Every day, an estimated 83.6 million people in the U.S. drive drowsy. They’re taking a huge risk, as research shows that missing just two to three hours of sleep can more than quadruple a driver’s risk of a crash.

Fatigue poses such a danger to drivers that the National Highway Traffic Safety Administration (NHTSA) recently expanded its definition of impaired driving to include not only drunk, drugged, and distracted, but also drowsy driving. In 2017, the National Safety Council (NSC) declared fatigue as a “hidden but deadly epidemic”.

Fatigue-related collisions CAN be prevented by understanding the importance of adequate risk, the risk factors and the steps to take to avoid driving tired.

Why do we need sleep?

Failure to get enough sleep is directly linked to increased crash risk and research has also shown that it’s a threat to health. A lack of sleep is linked to several chronic diseases including diabetes, coronary heart disease and increased risk of stroke.

On a day-to-day basis, lack of sleep can impair the ability to think clearly and affect reaction time, attention, concentration and judgment. In fact, research shows it can affect driving ability as much as alcohol can.

Falling asleep at the wheel: the risk factors

Many factors can increase a person’s risk of falling asleep at the wheel, including:


  • Driving long distances
  • Driving through the night, or in the early afternoon (particularly after eating a large meal), or when you would usually be asleep
  • Taking medication that can cause drowsiness
  • Health conditions
  • Age—young people are more likely to stay up late, sleep too little, and drive at night
  • Diet, fitness, and lifestyle
  • Driving alone, particularly on long, monotonous roads
  • Drinking alcohol or taking drugs (including the evening before driving)
  • Having a hectic lifestyle—this can affect a person temporarily; for example, around the holidays, when juggling social occasions and work
  • Family and personal issues, such as a new baby in the family, money worries, relationship problems


  • Length of work shifts
  • Time of day
  • Lack of adequate rest periods
  • Volume of workload
  • Frequent traveling, particularly through different time zones

Planning trips to avoid fatigue:

  • Get a good night’s sleep before making a long trip
  • Factor in the natural body clock dips—during the night and early afternoon
  • Eat only light meals before driving
  • Take breaks of at least 15 minutes for every two hours of driving— these breaks should be used to relax, not catch up on other work
  • Get out of the vehicle to stretch and get some fresh air during breaks
  • Stay hydrated and eat sensibly during rest breaks
  • Keep the vehicle well-ventilated and at a comfortable temperature
  • Consider overnight accommodations or alternative transport where appropriate


  • Drinking alcohol before driving, including the evening before
  • Making long trips after a tiring day; for example, after being at a conference
  • Driving immediately after flying; and especially avoid driving after flying across time zones or overnight

Recognize the warning signs of fatigue

At times, you might be aware that you’re feeling tired and be able to pinpoint the reason, such as a new baby in the family. At other times, you might not realize how tired you are.

If you’re sleep deprived, the effects may become more noticeable when you’re driving, particularly on a long trip or at night. It’s important to be aware of the warning signs and to not ignore them. Common signs of being tired while driving include:

  • Difficulty concentrating
  • Yawning
  • Heavy eyes
  • Blinking more than usual
  • Neck muscles relaxing, causing the head to droop
  • Difficulty remembering the last few miles of a trip
  • Varying speed for no reason
  • Delayed reactions
  • Drifting in the lane

What to do if you feel tired while driving

It’s important not to rely on “quick-fix” solutions such as opening the window or having an energy drink. If you feel tired during a trip, an emergency step is to have a cup of coffee then take a “power nap” of 20 minutes. The effects of the caffeine and a brief sleep can increase alertness for a short period of time. Other emergency steps are:

  • Pull over and stop in a safe place—even if not due a break
  • Get some fresh air, get out of the vehicle, and move around
  • Perform some stretching exercises

Remember, these are emergency steps ONLY, not steps to be taken regularly in place of sleep. The only true cure for fatigue is sleep, everything else is a temporary countermeasure.

Learn more: The advice in this article is extracted from eDriving’s white paper Awake at the Wheel, designed to help fleet managers and drivers reduce the risk of fatigue-related crashes. Click here to download the guide for free.