What marks the mode change boundary for movement into Yard territory?

The mode change boundary for movement into Yard territory is marked by the front of the train entering Yard territory. This is due to the operational protocols that define the transition between different types of rail operations. In rail transportation, the movement into Yard territory signifies a shift in both the rules governing train operation and the type of track being utilized. When the front of the train crosses the threshold into Yard territory, it indicates that the train is now entering an area that has different operational rules, which are generally more focused on slower speeds and the handling of railcars for sorting and storage.

Recognizing this boundary is crucial for ensuring safety and proper adherence to operational procedures within railway operations. It ensures that the engineer can adjust the train's handling, speed, and prioritization in accordance with yard operations, where different rules apply compared to mainline track usage. Understanding this boundary helps engineers maintain safety and efficiency while transitioning operations from mainline to yard services.