According to the SEP 1 manual, what does evacuation mean?

Evacuation, as defined in the SEP 1 manual, specifically refers to the situation where passengers are discharged under unusual conditions that threaten their health or safety. This definition emphasizes the importance of prioritizing passenger safety during emergencies or hazardous situations. It reflects the protocols that conductors and other safety personnel must follow to ensure that passengers can exit a train or an area quickly and safely when they are in danger.

The other options describe scenarios involving passenger transfer due to various operational issues, such as annulments or lateness. While these may be part of train operations, they do not pertain to emergency situations or the immediate safety and health concerns that characterize an evacuation. Thus, the definition of evacuation focuses on the urgent need to protect passengers rather than routine operational procedures.