What atmospheric condition should trigger limitations on school bus operations?

The correct answer revolves around visibility, which is crucial for the safe operation of school buses. When visibility is reduced to 200 feet or less, it significantly increases the risk of accidents, as drivers may not be able to see other vehicles, pedestrians, or hazards on the road. This reduction in visibility can be caused by various environmental factors such as fog, heavy rain, or snow, making it imperative to impose restrictions on school bus operations to ensure the safety of the students and drivers.

The other conditions presented may also impact bus operations, but they do not necessarily trigger the same level of concern. For instance, while high wind speeds can be challenging, they are less critical than visibility in most contexts. Similarly, precipitation duration or low temperatures could lead to hazardous conditions, but they do not directly impede the ability to see and react while driving. Thus, reduced visibility stands out as the key factor warranting limitations in school bus operations.