Under what conditions must a train not foul a highway crossing equipped with automatic warning devices?

A train must not foul a highway crossing equipped with automatic warning devices under all the specified conditions. Each condition represents a scenario where the train's movement could interfere with the safety of the crossing.

When making a reverse movement, it is essential to ensure that the train does not obstruct the highway crossing, as this could lead to a dangerous situation where vehicles are unable to pass safely while the train is present.

Approaching at restricted speed requires the train to be prepared to stop short of any obstruction, including highway crossings. This means that even at reduced speeds, the train must be vigilant in maintaining a safe distance from the crossing to ensure that no conflicts occur.

In the case of increasing speed in an approach circuit, if the train were to inadvertently enter the crossing area while accelerating, it could create a risk for vehicles on the highway. Therefore, maintaining a safe distance from the crossing is critical in this scenario as well.

Thus, under all these conditions—making a reverse movement, approaching at restricted speed, and increasing speed while approaching a circuit—a train must not foul the highway crossing to ensure the safety of both train operations and highway traffic.