Under what condition may a train operator start to enter a station when held by a red signal?

A train operator is allowed to start entering a station when held by a red signal if the leaving automatic signal has changed to yellow. This is a key safety procedure that ensures that the operator receives proper indication to proceed. The yellow signal indicates that the operator may approach the next signal with caution, confirming that it is safe to enter the station as they prepare for either a stop or the next phase of their journey.

This protocol helps maintain safety and prevents potential accidents that could occur if a train were to proceed without proper clearance. It is designed to ensure that the operator is aware of any conditions or issues ahead that may affect their ability to safely enter the station.

In contrast, the other conditions would not necessarily warrant proceeding into the station under a red signal. Disembarking passengers or a hand signal from the station master does not provide the necessary signal indication to safely enter. Red signals are explicit indications that the track ahead is not clear, and proceeding under those conditions could lead to dangerous situations. Therefore, the only correct condition under which a train operator can start entering a station from a red signal is when the leaving automatic signal has turned yellow.