How will movements enter the In-Service portion of a track?

The correct answer reflects the established protocol for entering the In-Service portion of a track. Movements typically require permission from the Dispatcher, as this individual is responsible for managing train movements and ensuring that they comply with safety regulations. The Dispatcher has the authority to provide the necessary clearance and determine when a train is allowed to enter a section of track that is in service, which helps prevent accidents and ensure the orderly flow of rail traffic.

In this context, verbal approvals from the crew or a first-come, first-served basis are not standard practices because they could compromise safety and coordination by allowing multiple trains to enter the same segment of track without appropriate checks. Automatic clearance when the track is cleared also lacks the necessary oversight and safety checks that the Dispatcher provides, which are crucial for maintaining safe operations within rail networks. Therefore, permission from the Dispatcher is vital to ensure all movements onto the track are controlled, organized, and safe.