U.S. Urges a Lower Blood-Alcohol Limit for Drunken Driving Ramin Rahimian for The New York Times A police officer in San Jose, Calif., administering a breathalyzer test in 2010. The current standard of 0.08 percent blood-alcohol concentration was established a decade ago at the instigation of Congress. WASHINGTON - Thousands of people are killed or injured every year by drivers who have not reached the legal standard for being drunk but who have a reduced ability to see, make decisions or operate a vehicle, the National Transportation Safety Board said on Tuesday, and it recommended that the states reduce the allowable blood-alcohol concentration by more than a third, to 0.05 percent from 0.08 percent. The current standard was established a decade ago at the instigation of Congress, and progress has stalled, the board said, with about 10,000 fatalities a year. "There are at least 10,000 reasons to tackle this issue," said Deborah A.P. Hersman, the chairwoman of the board. Foreign countries with stricter standards have had substantially more success, according to the board. The board voted for a variety of recommendations. Some of them, like requiring that everyone convicted of drunken driving be required to install a breathalyzer interlock in their car, which would prevent the vehicle from starting without an alcohol test, were focused on heavy drinkers and repeat offenders. Officials said they hoped that a stricter standard would reduce drinking and driving both among social drinkers and among heavy drinkers. Blood-alcohol concentration varies by body weight, gender, stomach contents and other factors, but generally speaking, a 180-pound man could consume four beers or glasses of wine in 90 minutes without reaching the current limit. At a limit of 0.05 percent, he could legally consume only three. A 130-pound woman could probably consume three drinks in 90 minutes and still be legal under the existing standard; if the limit were lowered, she could consume only two. The blood-alcohol recommendation faces opposition. Sarah Longwell, the managing director at the American Beverage Institute, a restaurant trade association, called the idea "ludicrous." "Moving from .08 to .05 would criminalize perfectly responsible behavior," she said. And "further restriction of moderate consumption of alcohol by responsible adults prior to driving does nothing to stop hard-core drunk drivers from getting behind the wheel," she said. The board is already on record favoring research on built-in alcohol detectors, which could measure blood-alcohol content through a driver's palms on the steering wheel or some other unobtrusive way. Those could be available as an option on new cars or could be universally required. Either would affect drinkers who have never been caught driving, who make up more than 90 percent of those involved in fatal alcohol-related crashes. People with a blood-alcohol level of 0.05 percent are 38 percent more likely to be involved in a crash than those who have not been drinking, according to government statistics. People with a blood-alcohol level of 0.08 percent are 169 percent more likely. The standard in most of the industrialized world is 0.05 percent. All 50 states and the District of Columbia switched to 0.08 percent after President Bill Clinton signed a law in 2000 that withheld highway construction money from states that did not agree to that standard. "These tragedies affect both sides," said Robert J. Sumwalt, one of the board members. Mr. Sumwalt said his wife's first cousin was killed by a drunken driver who was traveling down a highway in the wrong direction. And his own cousin, he said, goes on Sundays to visit her 21-year-old daughter who was sentenced to 15 years in prison for drunken driving. Progress is mostly a matter of political will, board members said. About 30 percent of all vehicle fatalities are tied to drunken driving, down from 50 percent when President Ronald Reagan raised the issue 30 years ago. The number of deaths is down to about 10,000 a year from about 21,000 over the same period. Highway deaths are decreasing over all because of better-designed cars, seat belt use and better highways. The board has the support of other safety advocates, but not Mothers Against Drunk Driving. That group said it favored many parts of the board's agenda, including the mandatory installation of the breathalyzer interlock for anyone convicted of driving drunk, research on the passive alcohol sensors and "administrative license revocation," which gives police officers on the highway the authority to seize a driver's license at the time of an arrest. Those show strong potential for reducing the death toll, said J.T. Griffin, a Washington representative of the group. The discussion of changing the definition of drunk, Mr. Griffin said, was the safety board's "trying to focus on a group of people who are more social drinkers, who haven't been targeted in a while." MADD would not oppose the change, he said, but would pursue other remedies.