Tougher Drunken Driving Threshold Weighed

Federal accident investigators were weighing a recommendation Tuesday that states reduce their threshold for drunken driving from the current .08 blood alcohol content to .05, a standard that has been shown to substantially reduce highway deaths in other countries.

The federal proposal to lower the DWI blood alcohol limit would make the standard similar to European nations and Australia, and could save lives, says a University at Buffalo School of Social Work research professor who has studied the effects of impaired driving for more than 25 years.

“The move to a .05 blood alcohol level (from 0.8) is not a new idea,” says Thomas H. Nochajski, PhD, whose research includes preventing alcohol and drug problems for families and children. “The European nations and Australia have had .05 as the legal limit for a number of years. The issue is whether lowering the BAC level will result in saving lives.”

The lower threshold was one of a series of recommendations aimed at reducing drunken driving made by the National Transportation Safety Board’s staff in a report presented at a meeting of the board.

Nochajski says a direct effect on saving lives could very well occur.

“We saw a drop in fatalities after the BAC level was lowered from .10 to .08, and may see a similar decrease if it is lowered to .05,” Nochajski says.

New approaches are needed to combat drunken driving, which claims the lives of more than a third of the people killed each year on U.S highways – a level of carnage that that has remained stubbornly consistent for the past decade and a half, the board said.

“Our goal is to get to zero deaths because each alcohol-impaired death is preventable,” NTSB Chairman Deborah Hersman said. “Alcohol-impaired deaths are not accidents, they are crimes. They can and should be prevented. The tools exist. What is needed is the will.”

Dramatic progress was made in the 1980s through the mid-1990s after the minimum drinking age was raised to 21 and the legally-allowable maximum level of drivers’ blood alcohol content was lowered to .08, the report said. Today, drunken driving claims about 10,000 lives a year, down from over 18,000 in 1982. At that time, alcohol-related fatalities accounted for about 40 percent of highway deaths.

But progress in cutting the rate further has largely stagnated, and board members have called for a fresh approach.

There were about 900 fatal crashes in 2011 where one of the drivers had a BAC between .05 and .07, according to Nochajski.

“So crashes do occur at this BAC level,” he says. “In fact, the risk for being involved in a fatal crash for individuals with a BAC between .05 and .0799 ranges from a high of almost 10 times that of a driver with a BAC level of o.oo for males ages 16 to 20, to a low of almost four times for males and females over the age of 35.”

Research into impaired driving shows that certain functions important for good driving begin to be affected after a single drink, Nochajski notes.

“We know that vision, decision-making, information processing, distance judgment, distraction and reactions are all influenced by low levels of alcohol,” he says. “So the move to the .05 level is not out of line with the research findings.”

Nochajski also says for the average male, it takes approximately three drinks in one hour to reach the .05 level, and around two drinks for a female.

Technology may be part of the solution, and anti-drunken driving forces have talked of turning cars into a part of the solution.

In December, the board called on the National Highway Traffic Safety Administration and the auto industry to step up their research into technology for use in all vehicles that can detect whether a driver has elevated blood alcohol without the driver breathing into a tube or taking any other action. Drivers with elevated levels would be unable to start their cars.

But the technology is still years away.

A combination of approaches will be needed to effectively drive down fatalities, researchers told the board at a two-day forum on drunk driving last year.

Reducing the blood alcohol limit below .08 could save over 7,000 lives a year, the Insurance Institute for Highway Safety has estimated.

Australia saw a 12 percent decline in alcohol-related deaths as a share of overall traffic fatalities when it lowered its legal limit to .05. The limit in most of Europe is also .05, and in some countries it’s as low as .02.

A woman weighing less than 120 pounds can reach .05 after just one drink. A man weighing up to 160 pounds reaches .05 after two drinks.

A recommendation made by researchers last year has been to expand the use of alcohol ignition interlock devices by drivers convicted of driving under the influence. The devices usually require a driver to breathe into a tube, much like the breathalyzers police ask suspected drunken drivers to use.

Expanded use of high visibility checkpoints by police has also been recommended.