With the recent media push raising awareness of distracted driving, and the generation-long fight against impaired driving, perhaps the dangers of drowsy driving are under-represented. Certainly a tired driver behind the wheel exhibits traits of both distraction and impairment. Driving while tired can have effects similar to a blood alcohol level of up to 0.20, four times the legal limit.

Effects of Fatigue

Sleepiness has a number of effects on both mind and body. In particular, a fatigued driver experiences:

  • Slowed reaction time
  • Reduced judgement
  • Compromised vision
  • Reduced thought processing and short-term memory
  • Elevated aggressiveness

Determining Sleep-Related Accidents

Accidents caused by tiredness are hard to identify precisely. Usually, cause is implied by evidence at the crash site. However, if the accident is fatal or the driver doesn’t admit to being tired, doubt remains.

Drowsy drivers are more likely to be in single-vehicle accidents. Skid marks are either absent altogether or occur after the vehicle was already in trouble. Often the accidents result in serious injury or death since the driver took no action to slow the vehicle or avoid collision.

Causes of Tiredness

Drowsy driving

Drowsy driving is not simply a matter of being on the road past your bedtime. Sleep disorders, both moderate and severe, may contribute at any time of the day. Changing sleep cycles during a road trip, for example, can cause unexpected tiredness, depending on how much natural circadian rhythms are disrupted. Prescription drug use may cause drowsiness, even if this is not normally a side effect of the medication. Stress, too, may have unpredictable effects including unexpected fatigue.

A 2012 study by the American Automobile Association found that almost 60 percent of drivers who reported falling asleep did so while in the car less than an hour. Drivers in the car three or more hours reported only a 20-percent rate. Fully a quarter of those surveyed said sleep incidents happened between noon and 5 p.m.

Preventing Sleep-Related Accidents

First and foremost, know the warning signs:

  • Frequent blinking and irritated eyes
  • Daydreaming and wandering thoughts
  • Heavy head
  • Increased drifting into oncoming lanes or median rumble strips
  • Missed traffic signals, signs or highway exits
  • Increased yawning

Improved Driving Wakefulness

  • Get off the road when you detect any warning sign. Find a safe area and rest for 15 to 20 minutes. Get out of the car and stretch following this. Repeat whenever the warning signs begin again.
  • Don’t drive alone. Driving with another person can help keep you alert, and they can spot fatigue warning signs as well.
  • Make a Tim Horton’s stop. A large double-double can give you a boost for an hour or two.
  • Have a Plan B. If you’re planning a trip where drowsiness is possible, have a worst-case backup plan. Know where motels and rest stops are along the way, in case sleep is unavoidable.