What is a common sign of driver fatigue?

Difficulty focusing and frequent yawning are indeed common signs of driver fatigue. Fatigue can impair an individual's cognitive functions, including attention and concentration, leading to challenges in focusing on the road and surrounding conditions. Yawning frequently is a physiological response indicating tiredness and a need for rest. When drivers experience these symptoms, they are at a higher risk of making poor decisions or having slower reaction times, which can significantly increase the likelihood of accidents.

In contrast, increased speed while driving generally indicates that a driver is alert but possibly engaging in risky behavior. Constantly changing lanes might reflect aggression or distraction rather than fatigue. Listening to loud music can be a way some drivers attempt to stay awake, but it does not directly indicate fatigue and can sometimes lead to further distractions.