What is the significance of train signals?

Train signals are crucial as they communicate important information regarding track conditions and train operations. They provide essential directions to train operators, indicating whether they should proceed, slow down, or stop. Signals can indicate aspects such as track switches, blockages, and safety protocols, ultimately ensuring the safe and efficient movement of trains.

The other options don't capture the primary function of train signals. For example, while stopping for breaks might be part of a train operator's schedule, signals are not specifically designed for that purpose. Additionally, although signaling passengers on board is important, it does not pertain to the operational safety and management of trains. Similarly, displaying arrival times at stations is more relevant to passenger service information rather than the core function of train signals. Thus, the correct answer emphasizes the operational safety aspect of train signaling.