September 8, 2013

Blurry issue: Blood alcohol and driving

Expert opinion varies as the question of what constitutes impaired driving is up for debate.

By TED GREGORY/Chicago Tribune

IOWA CITY, Iowa - 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.

Push to lower legal limit of intoxication to 0.05 stirs debate
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A volunteer driver takes the wheel at the University of Iowa National Advanced Driving Simulator in Coralville, Iowa, on Aug. 20.

Chuck Berman/Chicago Tribune/MCT

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."


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 hockey 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.

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