Why must extreme care be used when operating in PASSENGER mode?

Operating in PASSENGER mode requires extreme care primarily because any movement of the automatic brake valve handle toward RELEASE will cause the brakes to release for the entire train. This is crucial to understand because a sudden or unintentional release of the brakes can lead to a variety of dangerous situations, especially when managing a train that may be carrying numerous passengers.

In this mode, the dynamics of train control are heightened, and the potential consequences of an abrupt brake release are significant. If the brakes are released too quickly, it can cause the train to accelerate unexpectedly, leading to safety hazards, including the risk of collisions or derailments, particularly at station stops or during maneuvers in crowded areas.

The other options, while relevant to train operations, do not encompass the critical safety concerns associated specifically with the operation of the automatic brake system in PASSENGER mode. Understanding this aspect is essential for safe and effective train handling, ensuring that operators remain vigilant and deliberate in their actions to maintain passenger safety.