This article published in AAA magazine discusses the National Transportation Safety Board’s call to reduce the legal blood alcohol concentration limit from .08 to .05 for all drivers.
It’s an issue of law, but the evidence also strongly suggests driving even at a .05 – .08 increases the chances of an accident.
The Science Behind .05
Plenty of studies — at home and abroad — back up the NTSB’s call for a reduced BAC limit
Technically, impairment begins with the first drink. Legally, for drivers in the United States at least, it begins at a blood alcohol concentration of .08. Scientifically, however, its tragic effects seem to become truly magnified at a BAC of .05.
When the National Transportation Safety Board released a safety report called “Reaching Zero: Actions to Eliminate Alcohol-Impaired Driving” in May 2013, it included a list of 19 recommendations that, if enacted, could make considerable progress toward the project’s ambitious goal.
One lightning-rod bullet point, however, received the most attention by far: the NTSB’s call to reduce the legal blood alcohol concentration limit from .08 to .05 for all drivers.
In a presentation to Public Affairs delegates at the 2014 AAA Annual Meeting, former NTSB member Mark Rosekind made clear that the .05 figure wasn’t “just pulled out of a hat” and that there was plenty of science behind it. More than 70 countries already have an .05 limit or lower, including most of Europe, South America and Australia.
“The U.S. is behind,” Rosekind said in a recent follow-up interview. “As bold as everybody likes to think this is, the reality is that 70 countries around the world have already gone to .05 or lower. While we pride ourselves in the United States on being on the cutting edge of transportation safety, we are woefully behind. “The rest of the world is there. We’re just catching up.”
Indeed, the science is consistently clear:
• A 2000 study showed that the risk of fatal crash involvement at BACs between .05 and .08 ranged from 3 to 17 times greater depending on the age of the driver and the type of fatal crash.
• Studies in 2002 and 2005 showed that at a BAC level of .05, drivers are 1.38 times more likely to be in a crash than sober drivers. At .08, the risk jumps to 2.69 times higher.
• Since .05 BAC limits were instituted in Australia, Japan and many European nations, studies have shown that fatal crashes have decreased and injuries have been reduced in those countries. Fatal crashes among males ages 18 to 49 in Europe have markedly decreased and overall fatal crashes in Australia were reduced up to 18 percent.
• A 2014 study showed that in two-vehicle accidents between drivers with BAC levels of .05 to .07 and drivers with BAC levels of .08, the drivers with the lower BAC levels were found solely at blame for the crash just as often as the .08 drivers.
The mere establishment of a .05 limit likely would discourage many drivers from drinking and driving at all. In the Canadian province of British Columbia, September 2010 laws enacted immediate vehicle impoundment, a 72-hour driver’s license suspension and heavy fines for BACs between .05 and .08, with more severe sanctions for multiple offenders and those with BACs of .08 or above.
The results? A September 2012 study showed that drivers with BACs over .08 decreased by 59 percent and drivers with levels from .05 to .08 decreased by 44 percent from 2010. Decreases in drinking and driving were universal across all age groups, sex and communities, and 92 percent of drivers were aware of the new sanctions. Overall, levels of drinking and driving were the lowest ever recorded in the province.
The effort to reduce the BAC threshold from .10 to .08 in the U.S. took two decades, so when it released its 2013 report, the NTSB realized it was just a starting point.
In the two years since, legislation to lower BAC limits has been introduced in five states – Kentucky, New York, South Carolina, Vermont, and Washington – and a hearing on the topic has been held in Utah. None of these initiatives achieved serious traction.
A number of organizations support the NTSB’s call for a lower limit, including the American Trucking Association, the American Society of Safety Engineers, the American Medical Association and the World Health Organization. AAA agrees that the science is clear on impairment below .08 BAC. And while AAA is not currently pushing for changes in state laws, the club has begun to educate its members and the public about the risks of driving while impaired at lower BAC levels — an integral first step to changing public opinion on this safety issue.
According to the AAA Foundation for Traffic Safety, 63 percent of motorists support lowering the limit for a driver’s blood alcohol concentration from 0.08 to 0.05 g/dL, compared to 36 percent who oppose such a measure.
“The biggest barrier is education,” Rosekind said. “Impairment starts with the first drink. People will say, ‘You mean I can’t have one drink?’ No, this is about saving lives, about saying this is what science shows, and here’s how you manage it.”
“It’s not about drinking,” he added. “It’s about separating the drinking from the driving.”
AAA South Jersey – AAA July Aug 2015 : The Science Behind .05
The Science Behind .05