The Federal Motor Carrier Safety Administration studies issues that affect safety for truck drivers and, by extension, the motorists around them.
Among those studies is the problem of truck driver fatigue, an issue that can relate to circadian rhythm disorder.
Fatigue among truck drivers
According to the Large Truck Crash Causation Study undertaken by the FMCSA, 13% of truck drivers who crashed suffered fatigue at the time the incident occurred. Fatigue can result from extended work hours, strenuous activities or insufficient sleep. Drowsiness affects the driver’s ability to respond quickly to a potentially hazardous situation and increases the chance of a crash.
About the circadian rhythm disorder
Circadian rhythm is the wake-sleep cycle to which the human body responds every day and every night. The cycle links to our internal clock and regulates our level of alertness. There are natural lulls in the cycle between 12:01 and 6:00 a.m. and again between 2:00 and 4:00 p.m. The FMCSA found that the level of alertness in drivers relates more to time of day than to time on task. Circadian rhythm disorder, a disruption of the wake-sleep cycle, could cause daytime drowsiness, as well as difficulty with decision-making and concentration. The issue could become more pronounced during the natural lulls.
Sleep inertia adds to the concern
Another study found that crashes are more apt to happen during the first hour of driving when sleep inertia can result in impaired vigilance, reaction time and cognitive functioning. Sleep inertia is more likely to affect drivers who sleep in the truck’s sleeper berth because they often get back on the road shortly after waking.
When the unthinkable happens
A motorist is unlikely to know whether the driver of the big rig in the next lane is experiencing fatigue until long after a crash occurs. Truck-car collision cases are complex. The cause of a crash could involve anything from overloaded cargo to a driver with circadian rhythm disorder. A thorough investigation will eventually reveal the reason for the collision and focus on the injured victim’s compensation.