What is the requirement for returning a main track switch to normal after a train passes?

Returning a main track switch to normal after a train passes involves safety protocols that ensure the switch is not repositioned until it is safe to do so. The requirement for the switch to remain out of position until cleared is crucial because it prevents potential accidents that could occur if another train were to approach the switch while it is not in its normal position.

By keeping the switch out of position until it is confirmed that the track is clear (meaning no other trains are approaching), train dispatchers minimize the risk of collisions or derailments. This procedure ensures that the main track remains secure for incoming trains, which is a fundamental aspect of safe train operations. Only after the area is deemed clear can the switch be safely returned to its normal position, maintaining the integrity of the rail system and ensuring the safety of all train movements.

Other options suggest either an immediate return of the switch at any time or relying on the presence of the next scheduled train, which does not prioritize the immediate safety requirements surrounding the switch position following the passage of a train.