The Dangers of Driver Fatigue

Have you ever “pulled an all-nighter” to study for exams or write a paper? Or perhaps you’ve sacrificed a good night’s sleep—crashing at 3 am—to watch the latest binge-worthy Netflix series? If so, you have experienced acute sleep deprivation, defined as a short period of time (usually two days or less) without any sleep or significantly less sleep than usual.

Well, everything in life has a price, including forfeiting sleep. It will cost you the next day in terms of some pretty unpleasant symptoms—excessive sleepiness, sluggishness, impaired concentration, slowed thinking, and mood changes (for example, cranky, stressed, irritable, anxious). Although these symptoms seem harmless, they can have deadly consequences when you get behind the wheel.

Fatigued driving can result in the same fatal consequences as driving drunk. Research shows that being awake for 18 hours can result in cognitive impairment roughly equal to having a blood alcohol concentration of .05%. After 24 hours without sleep, the level of cognitive impairment approximates a BAC of .10%--over the legal limit in Ontario.

Transport Canada says driver fatigue is responsible for about 20% of fatal collisions. Moreover, a public poll by the Traffic Injury Research Foundation found that 60% of Ontario drivers admitted to driving when fatigued at least sometimes, and 15% of Ontario drivers (over a million drivers) reported falling asleep or nodding off when driving.

Importantly, falling asleep isn’t the only risk factor when it comes to fatigued driving. A more common experience is a “microsleep,” in which the eyelid partially or fully closes for just a few seconds, says neuroscientist and sleep specialist Matthew Walker. Microsleeps are more commonly experienced by chronically sleep-deprived individuals (i.e., those who routinely get less than seven hours of sleep a night).

During a microsleep, “your brain becomes blind to the outside world for a brief moment – and not just the visual domain, but in all channels of perception,” explains Dr. Walker. When this happens, you have momentarily lost the ability to control motor actions such as steering and braking. During a microsleep of only two or three seconds, your vehicle can drift into oncoming traffic or go off the road, with potentially fatal consequences.

Young Drivers of Canada refer to drowsy driving as “one of the four Ds—drunk, drugged, distracted, and drowsy—of impaired driving that has received the least public attention.” Most of us can probably recall safety campaigns targeting impaired or distracted driving. But could we say the same about fatigued driving?