Obstructive sleep apnea is only one aspect of the serious problem of driver fatigue, something said to contribute to a third of bus and motorcoach collisions.
Drivers without obstructive sleep apnea who follow hours-of-service rules still may hit the road with lingering fatigue due to poor off-duty sleep hygiene or scheduling, said Bob Crescenzo, Vice President of Safety and Loss Control at Lancer Insurance Company in Long Beach, N.Y.
Federal officials have dropped plans for increased scrutiny and regulation of OSA on commercial motor vehicle drivers, saying current safety programs are sufficient to address it (see story Page 12). However, Crescenzo says, the most common cause of driver fatigue may simply be lack of sleep.
“Motorcoach companies generally don’t know how much a driver sleeps. He may have been off-schedule for twelve hours or three days, so the company thinks he’s fresh when he comes back. But they don’t know that,” he said. “He might not have good sleep behavior or have other issues at home. Anything interrupting restful sleep increases overall fatigue, which may result in a higher crash risk.”
Medical issues or life stressors may prevent drivers from achieving the seven hours of quality nightly sleep that is believed necessary for normal human performance, Crescenzo said. “We know drivers who get fewer than five hours of sleep have a much higher risk of crashes.”
Lancer has been studying driver fatigue in accident claims for about 15 years, he said, partly because some 20 to 30 percent of the company’s claims are fatigue-related. If a driver takes no action in the six to seven seconds before a crash, that’s an indication they’re distracted by fatigue.
This lack of quick response often shows up in high-claim accidents such as running off the road, rear-ending another vehicle at an intersection and head-on collisions, Crescenzo said, all of which end up as expensive claims—and a high risk to life.
A National Academy of Sciences 2016 report titled “Commercial Motor Vehicle Driver Fatigue Research Needs” showed that 10 to 20 percent of fatal commercial motor truck and bus crashes may involve fatigued drivers.
Fatigue, they wrote, “in addition to compromising alertness and vigilance, prolonged time on task, inadequate breaks, reduced sleep time and limited time off duty, individually and collectively, can slow reaction time and cognitive processing speed and degrade working memory, situational awareness and impulse control.”
Putting research to practical use
The human body has three daily periods “when it wants to express its greatest need for sleep,” Crescenzo said—mid-afternoon, 11-12 p.m., and 4-6 a.m. Early morning, in particular, he says, is a time people biologically want to be asleep. Ever-changing work schedules and overnight trips are particular hazards for motorcoach drivers, he said.
“We recommend that the coach or bus not be used as a rolling hotel. We strongly discourage overnight drives unless a driver has been prepared three to five days in advance by sleeping during the day and being awake at night.”
Lancer Insurance provides fatigue management programs to its customers for drivers and managers, Crescenzo said. Manager programs focus on creating schedules that prioritize human sleep needs as well as business needs.
The United Motorcoach Association and other organizations additionally endorse the North American Fatigue Management Program, which provides a comprehensive approach to addressing commercial driver fatigue. Information is available at www.nafmp.com.
No substitute for sleep
Recent medical research has uncovered more details about the crucial brain maintenance that occurs during sleep. The discoveries make it clear that caffeine, energy drinks and other remedies cannot overcome biology.
The restorative function of sleep has long been recognized but not understood. In 2012 researchers identified a “glymphatic system” of fluid exchange that flushes toxins from the brain during sleep. The system was described as “The Garbage Truck of the Brain” in a paper published by neuroscientist Maiken Niedergaard of the University of Rochester School of Medicine.
The paper, published in the journal Science, explained that the brain uses about 20 percent of the body’s energy, creating toxic wastes that impair and eventually damage neuronal tissues. The brain, unlike other tissues, does not clear cellular waste as it is produced: the busy brain isn’t able to do maintenance during working hours.
The National Academy of Sciences driver fatigue study summarized: “There is no biological substitute for sufficient sleep.”
Tips for staying alert
Be aware of signs that you’re in the drowsy danger zone. That includes:
- difficulty focusing, frequent blinking or feeling that eyelids are heavy
• trouble remembering the last few miles driven or missing exits and traffic signs
- drifting from the lane, tailgating or hitting a rumble strip
Getting good sleep at night is essential, too, and the appropriate range is from seven to nine hours for adults. To make those hours count:
- Establish a regular bed and wake time, and avoid alcohol, caffeine and nicotine close to bedtime.
• Exercise regularly but complete the workout at least three hours before going to bed.
• Establish a relaxing “wind-down” bedtime routine and create a sleep-conducive environment that is dark, quiet and comfortable. Particularly avoid glowing screens (that includes your phone) for two hours before bedtime.
Source: National Sleep Foundation, sleepfoundation.org.