To curb drunken driving, the federal National Transportation Safety Board has voted to recommend that states tighten the legal limit for drivers' blood alcohol.
The threshold now for drunken driving is a blood alcohol concentration of 0.08. (The BAC equals alcohol divided by the volume of blood it's in.)
The NTSB would push for it to be lowered to 0.05, in line with the limits in countries such as Denmark, the Philippines and Switzerland.
How many drinks would it take to run afoul of the new limit? The answer depends on weight, gender and how long a person has been drinking.
A man weighing 180 pounds who drank three beers in an hour would have a BAC of 0.052, according to a calculator on the Wisconsin Dept. of Transportation website. A 120-pound woman would hit the same level drinking two beers over 60 minutes.
At 0.05 BAC, drivers have worse coordination and can't keep track of moving objects all that well, the National Highway Traffic Safety Administration says.
"We need as much attention today on impaired driving as we saw in the early 1980s when organizations like MADD were founded and the drinking age became 21," said the text of a speech to be given by Deborah A.P. Hersman, chairman of the NTSB, at the start of a two-day meeting on impaired driving. "Over that decade, real progress was achieved in the United States."
More than 10,000 highway deaths in 2010 involved an alcohol-impaired driver, according to the NTSB. While that's down from more than 18,000 in 1988, the NTSB says it could be reduced further still with strichter alcohol limits.
But it looks like a tough sell. "When the limit was .10, it was very difficult to get it lowered to .08," Jonathan Adkins, a spokesman for Governors Highway Safety Association told USA Today. "We don't expect any state to go to .05."