Approximately how many crashes annually involve drowsiness and fatigue as a principal factor?

• A. 50,000
• B. 100,000
• C. 150,000
• D. 200,000

Answer: (B)

Fatigue and drowsiness directly impair driving ability by slowing your reaction time, reducing your awareness of hazards, and making it easier for you to drift out of your lane or miss signals. When sleep debt is heavy, you can even experience microsleeps—brief moments of sleep that last a few seconds—while still behind the wheel, which is enough to cause a crash.

Because fatigue isn’t always obvious to the driver or to police at the scene, researchers rely on surveys, testing, and crash reports to estimate its impact. The commonly cited figure is that roughly 100,000 crashes occur each year where drowsiness or fatigue is a main factor. This reflects the broad danger of driving when tired, especially on long trips, late-night drives, or after extended periods without adequate rest.

To reduce this risk, plan ahead for adequate sleep, take breaks every couple of hours on long drives, avoid driving during circadian low points (late night and early morning), and pull over to rest or nap if you start feeling sleepy.