How can a train transition from Release mode into MCS mode?

A train can transition from Release mode into MCS (Movement Control System) mode while in motion because the system is designed to allow for seamless changes in operational modes that enhance efficiency and maintain safety. The ability to switch modes while the train is moving helps ensure minimal disruption to service and allows for better management of train operations.

Maintaining smooth transitions contributes to overall service reliability, allowing trains to operate efficiently within the rail network. This functionality is crucial in high-frequency rail systems where stopping the train for every transition would lead to delays and increased dwell times at stations.

Other options suggest conditions that are either overly restrictive or not required for the transition, which would not align with the operational design and efficiency of train systems like the PATH. Transitioning while in motion reflects the robust technology and operational protocols in place to ensure safety and effective train management.