The lower threshold was one of a series of recommendations aimed at reducing drunken driving made by the National Transportation Safety Board's staff in a report presented at a meeting of the board.
New approaches are needed to combat drunken driving, which claims the lives of more than a third of the people killed each year on U.S highways - a level of carnage that that has remained stubbornly consistent for the past decade and a half, the board said.
"Our goal is to get to zero deaths because each alcohol-impaired death is preventable," NTSB Chairman Deborah Hersman said. "Alcohol-impaired deaths are not accidents, they are crimes. They can and should be prevented. The tools exist. What is needed is the will."
Dramatic progress was made in the 1980s through the mid-1990s after the minimum drinking age was raised to 21 and the legally-allowable maximum level of drivers' blood alcohol content was lowered to .08, the report said. Today, drunken driving claims about 10,000 lives a year, down from over 18,000 in 1982. At that time, alcohol-related fatalities accounted for about 40 percent of highway deaths.
But progress in cutting the rate further has largely stagnated, and board members have called for a fresh approach.
Technology may be part of the solution, and anti-drunken driving forces have talked of turning cars into a part of the solution.
In December, the board called on the National Highway Traffic Safety Administration and the auto industry to step up their research into technology for use in all vehicles that can detect whether a driver has elevated blood alcohol without the driver breathing into a tube or taking any other action. Drivers with elevated levels would be unable to start their cars.
But the technology is still years away.
A combination of approaches will be needed to effectively drive down fatalities, researchers told the board at a two-day forum on drunk driving last year.
Reducing the blood alcohol limit below .08 could save over 7,000 lives a year, the Insurance Institute for Highway Safety has estimated.
Australia saw a 12 percent decline in alcohol-related deaths as a share of overall traffic fatalities when it lowered its legal limit to .05. The limit in most of Europe is also .05, and in some countries it's as low as .02.
A woman weighing less than 120 pounds can reach .05 after just one drink. A man weighing up to 160 pounds reaches .05 after two drinks.
A recommendation made by researchers last year has been to expand the use of alcohol ignition interlock devices by drivers convicted of driving under the influence. The devices usually require a driver to breathe into a tube, much like the breathalyzers police ask suspected drunken drivers to use.
Expanded use of high visibility checkpoints by police has also been recommended.