— Timothy Brown has put hundreds of drunken drivers behind the wheel.
In the research center where he works, the drivers ingest vodka or 151-proof alcohol and get behind the wheel of a Chevrolet Malibu mounted in a metal pod about the size of a two-car garage. Then they take a spin in what's considered the world's most sophisticated driving simulator, while Brown and his colleagues gather data.
Brown is using that data to better understand the difference in driving abilities of someone who is sober, someone who has had a few drinks and someone who has had a few more drinks. That work has been made especially timely by a controversial National Transportation Safety Board recommendation to lower the legal limit of intoxication to a blood alcohol content of 0.05 from 0.08.
Brown, senior research associate at the $100 million National Advanced Driving Simulator in Iowa, is looking to isolate the precise differences in driving performance with no alcohol in the blood and at a level of 0.05. His work is expected to shed light on the national debate.
"My heart doesn't tell me anything," Brown said when asked for his best guess on whether 0.05 was serious impairment. He acknowledges that diminished performance happens at 0.05 but would not elaborate "because I'm a researcher and the data drives me."
Over Labor Day weekend, one of the busiest holiday driving weekends when an estimated 30 million drivers will take to the roads, authorities will be on the lookout for those who attempt the potentially dangerous mix of drinking and driving. But what constitutes dangerous driving is once again up for debate.
Calling impaired driving "a national epidemic," NTSB Chairwoman Deborah Hersman made the 0.05 recommendation in May. It was one of several proposals that include high-visibility DUI enforcement, expanded use of alcohol-sensing technology and ignition interlock devices, and more DUI treatment courts.
Research suggests that lowering the legal limit of intoxication to 0.05 could save 500 to 1,000 lives a year.
But many safe-driving advocates are conspicuously silent on the issue of whether 0.05 is high enough impairment to merit criminal charges. Mothers Against Drunk Driving is standing down, as is Illinois Secretary of State Jesse White. The venerable Insurance Institute for Highway Safety, which notes that it never takes formal positions on policy, said police will have trouble enforcing 0.05.
At the core of concerns about 0.05 is the tricky issue of when alcohol impairment becomes criminally negligent. How does slight alcohol impairment differ from impairment caused by drowsiness, cellphone use, medication, aging or other conditions? Is it reckless to get behind the wheel after two glasses of wine at a dinner party? A large beer at a Blackhawks game? A couple of cocktails at a reception?
Research on the topic is voluminous — and resembles a weaving car.
The National Sleep Foundation states that drowsiness is very similar to alcohol impairment and "can impair driving performance as much or more so than alcohol," according to a report on the topic. Being sleepy can slow reaction times, limit vision and create lapses in judgment and delays in processing information, the foundation states.
"In other words," the foundation reports, "driving sleepy is like driving drunk."
A 2003 study by University of Utah showed that motorists who talk on cellphones — hands-free or not — are as impaired as drivers at a 0.08 BAC. Study participants drove slower and hit the brakes and accelerated later than those driving undistracted. Drunken drivers drove slower than cellphone users and undistracted drivers but more aggressively. They also followed more closely and hit their brakes more erratically, the research showed.
As to whether such a thing as responsible drinking and driving exists, some research shows that lane deviations and attention lapses occur at a BAC as low as 0.001. MADD and the National Institute on Alcohol Abuse and Alcoholism recommend no one drive after drinking.
But the American Beverage Institute, which represents restaurant and bar owners, calls the 0.05 recommendation an effort to "criminalize perfectly responsible behavior," saying that less than 1 percent of traffic fatalities in the U.S. are caused by drivers with a BAC from 0.05 to 0.08. The organization points to National Highway Traffic Safety Administration data showing that 70 percent of drunken driving deaths involve a driver with a BAC of 0.15 or higher.
In making its recommendation in May, the NTSB noted that more than 100 countries, including many in Europe, have set 0.05 as the legal limit of intoxication and experienced significant drops in traffic fatalities after doing so. Drunken driving accounts for nearly 10,000 traffic fatalities a year in the U.S.
"The research clearly shows that drivers with a BAC above 0.05 are impaired and at a significantly greater risk of being involved in a crash where someone is killed or injured," the NTSB's Hersman said in recommending the lower level.
Sarah Longwell, managing director of the American Beverage Institute, contends the NTSB research lacks context. The significantly greater risk that the NTSB points out is no different than the risk that accompanies listening to a loud car radio or having a passenger talking to the driver, she said.
Emphasizing other countries that set their legal definition of intoxication at 0.05 is "an apples to oranges comparison" to the U.S., Longwell said. Many of those countries have "vastly different" driving, mass transit and drinking cultures, she said. In addition, the countries imposed "other draconian measures," including random breath testing, that contributed to the decline in traffic fatalities and would be unacceptable in the U.S., Longwell added.