When can a train leave a station according to the restrictions?

A train can leave a station when it can fully clear the platform. This ensures that all train operations are conducted safely and without endangering passengers or personnel who may still be in the vicinity of the platform. The requirement for the train to completely clear the platform before departure is crucial in preventing accidents, as it minimizes the risk of injury to individuals who may be close to the edge of the platform or attempting to board or disembark.

This condition not only aligns with safety protocols but also helps in maintaining the overall efficiency of train operations. By ensuring that the entire train has moved past the platform, it allows for the next train to safely approach, reducing delays and optimizing the flow of train schedules.

Other options, while they might hold some validity in different contexts, do not encapsulate the primary safety concern that governs train departures from stations. For example, waiting for the platform to be clear or having customers onboard does not specifically address the necessity of ensuring the train has completely vacated the area to avoid potential hazards.