Joseph Evangelist l NationaLease Member l 2018
Research from the National Institute for Occupational Safety and Health shows that over 30% of American workers aged 30-64 are short of sleep. The National Sleep Foundation recommends that healthy adults sleep seven to nine hours per day, but a recent survey found that 30% of civilian-employed adults (approximately 40.6 million workers) reported average sleep duration of six hours or less per day. It’s not known precisely where the truck driver population sits in terms actual hours of sleep per day, but it’s probably statistically similar, if not worse.
The current HOS rules require 10 hours off duty before driving, eight of which must be in the sleeper berth — but they do not and cannot mandate that drivers actually sleep for the seven to nine recommended hours. To use Knipling’s term, conscientious self-management compels most drivers to get as much sleep as they can within their off-duty period, but not everyone can sleep at a given time of the day. Nor can anyone be assured of a full restful sleep if they have stuff on their minds or some physical or medical issue preventing them from getting proper sleep. Obviously, noisy parking lots or sleeping in a dangerous area can affect the quality of sleep.
Short sleep leads inexorably to drowsy driving. The real problem is not that the driver didn’t get enough rest, but failing to recognize that likelihood and to build a little slack into the plan to account for it.
“Even among healthy individuals there’s a huge difference in how susceptible people are to drowsiness,” Knipling says. “Some people have no difficulty staying alert all day long, whereas others can really benefit from a mid-day nap. It all depends on their individual patterns of sleep and wakefulness and their susceptibility to drowsiness.”
According to Knipling, aside from possible medical issues such as obstructive sleep apnea, the top four predictors of individual sleepiness are:
the previous amount of sleep
time of day
elapsed time since the previous sleep.
“We now have a requirement that drivers take a 30-minute break some time before the end of the eighth hour on duty, but that’s not really a practical solution,” Knipling says. “There needs to be more widespread recognition within the industry that being tired and taking breaks and napping are normal parts of people’s lives.”
Driving at night can be challenging because of the body’s biologically hardwired ten-dency to sleep when it’s dark. Lighter traffic densities, however, mean it’s statistically safer.
See How to Manage Fatigue here: