Drowsy Drivers
Posted By Clod on May 31, 2011
Planning a long vacation trip in the car this summer? Great, but don’t stay at the wheel so long you get sleepy. A Stanford Medical Center authority on sleep says driving while drowsy is as dangerous as driving drunk, and maybe even more dangerous.
Nelson B. Powell, M.D., co-director of the Stanford Sleep Disorders Clinic and Research Center, said a study he did in collaboration with researchers from Washington University in St. Louis found that the reaction time of severely sleep-deprived drivers was as slow as that of drivers who were legally drunk.
On a General Motors 1.4-mile test track in Arizona, healthy adults who were seriously sleep-deprived took an average of 300 milliseconds to react to a hazard. Those whose blood alcohol level was slightly higher than the legal standards for intoxication in California, 0.08 percent, took 294 milliseconds.
Powell said he hoped the study results would spur more public dialogue on the dangers of sleepy driving, and lead to more research. “It’s crucial that people recognize the danger of driving while sleepy, and stay away from their cars while they’re tired,” he said.
A large percentage of Americans get way too little sleep and are sleepy during the day. Powell said the risks of that were not widely understood, and that was why his team did the study.
It began by having 16 healthy adult volunteers drive the GM course while fully rested. Several hazards were put in their paths, and they were judged in part by their reactions to them. Then the test subjects were divided into three groups. One was tested after spending a night without sleep, the second after getting no more than two hours of sleep for seven nights in a row, and the third after consuming enough alcohol to raise their blood alcohol level to an average of 0.089 percent.
But they were a little surprised to find that there was virtually no difference between the alcohol-impaired and the sleep-deprived group when it came to reaction times and overall performance. Powell said that means that driving while sleepy is at least as dangerous — if not more dangerous — than driving while intoxicated.
The results of the study, co-authored by Powell and the Washington University researchers, were published in the May 2001, issue of the medical journal Laryngoscope. General Motors Corp. and NBC News collaborated in the project.
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