How should a train proceed at a signal displaying a Stop and Proceed indication?

When a signal displays a Stop and Proceed indication, the correct action is to stop the train and then proceed at a restricted speed. This means that the conductor must first halt the train completely before continuing. The term "restricted speed" is crucial here, as it imposes a limitation on how quickly the train can move while ensuring safety.

Restricted speed allows the train to proceed in a manner that is safe considering potential obstructions, switches, or other trains that may be in the area. This approach ensures that the train can stop within half the distance it can see to be clear of any obstruction, effectively managing the risk of accidents that could occur if the train were to proceed at higher speeds.

The other choices do not align with the established protocol for handling Stop and Proceed signals. For instance, proceeding without stopping disregards essential safety practices. Similarly, stopping and proceeding at medium speed does not provide the safety buffer required for potential hazards. Lastly, while confirming with the control operator can be an important procedure in some contexts, the standard protocol for a Stop and Proceed signal does not depend on that confirmation but rather mandates an immediate stop followed by cautious movement.