What are the signals used at congested stations to allow a train to approach the one ahead called?

The term used to describe the signals at congested stations that allow a train to approach the one ahead is "Approach signals." These signals are designed to convey to the train operator that they can proceed with caution towards the next signal or the train ahead, as it indicates that the following signal is not at a stop position. Approach signals can help manage train spacing in busy areas, allowing for efficient movement while ensuring safety.

While other signals serve different functions, they do not specifically indicate this cautious advancement towards another train. Hold signals might prevent a train from entering a certain area, stop signals indicate that a train must halt, and close signals do not have a standard definition in the context of train operations. Understanding approach signals and their role in maintaining safe operations at congested stations is crucial for effective train management.