For drivers 55 and older, a single glass of wine at dinner can affect driving skills — even if alcohol levels are well below the mark at which the law presumes impairment (0.08 percent).
That's the finding of a study at the University of Florida in Gainesville.
Researchers discovered that a senior driver can be well below the legal definition of a drunken driver — and still be a potentially dangerous driver.
The study, which appeared in the journal Psychopharmacology, looked at how drinking nonintoxicating levels of alcohol affect the driving skills of two age groups. There were 36 people ages 25 to 35 in one group and 36 people age 55 to 70 in the other. The study revealed that while neither group imbibed enough alcohol to put them over the 0.08 mark, one drink could affect the driving skills of older drivers.
The researchers were Sara Jo Nixon, Ph.D., and professor in both the departments of psychiatry and psychology, and Alfred Sklar, a doctoral candidate.
One additional conclusion the researchers came to: It may be time to reassess the safe blood alcohol levels for all drivers.
The actual driving studies were done on simulators. The test subjects, all licensed drivers from the Gainesville and north central Florida area, stared straight ahead at a large computer monitor that displayed the driving route they would take. Two other monitors flanked the one straight ahead, mimicking the side windows of a car and what the drivers would see in their peripheral vision.
The groups took the same simulated driving test, first sober, then after an alcoholic drink. The task took each driver down a simulated 3-mile, winding country road. A stereo system played simulated driving sounds. And drivers sat at a console that consisted of a steering wheel and brake and gas pedals.
Occasionally, the drivers would encounter an oncoming car, for realism, but no driving distractions such as intersections or pedestrians.
The researchers assessed the drivers' ability to stay in the center of their lane and to maintain a constant speed, and they looked at how rapidly the drivers adjusted the steering wheel.
These simulations have been used to study the driving habits of older adults and they have been used to study how alcohol affects the driving habits of younger adults, but this is the first time they've been used to look at how alcohol affects older adult drivers, Sklar said.
Fred W. Wright Jr. is a freelance writer living in Seminole. He can be reached at [email protected]