On single track where rule 251 is in effect, what must inferior trains do?

When Rule 251 is in effect on single track, it is important for inferior trains to clear the time and block of opposing regular trains. This rule is established to ensure the safe and efficient movement of trains on single track stretches, where two trains cannot occupy the same segment of track at the same time.

Under this rule, an inferior train, which is designated by its schedule or operation as having lesser priority compared to the regular train, is required to take necessary actions to allow the opposing regular train to pass unhindered. This means the inferior train must clear the block and time as defined by the timetable and any applicable signals, ensuring the safe passage of the higher-priority train.

This requirement is crucial for maintaining operational flow and preventing potential collisions, ensuring a standard practice that enhances safety and service reliability on the rail network. Other options, while they may involve some operational considerations, do not reflect the specific requirement set forth by Rule 251, which emphasizes the priority of maintaining clear blocks for opposing movements.