles an hour and so you drop the speed limit from 35 to 25. It doesn't make any sense."

Longwell said the average blood-alcohol level in alcohol-related traffic fatalities was .16.

Almost 10,000 people are killed - and 173,000 injured - each year in drunken-driving crashes, the NTSB said. About 30 percent of all deaths continue to be alcohol-related.