The time period when drivers are most at risk of driving while drowsy is __________.

Drivers are most at risk of driving while drowsy during the time period from 12AM to 6AM. This timeframe corresponds to the natural sleep patterns of most individuals, where fatigue is at its peak. During the late night and early morning hours, the body's circadian rhythm typically signals a time for rest, making it more likely for individuals to feel sleepy or drowsy.

Driving during these hours poses significant risks because a drowsy driver may experience reduced attention, slower reaction times, and impaired decision-making abilities, similar to the effects of driving under the influence of alcohol. Awareness of these vulnerable hours is critical for promoting safe driving practices and preventing accidents related to drowsiness.