Under what condition may trains run with the current of traffic on designated tracks?

Trains may run with the current of traffic on designated tracks when a controlled signal indicates proceed. This is crucial because a controlled signal provides the necessary authorization and safety assurance for the train to proceed in that direction. The signal system is designed to manage train movements and ensure that trains operate safely and efficiently within the rail network.

The indication from a controlled signal confirms that the track ahead is clear and that it is safe for the train to continue its journey in the direction indicated, aligning with established safety protocols. This ensures that train operations are coordinated and helps prevent accidents that could occur if a train were to move without proper authorization or against the flow of traffic without the necessary clearance.