If a signal changes from proceed to stop, is the train required to stop immediately?

When a signal changes from proceed to stop, it is imperative for the train to stop immediately. This is a critical safety protocol in railway operations, as a stop signal indicates that the train must halt due to potential dangers ahead, such as another train on the same track or an obstruction. Stopping immediately allows for the situation to be assessed and ensures the safety of both the train crew and passengers. Additionally, reporting the change is crucial for effective communication and coordination among the train crews and dispatchers, allowing for timely updates on track conditions and facilitating necessary action following the signal change. This adherence to protocol is vital in preventing accidents and maintaining the safety integrity of train operations.