How do drowsiness and fatigue affect driving?

Drowsiness and fatigue increase reaction time — the time that elapses from when the driver sees an obstacle to when they react. This time varies depending on the driver's psychophysical state, never due to speed or road conditions. The greater the reaction time, the greater the distance travelled. This distance also varies with speed — the higher the speed, the greater the reaction distance. The most important rules to avoid having an accident due to drowsiness or fatigue are: - If we feel tired or drowsy while driving, the most advisable thing is to stop and rest in a suitable place and sleep for about 20 or 30 minutes. - Rest for 20 to 30 minutes every 2 hours or every 200 kilometres at most. - Always be alert to the signs and symptoms of drowsiness or fatigue.