Which factor is known to impact a driver's reaction time?

Fatigue is a significant factor that impacts a driver's reaction time. When a driver is fatigued, their cognitive functions and physical capabilities are diminished, leading to slower decision-making and delayed physical responses. This can result in a lack of alertness, impaired judgment, and slower reflexes, all of which are critical for safe driving. When a driver becomes tired, they may not react quickly enough to sudden changes in the driving environment, such as the appearance of an obstacle or the need to brake suddenly. Recognizing and addressing fatigue is crucial for maintaining heightened awareness and responsiveness while driving, thereby reducing the risk of accidents.