Just about everyone can relate to that “nodding off” feeling after lunch, or that sudden wave of insuppressible yawning. In the middle of the day, our body temperature dips slightly, as do the alerting signals from our brain. Under normal circumstances this shouldn’t be a problem. But for the millions of Americans that are even mildly sleep deprived, it can spell disaster.
Nodding Off at the Wheel
Every year, there are millions of accidents on our roads and in the workplace directly attributed to sleep deprivation. Nodding off for a second or two in front of the TV is one thing, but in a car traveling sixty miles per hour is another. Behind the wheel, you’ll travel between 90 – 180 feet in total oblivion during that second or two– plenty of distance to unintentionally change lanes or miss a curve.
In fact, while you were reading the preceding paragraphs, three motor vehicle accidents caused by a drowsy driver occurred. Every three minutes there is a motor vehicle injury due to a drowsy driver; and within the next hour, there will be a traffic fatality attributed to a drowsy driver.
The Science of It
Even modest sleep loss over a week’s time (6 hours per night versus 7 ½ – 8 hours per night) can accumulate a sleep deficit that creates an irresistible tendency to fall asleep during any activity—including driving. If it happens to coincide with the natural dips in our alertness—such as early afternoon or late evening—the effects are compounded. Not surprisingly, that’s when most motor vehicle accidents occur.
Aside from the danger of flat-out falling asleep, sleep deprivation systematically erodes our physical and cognitive performance. Our reaction times and speed of thought are dulled.
In fact, studies show that 17 – 19 hours without sleep can impair performance equivalent to or worse than a blood alcohol concentration (BAC) of 0.05%! That means if you get up at 6:30 a.m., and are out driving at 11:30 p.m. that night, your reaction times could be impaired by as much as 50%.
More evidence of sleep’s role in highway safety can be found in statistics from the National Highway Traffic Safety Administration (NHTSA). They report that on the Monday following the switch to Daylight Saving Time in the spring—when nearly everyone loses an hour of sleep—our highways experience a 17% increase in traffic accidents compared to the preceding and following Mondays!
Sharing another consequence with alcohol, sleep deprivation not only creates a physical impairment but it is often accompanied by a lack of awareness of the impairment itself—we overestimate our abilities. “I’m fine” are often the last words we hear from a driver who’s had one-too-many drinks. Sleep deprivation seems to play the same trick on our good judgment resulting in unsafe behaviors.
Getting enough quality sleep plays a critical role in our overall health and well-being, including our safety. Strive to get 7 ½ – 8 hours of high quality sleep each and every night and don’t ignore those tell-tale signs of sleepiness. Sleep well!