Who must communicate signals affecting the movement of the train?

The correct answer is that qualified employees on the leading engine or car must communicate signals affecting the movement of the train. This is in alignment with operational protocols that ensure effective and timely communication of critical information that influences train movement. The leading engine or car typically houses key personnel who are responsible for monitoring the train's progression and responding to signals, which are crucial for maintaining safety and proper operation.

Qualified employees are trained to understand and interpret signals reliably, making them the most appropriate individuals to relay information regarding changes in movement restrictions or authorizations. This requirement minimizes the chances of miscommunication and ensures that all operational directives are followed with the utmost attention to safety.

Other roles, such as the conductor and engineer, play significant parts in train operations, but the protocol specifically places the responsibility for communicating signals with those who are positioned where they can best observe and assess the necessary signals affecting train movement. This strategic placement aims to enhance operational efficiency and safety on the rail network.