by

Charles A. Bertrand, M.D., FACP, DIM-CD (Ret.)
Associate Clinical Professor of Medicine at New York Medical College
and at the Medical University of South Carolina

THE DANGERS OF DWD

Everyone understands the dangers of DUI - Driving Under the Influence. Mothers Against Drunk Driving has done a particularly effective job of spreading the word. On the other hand, few people understand that DWD - Driving While Drowsy can be just as perilous.

Fortunately, in a recent issue of the Journal of the American Medical Association--Vol 337, No. 11 pp755-761 (September 11, 1997) -- a group of researchers from La Jolla Clinic in California have called attention to this disturbing problem in an article called "The Sleep of Long Haul Truck Drivers." In this article, M. M. Mitler and others reported on a study involving four groups of 20 male truck drivers who travelled a total of some 204,000 miles. Two of the groups were from Canada and two from the United States.

Roughly half drove at night for 13-hour shifts in Canada and the others drove ten-hour day-time shifts in the United States.

They were monitored by electroencephalograms {EEG's}, and by cameras that focused on their faces. Computers measured automobile speed, recorded changes in their position as well as other variables.

The results were quite revealing. For one thing, in a self administered questionnaire, the drivers estimated that their ideal amount of sleep to remain alert was 7.1 hours. Yet during the study the drivers spent an average of only 5.18 hours in bed, including rest, sleep and naps. The average duration of actual sleep, however was only 4.78 hours per day. Thus, over a four-day haul, their sleep deprivation amounted to some eight hours, and for five days the deprivation added up to around ten hours.

Over half the truckers had at least one interval of the drowsiness while driving, and some had several. Indeed, two of the drivers -- one aged 25 and the other aged 30 -- had seven brief episodes of grade-1 sleep while driving, characterized by non-rapid eye movements and certain changes on the EEG. Visual recordings show drowsy drivers in about seven percent of the cases on a variable basis.

The main trouble spots during the night occurred from about midnight to six or seven a.m. But these episodes also occurred between two and four p.m. The conclusion of the study: Driver fatigue is the number one problem in commercial transportation.

A companion editorial appeared in the same issue, written by w.c. Dement of Stan ford University \. In his commentary, Dement used multiple sources to support his conclusions. He pointed out that scientists have known for over two decades that loss of sleep accumulates over time and does not dissipate. (In this study drivers who were on the road for four to five days built up a sleep deficit of eight to ten hours by the last day). Small wonder that several studies have identified fatigue as the leading cause of truck crashes.

Few people would boast that they had driven while intoxicated the previous evening. However, the public is all too tolerant of drowsy drivers. People shake their heads, smile and say, "I almost fell asleep twice last night while I was driving home."

Yet consider this fact: Sustained wakefulness for 17 hours is approximately equivalent to a blood alcohol concentration of 0.06 percent, or about three ounces of whiskey. So which is more dangerous on the highway.

As a matter of fact, two victims groups have been organized to combat irresponsible sleeping habits in the trucking industry -- Parents Against Tired Truckers and Victims of Irresponsible Drowsy Drivers. These organizations recognize a fact that should be obvious to any thoughtful person -- both drunk drivers and drowsy drivers are responsible for their own impairment and have an obligation to stay off public highways.

The National Highway Safety Administration estimates that these accidents cost Americans $12.4 billion annually. Even more distressing, about 1,500 people are killed every year as the result of drivers who fall asleep at the wheel -- and another 76,000 are injured.

The bottom line for you and me: Don't drive while drunk and don't drive drowsy. You need to be awake every second you're on the road -- if only to dodge the sixteen-wheelers driven by sleepy truck drivers.


The advice provided on this website is intended to be general in nature and should not be relied upon for specific treatment. If you need personal medical attention please contact your physician.

Copyright © Dr. Charles A. Bertrand.
All rights reserved.