Most people think of drowsiness as a mild annoyance, not as something that could put them and others’ lives at risk. However, when it comes to getting behind the wheel, drowsiness is not far behind known dangers such as intoxication and distraction in terms of the risks it poses.
A recent study that used dashcam footage to analyze drivers’ facial expressions in the time leading up to a crash concluded 9.5 percent of motor vehicle accidents include drowsiness as a factor. This data confirms the suspicion of many safety researchers that incidences of drowsiness that lead to a crash are under-reported, since self-reporting is often the only way to know if a driver was sleepy; unlike drugs and alcohol, a lack of sleep does not show up on a chemical test.
How lack of sleep affects driving
While extreme levels of sleep deprivation can cause serious symptoms such as hallucinations, it takes a far lesser degree of undersleeping to affect driving safety. Missing out on as little as two out of the recommended eight nightly hours of sleep can slow reflexes, increase distraction and blunt judgment. Long before a driver actually begins nodding off, his or her driving becomes increasingly risky.
Knowing the warning signs
Many drivers know to stay off the road when they find themselves falling asleep. However, the time to stop driving (or decide not to get behind the wheel) is when one first notices warning signs such as frequent yawning, heavy eyelids or difficulty focusing. Most importantly, you should know your own patterns. Some people segue abruptly from feeling fully alert to complete exhaustion. The bottom line is, if you know you did not get enough sleep, avoid driving.
What makes drowsiness more likely
Some factors can increase the risk of drowsiness. These may include taking certain medications or driving at a time when you would normally be asleep. For some people, even tiny amounts of alcohol well below the legal limit can impair driving ability. Conditions such as sleep apnea can also lead to drowsiness. If you get eight hours of sleep every night yet somehow do not feel rested, you may need to seek medical attention.