What Should Count As Drunk Driving?

The National Transportation Safety Board (NTSB) wants to lower the legal limit:

Currently, the threshold is set at a blood alcohol content of 0.08 percent, as a result of a transportation bill signed into law by President Clinton in 2000, which stated that states had to adopt the 0.08 threshold by 2004 or else have their highway funding revoked. But in a new report, the NTSB argues that this threshold is too high, and that it should be reduced further to 0.05. For reference, the average woman weighing 165 pounds would have to consume three beers to top 0.05, four to top 0.08, and five to top 0.10 (change that to four, five and six for the average man weighing 195 pounds).

Kathryn Stewart supports the change:

The United States is among a handful of countries that sets the illegal blood alcohol concentration as high as 0.08 percent. Perhaps that is one reason we trail behind many other developed countries in our traffic safety record. In virtually every country where the illegal level has been lowered, lives have been saved.

When several European countries lowered their levels to 0.05 percent, researchers tallied the reductions in traffic deaths to be somewhere between 8 percent and 12 percent among drivers ages 18 to 49. And in Australia, fatal crashes decreased by 18 percent in Queensland and 8 percent in New South Wales after those states lowered their limits to 0.05 percent. In Sweden, when the illegal level went from an already-low 0.05 percent to 0.02 percent in 1990, the proportion of alcohol-related fatalities declined sharply, from 31 percent in 1989 to 18 percent in 1997. In our own country, lowering the limit from 0.10 to 0.08 was associated with reductions in impaired driving crashes and fatalities from between 5 percent and 16 percent.