During what condition must a train prepare to stop at a Working Limits Stop Sign?

A train must prepare to stop at a Working Limits Stop Sign unless it is confirmed to proceed without restriction because these signs are placed to ensure safety when work is being conducted on or near the tracks. The Working Limits Stop Sign indicates that the train must stop unless it has received clear confirmation from the appropriate authority that it can proceed safely without encountering any hazards or restrictions. This practice enhances safety by requiring trains to verify their travel permissions in areas where maintenance or mechanical work may create dangerous conditions.

In contrast, the other scenarios described relate to specific operational contexts, such as approaching interlocking limits, which focus more on signal aspects rather than work zones. Additionally, considerations about diversions onto affected tracks or approaching a terminal do not directly address the need for confirming safe passage in the context of working limits. Therefore, understanding the significance of confirming the ability to proceed without restriction is crucial for ensuring safe train operations in proximity to work zones.