How must on-track equipment approach bridges during unusually heavy rain or storms?

On-track equipment must approach bridges during unusually heavy rain or storms prepared to stop due to the potential for unsafe conditions. Heavy rain or storms can compromise the integrity of the bridge, including risks such as flooding, debris accumulation, erosion, or structural damage that may not be immediately visible.

By approaching the bridge prepared to stop, operators can ensure they are ready to react to any indications of unsafe conditions—whether it’s observing debris on the bridge, detecting changes in the bridge's behavior, or heeding signals indicating that the bridge may not be safe for passage. This cautious approach is crucial for maintaining safety and minimizing the risk of accidents or damage.

Other options, such as traveling fast for quick passage or at full speed, would significantly increase the risks involved, as they would not allow sufficient time to assess the conditions of the bridge or react to potential hazards.