"Most people think that sleepiness and drowsiness are only due to lack of sleep, but there are other factors that affect your levels of alertness throughout the day. These include staying awake for 16 hours or more, sleeping less than seven or eight hours a night, having interrupted sleep or suffering from an untreated sleep disorder such as obstructive sleep apnea," said President Sam Fleishman, MD, of the American Academy of Sleep Medicine (AASM).

"Fatigue and exhaustion can impair your performance even if you do not feel sleepy," he added. "As you become more fatigued, it becomes more difficult to pay attention and react quickly while driving."

According to a recent study by the AAA Foundation for Traffic Safety, an estimated 16.5 percent of all fatal motor vehicle crashes in the United States from 1999-2008 involved a fatigued driver.Studies have shown that the effects of sleep loss are similar to having a blood-alcohol content over the legal driving limit.

With family vacation season in high gear during the Independence Day holiday and continuing through Labor Day, AASM reminds drivers that being properly rested and fully alert is a responsibility owed to passengers and to others sharing the road. The AASM recommends these strategies for managing fatigue:

  1. Develop a healthy lifestyle by getting regular exercise, avoiding nicotine and eating plenty of fresh fruits and vegetables.
  2. Practice good sleep hygiene by following a regular sleep schedule and creating a comfortable sleep environment. Keep your bedroom dark, quiet and comfortably cool or warm. Limit food/liquid and alcohol intake, as well as electronic device usage before bedtime.
  3. For greatest effectiveness, use caffeine as needed – instead of daily – and use it in moderation.
  4. On longer road trips, use "activity breaks" to improve alertness. Pull over in a safe location and take 15-20 minutes to walk around and stretch.

Fleischman added that divers should not rely on turning the radio volume up, opening a window or chewing gum to try to stay alert. The only way to reverse fatigue and sleepiness is to get more sleep, he warned. And using illegal drugs or abusing prescription medication in order to fall asleep or stay awake is dangerous for your safety and health.

AASM has developed a free online presentation, “SAFE-D: Sleep, Alertness and Fatigue Education for Drivers.” The presentation also is on YouTube to share or embed.

The 30-minute narrated slide presentation explores the causes of fatigue, which stretch beyond the simple lack of sleep. For example, people who work outside of a typical nine-to-five schedule or work unpredictable schedules are at a high risk for fatigue. You can read more about sleep and sleep disorders on the American Academy of Sleep Medicine's "Your Sleep" Web site.