What should be done to signals leading to an out-of-service track?

Setting signals leading to an out-of-service track to be applied with blocks is crucial for ensuring safety. When a track is designated as out-of-service, it means that the section is not available for train movements, either for maintenance or other reasons. By applying blocks to the signals, you are effectively communicating to train crews that they cannot proceed onto that track, thereby preventing any potential accidents or incidents.

This procedure is part of the overarching safety protocols that safeguard operations within the rail network. It minimizes the risk of trains accidentally routing into areas where they could encounter obstacles, maintenance personnel, or equipment. Other options would fail to provide the necessary visual warning or operational guidance to railroad personnel, thus increasing the likelihood of a safety breach.