Under what circumstances should a driver reduce speed below the posted speed limit?

Reducing speed below the posted speed limit is crucial in specific circumstances to ensure safety and control. Adverse weather conditions, such as rain, snow, fog, or ice, can significantly diminish visibility and road traction, making it necessary to slow down to maintain control of the vehicle. Similarly, approaching intersections may require a reduction in speed, as these areas often present hazards from other vehicles, pedestrians, or obstacles, demanding increased caution.

Driving at or above the posted speed limit under such conditions can lead to accidents, as it may not allow enough time to react to sudden changes in traffic or road conditions. This aligns with safe driving practices, which prioritize situational awareness and the ability to respond effectively to various driving environments.