Under what condition is driving at the posted speed limit considered even more dangerous?

Driving at the posted speed limit is considered even more dangerous under poor visibility conditions because reduced visibility can significantly impair a driver's ability to see obstacles, other vehicles, or changes in the road ahead. When visibility is compromised due to factors such as fog, rain, or darkness, drivers may not be able to react appropriately to potential hazards in time, regardless of whether they are obeying the speed limit.

In such situations, the risk of accidents increases because drivers cannot see the full range of their surroundings. This is why it's important to adjust speed according to visibility conditions; adhering to the posted speed limit might not take into account the driving challenges posed by low visibility, potentially leading to accidents or dangerous situations.

Good weather conditions and no other vehicles present may indicate that driving at the posted speed limit is safe, while high traffic areas often require more cautious driving, but neither of these factors directly highlights the risks associated with poor visibility.