What is a potential warning sign that a driver is becoming fatigued while driving?

A potential warning sign that a driver is becoming fatigued while driving is when their eyes close or go out of focus. This indicates that the driver is struggling to maintain alertness, which can lead to a dangerous situation on the road. When fatigue sets in, physical symptoms such as heavy eyelids, difficulty in focusing, or even micro-sleeps can occur, making it hard for the driver to react appropriately to changing conditions or obstacles.

Other choices suggest scenarios that would generally be associated with alert driving behavior. Feeling motivated to drive, increased speed, and clear concentration on the road typically reflect a driver who is engaged and responsive. In contrast, the inability to maintain focus is a clear signal of fatigue that should not be ignored, as it significantly heightens the risk of accidents.