Under the Influence of Sleep Deprivation: How Early School Start Times Put Teen Drivers at Risk

Safe driving organizations target teens with advertising and special programs designed to spell out the dangers of drunk driving. What many people do not know is that there is another type of impairment that has nothing to do with alcohol. Driving while drowsy is the third leading cause of car crashes in the United States, but it does not get as much attention as it should. Schools are directly contributing to this problem by forcing teen drivers to wake up very early in the morning, at a time when they actually need more sleep than they did as young children. Sleep deprivation increases the risk of accidents by impairing decision-making skills and slowing reaction times, putting teen drivers in very real danger.

Sleep Deprivation: The Shocking Truth

Researchers from the University of Bologna in Italy conducted a study to determine the effects of sleepiness on adolescent motor vehicle accidents. They determined that adolescent drivers were twice as likely to have an accident if they drove while experiencing sleepiness. The increased risk also applied to teen drivers who reported getting inadequate sleep before driving. Twenty-three percent of the students had already had one accident, with 15 percent of those teens attributing their crashes to sleepiness. The lead author of the study, Dr. Fabio Cirignotta, says that blasting the radio, drinking caffeinated beverages and opening the window are essentially useless when it comes to counteracting the effects of drowsiness on teen drivers. He says the only way to counteract drowsiness is to pull over in a safe place and take a nap for at least 10 minutes. Unfortunately, American teens cannot follow this advice, or they risk getting in trouble for tardiness at school.

Startling Statistics on Sleep Deprivation

Don't Drive Sleep Deprived

Don't Drive Sleep Deprived

In a Today Show segment, experts discussed the issue of drowsiness and teen driving. Thomas J. Balkin, Ph.D., chairman of the National Sleep Foundation, told the interviewer that driving while drowsy is similar to driving while under the influence of alcohol or drugs. Drowsiness impairs the judgment, alertness, awareness and reflexes of teen drivers. Fifty-one percent of adolescents who responded to the 2006 National Sleep Foundation Sleep in America poll said that they had driven while drowsy at least once within the previous year. Five percent of these adolescents reported falling asleep or nodding off while driving during the same time period. Twenty-seven percent of those adolescents reported having a near-miss or getting into an accident due to their drowsiness. Many people do not understand the seriousness of driving while drowsy. This is partially due to the lack of objective tests for sleepiness in a crash victim. When someone drives while intoxicated, blood and breath tests can determine that person’s level of impairment and help explain what caused the accident. When people drive drowsy, there is no way to determine their level of sleepiness. Additionally, most drivers experience hyperarousal immediately following a crash. This hyperarousal can eliminate any signs of impairment caused by sleepiness.

Characteristics of Crashes Related to Drowsiness

The National Highway Traffic Safety Administration indicates that crashes related to drowsiness usually have several characteristics in common. Crashes that occur when a driver falls asleep are usually very serious. This may be due to slowed reaction times in drowsy drivers. Most crashes related to drowsiness are also single-vehicle accidents. This means that the vehicle leaves the road without crashing into other vehicles. Many of these accidents take place on major roadways or highways that have speed limits of 55 to 65 MPH instead of city streets or roadways with lower speed limits. One way law enforcement officers determine if a crash was caused by sleepiness is looking for signs that the driver attempted to avoid crashing. If there are no ski marks or other signs of trying to avoid the crash, it is more likely that the accident was caused by driving while drowsy.

Impaired Reaction Times

Researchers from Brigham and Women’s Hospital, a Harvard affiliate, determined that chronic sleep loss causes a tenfold decrease in reaction time and increases the risk of motor vehicle accidents. Daniel A. Cohen of Harvard Medical School led the study, which followed nine volunteers following a sleep-wake schedule consisting of 10 hours of sleep and 33 hours of staying awake. The researchers tested each participant’s memory, motor skills, reflexes and other brain functions. In addition to finding out that lack of sleep impairs reaction times, the study investigators also found that one good night of sleep is not enough to make up for weeks of sleep deprivation. Cohen said that many students pull all-nighters when completing large projects or studying for midterms and final exams. These all-nighters increase the risk for accidents related to drowsiness.

Sleepiness increases the amount of time it takes for teens and adults to complete certain tasks. Teen drivers need to react quickly in many situations. Any time a teen driver encounters an unexpected obstacle in the road or has to react quickly to changing weather conditions, drowsiness makes it difficult to make good decisions. This puts teen drivers at risk for serious motor vehicle accidents.

Driving Contracts

Although parents cannot control school start times, they can help their teens reduce the risk of accidents caused by drowsy driving. Parents or other caregivers should make sleep a priority for their teens. Encouraging adolescents to finish their homework or come home from activities early can help ensure teens get to bed at a reasonable hour. Parents should also set a good example for their kids by not riding with people who are under the influence of drowsiness. Offering to pick up a teen or arrange for alternative transportation if someone is too sleepy to drive safely can help teens find the courage to turn down rides from tired friends. Setting consequences for driving while sleepy can also discourage teens from taking the wheel when they are tired or fatigued.

Teens have enough to worry about without putting themselves at risk for serious car crashes. Encourage your teen to get a good night’s sleep before driving to school each morning. If you notice that your teen seems sleepy or fatigued, suggest that you drive that morning. These small steps can help save your teen’s life.

About Leigh Ann Morgan

I write about all sorts of things but ever since I completely got rid of my constant neck pain by finding the perfect pillow, I've started to learn as much as I can about sleep quality and sleep disorders.


  1. Thanks for this article! I love the way you make such a direct connection between these very early –too early — start times and teen sleep deprivation. Also, I love this strong statement in the first paragraph:
    Schools are directly contributing to this problem by forcing teen drivers to wake up very early in the morning, at a time when they actually need more sleep than they did as young children. Sleep deprivation increases the risk of accidents by impairing decision-making skills and slowing reaction times, putting teen drivers in very real danger.

  2. This article does a great job showing why everyone care about the school start time issue: it affects us all, whether or not we have kids. My only quibble is the end of the article, which seems to shift the blame from the schools to the individual students and families. Yes, I understand the need to find a solution, even a halfhearted one, as well as the reality that we all have to do the best we can until schools make changes. But these solutions are unrealistic. Not only are many parents just as drowsy as teens at 6 am, but not all have the option to drive them to school. Also, sleep-deprived teens are drowsy all day long. We should ban them from driving altogether if we really want to get them off the road – but that’s another societal solution.

    Sometimes we have to admit that some problems simply can’t be solved by individuals. The only real answer may come from collective action on a national scale, as Harvard’s Nicholas Christakis and Erika Christakis argue so well in their Time Ideas article (http://ideas.time.com/2011/11/18/why-are-we-depriving-our-teens-of-sleep/). This is what we’re trying to do at StartSchoolLater.net, and through our petition for a minimum start time (http://bit.ly/tWa4dS).