WASHINGTON (CNN) - A decade-old benchmark for determining when a driver is legally drunk should be lowered in an effort to reduce alcohol-related car crashes that claim about 10,000 lives each year, U.S. safety investigators said on Tuesday.
The National Transportation Safety Board recommended that all 50 states lower the threshold from 0.08 blood-alcohol content (BAC) to 0.05.
The idea is part of a safety board initiative outlined in a staff report and approved by the panel to eliminate drunk driving, which accounts for about a third of all road deaths.
The board acknowledged that there was "no silver bullet," but that more action is needed.
"This is critical because impaired driving remains one of the biggest killers in the United States," NTSB Chairman Debbie Hersman said ahead of a vote by the panel on a staff report.
Hersman said progress has been made over the years to reduce drunk driving, including a range of federal and state policies, tougher law enforcement, and stepped up national advocacy. But she said too many people are still dying on America's roads in alcohol-related crashes.
Lowering the rate to 0.05 would save about 500 to 800 lives annually, the safety board report said.
"In the last 30 years, more than 440,000 people have perished in this country due to alcohol-impaired driving. What will be our legacy 30 years from now?" Hersman asked. "If we don't tackle alcohol-impaired driving now, when will we find the will to do so?"
Under current law, a 180-pound male typically will hit the 0.08 threshold after four drinks over an hour, according to an online blood alcohol calculator published by the University of Oklahoma. That same person could reach the 0.05 threshold after two to three drinks over the same period, according to the calculator.
Many factors besides gender and weight influence a person's blood alcohol content level. And many states outlaw lower levels of inebriation when behind the wheel.
The NTSB investigates transportation accidents and advocates on safety issues. It cannot impose its will through regulation and can only recommend changes to federal and state agencies or legislatures, including Congress.
But the independent agency is influential on matters of public safety and its decisions can spur action from like-minded legislators and transportation agencies nationwide. States set their own BAC standards.
The board also recommended on Tuesday that states vastly expand laws allowing police to swiftly confiscate licenses from drivers who exceed the blood alcohol limits.
And it is pushing for laws requiring all first-time offenders to have ignition locking devices that prevent cars from starting until breath samples are analyzed.
In the early 1980s, when grass-roots safety groups brought attention to drunk driving, many states required a 0.15 BAC rate to demonstrated intoxication.
But over the next 24 years, Mothers Against Drunk Driving and other groups pushed states to adopt the 0.08 BAC standard, the last state falling in line in 2004.
The number of alcohol-related highway fatalities, meanwhile, dropped from 20,000 in 1980 to 9,878 in 2011, the NTSB said.
In recent years, about 31 percent of all fatal highway accidents are attributed to alcohol impairment, the NTSB said. But most of the decline in highway deaths occurred in the first decade.
"I think .05 is going to come. How long it takes to get there, we don't know. But it will happen," said the NTSB's Robert Molloy, who helped guide the staff report.
For some, the vote struck close to home.
NTSB board member Robert Sumwalt noted that one of his relatives had been killed by a drunk driver, and another is serving a 15-year sentence in a related death.
Many of the recommendations "are going to be unpopular," Sumwalt said, "but if we keep doing what we're doing, we're not going to make any difference."
The NTSB said even very low levels of alcohol impair drivers.
At 0.01 BAC, drivers in simulators demonstrate attention problems and lane deviations. At 0.02, they exhibit drowsiness, and at 0.04, vigilance problems.
The safety board recommend to the National Highway Traffic Safety Administration (NHTSA) that it provide financial incentives to states to implement the changes.
At Tuesday's meeting, the safety board also championed laws allowing police to confiscate a motorist's license at the time of arrest if the driver exceeds a BAC limit, or refuses to take the BAC test.
Some 40 states already use the administrative tool, which the NTSB believes is effective because it is swift and immediate.
And the board recommended more widespread use of passive alcohol sensors, which police can use to "sniff" the air during a traffic stop to determine the presence of alcohol.
The sensor is capable of detecting alcohol even in cases where the driver has attempted to disguise his breathe with gum or mints. If the sensor alerts, it is grounds for more thorough testing.
The NTSB timed the recommendation to coincide with the deadliest alcohol-related highway crash in U.S. history.
On May 14, 1988, a drunk driver drove his pickup the wrong way on Interstate 71 near Carrollton, Kentucky. The truck hit a school bus, killing 24 children and three adults and injured 34 others.