When is it necessary for a train to stop before each public crossing when headlight and ditch lights fail?

A train is required to stop before each public crossing when headlight and ditch lights fail, unless the crossing gates are fully lowered. This requirement reflects safety protocols aimed at ensuring that trains can approach crossings where visibility might be impaired due to the failure of lights. The crossing gates serve as a physical barrier and provide a clear indication of whether the crossing is safe or active. If the gates are fully lowered, they indicate that the crossing is under control, and the train can proceed with caution. However, without functioning headlights and ditch lights, approaching the crossing without stopping could lead to dangerous scenarios, especially in low visibility or nighttime conditions.

The other scenarios, such as whether crossing gates are raised or whether high traffic is present, do not provide sufficient safety measures on their own to warrant that a train can proceed without stopping. Additionally, stopping only under low visibility conditions does not encompass the full range of safety considerations that are required when the train's lights are non-functional. It is essential for the train to stop to assess the situation and ensure the crossing is clear, which is why the specified condition regarding crossing gates is critical.