What happens when a train reports passing a station to the dispatcher?

When a train reports passing a station to the dispatcher, track authority is voided up to that point. This is essential for maintaining proper train movements and ensuring safety on the railway. By voiding the track authority, the dispatcher can accurately account for the train's position and understand that the specific segment of track is no longer occupied by that train. This allows the dispatcher to manage other trains accordingly and ensures that the movement of trains is conducted safely, preventing possible conflicts or collisions on the track.

This process is critical for operational integrity, and it helps to facilitate the movement of trains throughout the network by ensuring that the track is clear for subsequent movements. It effectively updates the system about the train's current location and allows for efficient coordination of rail traffic.