Biologically, when are the worst times to drive due to fatigue?

The best understanding of fatigue in relation to driving times is rooted in the body's natural circadian rhythms, which can significantly impact alertness and energy levels. The correct choice identifies the periods of 12 a.m. to 5 a.m. and 1 p.m. to 3 p.m. as particularly risky times for drivers due to heightened fatigue.

During the early morning hours, specifically between midnight and 5 a.m., many individuals experience deep sleep, making it difficult for drivers to maintain alertness. This is often referred to as the "graveyard shift" time, when drivers are most likely to feel drowsy or fall asleep at the wheel.

The early afternoon period, from 1 p.m. to 3 p.m., is also known to be a time when people often experience a post-lunch dip in energy levels. This phenomenon can lead to decreased concentration and slower reaction times, increasing the risk of accidents.

Therefore, recognizing these two time frames as the worst for driving due to fatigue can help drivers plan their travel times more effectively, ensuring they are more alert behind the wheel.