When should a train's brake systems be at full capacity before departure?

A train's brake systems should be at full capacity before leaving the initial terminal because this is a crucial safety measure. Proper braking capability ensures that the train can respond effectively to any situation, such as needing to stop due to signals or unforeseen obstacles on the track. Conducting brake tests and inspections before departure helps confirm that the system functions as intended and can safely handle the weight of the train and any potential emergency scenarios. This practice is a standard aspect of train operation procedures and is key to ensuring the safety of the crew, passengers, and the public.

Other options suggest situations that may be important for safety or monitoring but do not emphasize the critical requirement of brake readiness before a train begins its journey from its starting point.