The circadian rhythm, the wake-sleep cycle that goes on each night and day in the human body, affects everyone.
The problem for a trucker is that inadequate sleep may result in a lull in the circadian rhythm that could endanger not only the driver but everyone in the vicinity of the big rig, including you.
Disrupting the internal clock
Most commercial truckers are skillful, responsible drivers. They understand how important it is to be alert at all times. However, you sometimes see an 18-wheeler that is weaving and having trouble staying within its lane. Is the driver intoxicated? Distracted by something? Sometimes the cause is drowsiness related to the circadian rhythm.
If a driver has been on the road for too many hours with too little sleep, he or she may hit the “lull” that affects alertness and driving performance.
Most dangerous times
The Federal Motor Carrier Safety Administration conducted a study about driver alertness. The study indicated that truck accidents occur most often in the first hour of driving. The assumption is that sleep inertia plays a part and is strongest soon after a driver wakes from sleep. Sleep inertia refers to impaired performance in vigilance, cognitive function, short-term memory and reaction time among other driving-related tasks. The FMCSA also found that the level of alertness had to do with time of day more than time on task. Drivers of every kind of vehicle are less alert at night than during the day. Lack of alertness may be more pronounced in a truck driver who has spent long hours on the road.
Car versus truck
Whether you are driving in town or on the open road, chances are you will not have put as many hours into your trip as the trucker in the lane next to you. Always be alert to the possibility of a collision with a big rig that seems out of control. In a truck-car collision, the car and its driver will almost always suffer the most severe injuries—and it may be because the truck driver experienced the effects of a lull in the circadian rhythm.