What is required for a train to operate if auxiliary lights are inoperative?

When auxiliary lights are inoperative, the train is required to adhere to specific speed restrictions at grade crossings to ensure the safety of all involved. The stipulation to not exceed 20 mph over crossings is a precautionary measure. This slower speed allows for increased reaction time and lessens potential risk, as the auxiliary lights serve a crucial function in signaling the approach of a train to motorists and pedestrians. Their absence can lead to visibility issues, and the reduced speed helps mitigate the dangers that arise from that lack of visibility. It is a necessary operational adjustment that prioritizes safety in the absence of full signaling capabilities.

The other options involve actions that are either excessive or not applicable in this situation. For instance, requiring the train to stop at every crossing could significantly delay operations and is not a standard requirement for all situations where auxiliary lights are inoperative. Notifying the dispatcher is generally good practice, but it does not directly address the immediate operational limitations imposed by the absence of auxiliary lights. Returning to the yard immediately would not only disrupt the schedule but could also be impractical in many cases where trains need to continue operating under modified conditions.