Truck Drivers Don’t Get Enough Rest, Study Says Research Finds Some Truckers In Sleeplike State While Driving

A weeklong, moment-by-moment study of 80 truck drivers found that they got too little sleep to stay alert, less than five hours a night, and that two drivers had repeated episodes of a sleeplike state while they were driving.

Part of the study, which was sponsored by the Department of Transportation, is described in an article that appears in The New England Journal of Medicine today.

The article also said that the drivers themselves said they needed about seven hours of sleep a night. Those who worked nights got only about four and a half hours of sleep daily, probably because it is harder to sleep in the daytime, the study said; those who worked days got a little under six hours of sleep.

The National Transportation Safety Board estimates that truck drivers who fall asleep at the wheel are a factor in 750 to 1,500 road deaths every year. New regulations updating the 1937 federal duty and rest rules for commercial truck drivers are on on the agency’s list of “most wanted” safety improvements.

Of nearly 30,000 video recordings made of the drivers as they worked, about 7 percent, nearly 2,000, “were judged to show a drowsy driver,” the article said. The drivers also were wired for brain activity and eye movement monitoring. Of the 80 drivers, 45 showed at least one drowsy episode, but half the episodes involved just eight drivers, lending credence to the idea that the need for sleep differs among individuals.

On seven occasions, two drivers who were behind the wheel in trucks moving faster than 45 miles an hour showed brain waves and eye movement patterns that researchers define as sleep.

“If they were lying in bed with the lights out and their eyes closed and they showed those patterns, we would say they were in their first stages of sleep,’ said James C. Miller, a sleep researcher at the Scripps Clinic and Research Foundation, in La Jolla, alif., and one of the authors. But, the paper said, “It may not be correct to use standard sleep-scoring criteria for records obtained when the subject is behaviorally active as opposed to lying in bed.”

Miller said “the whole definition of falling asleep falls apart here.” He said the episodes were “disturbing and curious.”

None of the 80 drivers had an accident during the week studied. Another sleep expert not affiliated with the study, Elaine Weinstein, the chief of the safety studies division of the National Transportation Safety Board, said the study was “very sophisticated and very well done.”

She said, however, that the fact that the drivers knew they were being monitored - in fact, they were literally wired up - might have put them “on their best behavior” and might have skewed the results.

The study also found that most incidents of drowsiness occurred during night hours, when people are used to sleeping but when many trucks are on the road. This was consistent with earlier studies.

The study followed 40 drivers in the United States and 40 in Canada. In both countries, drivers can be scheduled for a maximum of 15 hours of duty, followed by eight hours of rest. In the United States, the maximum period spent driving is 10 hours; in Canada it is 13. But Miller said the difference was not important to the study, because the main factor in fatigue was hours of wakefulness, not hours of driving.

The study also found that many drivers did not get, or did not take, eight-hour breaks. And this study repeated a finding of others, that getting eight hours off between work shifts does not allow for eight hours of sleep.