During which situation should a train operator stop and call the Control Center immediately?

A train operator must stop and call the Control Center immediately when receiving a stop signal and observing unusual activity. This scenario indicates a potentially serious safety concern that requires immediate attention. A stop signal generally instructs the operator to halt the train to avoid possible collisions or other dangers on the track. Unusual activity could include anything from unauthorized personnel on the tracks, equipment malfunctions, or even erratic behavior from other trains. Reporting this situation promptly allows the Control Center to assess the risk, coordinate a response, and ensure the safety of the train crew and passengers, as well as any personnel on the tracks.

In contrast, passing stationary trains, experiencing delays, or moving through a yard area typically do not necessitate immediate contact with the Control Center unless there are accompanying unusual conditions. These situations can often be managed according to standard operating procedures without the need for an immediate stop and report.