What does a Yellow over Green signal indicate in train operations?

A Yellow over Green signal in train operations indicates that a train is allowed to proceed on the main route but must be prepared to stop at the next signal. This signal is a caution that while the train can continue its journey, it should be alert to the possibility of encountering another signal that may require stopping.

The yellow aspect serves as a warning that there could be a restriction ahead, while the green aspect signifies that the main route is clear at that moment. Understanding this signal is crucial for maintaining safety and ensuring that train operators remain vigilant, as the conditions can change quickly as they approach the next signal. Familiarity with these signals is essential for effective train routing and operational safety.