DEKRA experts: fatigue at the wheel is often underestimated

The silent danger at the wheel: microsleep without an accident is a matter of luck

Oct 25, 2024 Safety on the road
  • Recommendation: take a break every two hours
  • A power nap and a short walk around will do more than a coffee
  • Fatigue warning system mandatory in new vehicles in the EU

Being tired at the wheel poses an acute risk of accident. The accident experts at DEKRA warn against underestimating the risks. “Anyone who gets behind the wheel when they are tired and continues driving despite symptoms such as frequent yawning or a waning ability to concentrate is putting themselves and others at risk,” warns accident researcher Markus Egelhaaf.

“If you doze off for just one second at a speed of 65 mph, you'll cover almost 100 feet while 'driving blind'. And if you snooze for three seconds, you'll cover more than 100 yards. “During that time, the car is out of control, and it's pure luck if it doesn't crash,” says the accident researcher.
According to a study of the AAA Foundation for Traffic Safety, an estimated 17.6% of all fatal crashes in the United States in 2017–2021 involved a drowsy driver. Over the 5 year study period, an estimated 29,834 people were killed in crashes that involved drowsy drivers. For Germany, the official 2023 crash statistics state fatigue as the cause of 1,902 traffic accidents resulting in personal injury. 3,010 people were injured, 42 of them fatally. However, accident experts assume that the number of unreported cases is much higher, since drivers often do not admit to being overtired or it cannot be proven.

“Dark season” makes you tired

In the “dark season”, fatigue can more easily gain the upper hand when driving, warns accident researcher Egelhaaf. “Anyone who drives longer into twilight or darkness after a strenuous day will find it more difficult to maintain concentration, especially if they are on monotonous freeway sections.” People who sleep only briefly or poorly at night are also more likely to fall victim to fatigue.

Power naps and movement instead of coffee

It is always dangerous when the typical symptoms of fatigue set in: yawning can hardly be suppressed, concentration diminishes, eyes fall shut, you have difficulty staying in your lane, or you have no memory of the route you have just traveled. “These are clear signs that it is time to stop as soon as possible and take a break,” emphasizes Egelhaaf.
“It's best to get some real sleep. A ‘power nap’ of 15 to 20 minutes followed by a short exercise program in the fresh air is more effective than the typical pick-me-ups like coffee or energy drinks. They only keep you awake for a short time,” says the accident researcher. “It should also be noted that, as restful as power naps may be at the moment, they cannot replace regular sleep at night.” You also need to be careful with food: a full stomach can make you sleepy. Light food is therefore preferable. Mineral water or juice spritzer are recommended drinks.

Take a break every two hours

As a rule of thumb, it is time to take a break after two hours behind the wheel at the latest, even if you still feel reasonably fit. “This is where personal responsibility comes into play for everyone. After all, it is about your own safety and that of other road users,” emphasizes DEKRA accident researcher Egelhaaf. Anyone who gets behind the wheel when unfit to drive can also be liable to prosecution, depending on national laws and regulations.

Drowsiness warning system mandatory in new vehicles

Many car manufacturers have been offering a technical solution for some time now in the form of a drowsiness warning system that helps to prevent microsleep at the wheel. Since July 2024, such systems are mandatory in all new vehicles in the EU. They collect data such as driving behavior, lane keeping, eye movements or blinking, driving duration and speed. If the fatigue warning system detects signs of fatigue, it issues a warning, for example with an audible signal or a visual signal (“coffee cup”) on the display. This means taking a break for safety – the DEKRA experts strongly advise not to take such warnings lightly.