Drowsy Driving - Prevention and Countermeasures

Modern cars are too nice and comfortable and quiet.  They make driving to easy and promote drowsiness.  Ergonomic seats increases risk.  There are fewer drowsy driving crashes on don't drive drowsyurban roads than on rural roads.  Monotonous roadways facilitate sleepiness but do not cause it.

According to the National Highway Traffic Safety Administration (NHTSA) approximately 100,000 crashes a year are caused by drowsy driving in the US alone. Approximately 71,000 people are injured annually as a result of drowsy driving. Sadly, 1,500 die. The federal government's "Healthy People" initiative aims to reduce the rate of car crashes due to sleepiness per 100 million miles traveled from 2.7 to 2.1 by 2020.

In some respects drowsy driving is very much like drunk driving. When it comes to drunk driving, once someone has a blood alcohol level over .08, they are considered legally drunk. Studies have shown that a driver who has gone a day without sleep is very similar to a driver with a blood alcohol level of 0.10%, well above the legal limit.

Most car crashes in the United States do not involve alcohol. Most people in car crashes are wearing seat belts. While awareness of the dangers of alcohol and the need to buckle-up are important, drowsy driving remains an underappreciated danger.  At Sleepdex, we want to encourage more attention to this hazard.

Even accidents that are not explicitly reported as sleep-related may be influenced by drowsiness. An academic study found the "rate of non-sleep ascribed accidents is closely related with sleep propensity."


If there is a situation that could lead to a crash, such as a vehicle that has stalled in the middle of a highway, which one of these situations is the most dangerous?

Driver 1 – An alert, sober driver who notices the vehicle at the last minute, slams on the brakes, and has a mild to moderate impact with the stopped car, if any.

Driver 2 – An intoxicated driver whose reactions are impaired by alcohol. They recognize the stopped car, but their reflexes are too slow to react. While the driver takes their foot off the gas pedal they are barely hitting the brake when they hit the stopped car leading to a serious collision.

Driver 3 – A drowsy driver who has fallen asleep at the wheel. They have no knowledge that a car has stopped in front of them, and do not react until they crash into the vehicle, their foot still on the gas pedal.

By far, the most serious wrecks are those caused by drowsy drivers, because there is often little to no attempt to avert the accident.  Police investigators often notice the absence of skid marks or other signs of braking as evidence of microsleep.  The common description of someone being in a “trance” is a way of saying someone is in microsleep.


Unfortunately, many people do not look upon drowsy driving as a serious problem. Chances are you can think of a number of times that you were a little groggy or downright exhausted but got behind the wheel thinking it was alright. But if you’d had too many drinks and knew you were intoxicated, you probably would have handed your keys to someone else to help you get home safely.  Why do you choose to be safe in one case and not the other?

“Road has got me hypnotized” - "Radar Love" by Golden Earring.

It’s no surprise there are so many drowsy driving incidents when you consider the number of people who get behind the wheel when they are tired. 51 percent of drivers say in the past year they have experienced feeling sleepy while driving. 17 percent admit having actually fallen asleep at the wheel.  The circadian cycle is a harsh taskmaster.  Most drowsy driving accidents happen between 2 AM and 6 AM.

Fighting It 

How to counter drowsy driving?  Radio?  Rolling down the window?  Setting the cell phone alarm to remind you to check your drowsiness level on the road?  These might work.  Some new cars are coming out with intelligent systems for alerting drowsy drivers.


Related: Regulations

DrowsyDriving.Org - Learn the signs of drowsy driving and countermeasures you can take to avoid excessive risk from driving while sleepy. From the National Sleep Foundation.

Changing Behaviors to Prevent Drowsy Driving and Promote Traffic Safety: Review of Proven, Promising, and Unproven Techniques - From the American Automobile Association

Cornell University's Brake for Sleep

National Highway Traffic Safety Administration

Drowsy Driving Still Underappreciated

Countermeasures to drowsy driving

Responsibility and the drowsy driver

Sleep among shift workers


In Colorado, a couple companies have teamed in an interesting initiative to reduce the effects of apnea among truck drivers. The “Unite to Treat Sleep Apnea” program uses mobile diagnostic units loaded on trailers to get to the truckers and test them. The purpose is to let drivers know they have apnea and ways they can treat it so as to avoid drowsy driving incidents.

Related: Pilot fatigue is a significant problem in both civilian and military aviation operations. Statistics indicate that fatigue is involved in 4–8% of aviation mishaps. That's why the regulatory bodies such as the Federal Aviation Administration have put in rules limiting flight hours and ensuring minimal periods of crew rest.

Scheduling factors, sleep deprivation, circadian disruptions, and extended duty periods continue to challenge the alertness and performance levels of both short-haul and long-haul pilots and crews.


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