Ontario Class F Practice Test · Question
According to research on driver fatigue and circadian rhythms, at what time of day does the human body experience its natural lowest point of alertness?
Circadian rhythms are the body's natural internal clock that regulates the sleep-wake cycle. For commercial drivers, the strongest urge to sleep typically occur
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Question: According to research on driver fatigue and circadian rhythms, at what time of day does the human body experience its natural lowest point of alertness?
Answer options:
- Between 10:00 p.m. and 12:00 a.m. ✅ Between 2:00 a.m. and 6:00 a.m.
- Between 6:00 a.m. and 10:00 a.m.
- Immediately after eating a heavy meal at noon.
Correct answer: Between 2:00 a.m. and 6:00 a.m.
Explanation: Circadian rhythms are the body's natural internal clock that regulates the sleep-wake cycle. For commercial drivers, the strongest urge to sleep typically occurs between 2:00 a.m. and 6:00 a.m., and again in the mid-afternoon (2:00 p.m. to 4:00 p.m.). Awareness of these 'dips' in alertness is crucial for accident prevention.
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