Final answer:
The best action for a train operator when the train does not roll freely is to halt and check for any issues causing the immobility, prioritizing safety.
Step-by-step explanation:
If the train does not roll freely when the controller is moved to the first point and then shut off, the BEST course for the train operator is to stop moving and become stationary till it passes by.
This ensures safety for both the train and any nearby entities. The operator should investigate the cause of the issue, ensuring that there aren't any mechanical faults or obstructions that might be causing the train's lack of free movement.