My guess is most people already know that, but also figure they can get away with a sip or two of wine or beer or even hard liquor. This study strongly suggests they are wrong.
"This is government data on an enormous number of cases," Phillips said. "We didn't invent any of this stuff."
Although he admits the findings were at first startling, he said he only had to look at his own past to believe them.
"When I was in college I used to play pool," he said. "My opponent, who was not as good a pool player as I was, would say to me wouldn't you like half a glass of beer. And I noticed that even with half a glass of beer inside of me, I was a less good pool player.
"Half a glass of beer would probably be even less than .01 concentration, but when you are playing pool a very, very tiny difference at one end can result in quite a big difference in your score."
Legal limits for alcohol and punishment for exceeding those limits vary from country to country, and even among adjacent communities. According to Phillips, they are "based on cultural and political and historical considerations, not just on data."
There is, however, much data on how to deal with drivers who have exceeded the legal limit.
A study at the University of Missouri-Columbia suggested that the risk of getting caught is probably a stronger deterrent than the perceived chance of getting in an accident. Participants in that study were much less likely to drive if they thought they might get arrested.
In the small town I live in, even first offenders spend a few nights in jail. But even worse, the local paper publishes their names, so all their neighbors know.
Researchers at the University of Florida took that a step further. They concluded that the "threat of immediate suspension of the driver's license is a larger deterrent than the threat of more severe penalties that may occur at a later date."
They compared the results to house-training a puppy.
"If you punish your dog two weeks after wetting the carpet, the behavior is not affected," the Florida researchers noted. "If you punish a drunk driver six to 10 months after the crime, the behavior is not changed. If you suspend the license immediately, the connection is made and the behavior is affected (at least in most cases.)"
And now, according to Phillips, it's unwise to wait until the driver is drunk. Maybe half a beer is all it takes to kill someone.