What is the effect of fatigue on driving performance?

Fatigue significantly impairs driving performance due to its effects on both cognitive and physical functions. When a driver is tired, their reaction time is generally slower, making it harder to respond promptly to unexpected situations on the road. This delay can lead to serious safety risks, as timely reactions are crucial for avoiding accidents.

Furthermore, fatigue can impair judgment. A tired driver may not make the best decisions regarding speed, lane changes, or adherence to traffic rules, which directly impacts overall driving safety. Slower reflexes compound these issues, making it even more difficult to execute necessary maneuvers in a timely manner.

The other options do not accurately reflect the detrimental effects of fatigue. For example, fatigue does not lead to improved judgment or faster reflexes, nor does it leave driving ability unaffected. Instead, the clear consensus from research is that fatigued drivers experience significant impairments, making option B the accurate description of fatigue's impact on driving performance.