What do block signals govern for trains on specified tracks?

Block signals are essential components of railway operations, as they provide visual indications to train crews regarding the status of the tracks ahead. They serve to enhance safety by informing train operators whether it is safe to proceed or if they need to stop due to different train movements.

When considering the function of block signals, it's important to recognize that they are designed to govern both opposing and following movements on specified tracks. This means that block signals provide critical information not only for trains following one another on the same track, avoiding collisions due to close spacing, but also for trains operating in the opposite direction. By controlling the flow of traffic in both directions, block signals play a vital role in maintaining orderly and safe train operations across multiple tracks.

In contrast, other options might suggest that block signals are limited in their function. For instance, only opposing movements or only following movements reflects a misunderstanding of the comprehensive role that block signals play in railway safety. Similarly, restricting the authority of block signals to merely siding tracks does not account for their broader application across main lines and other operational tracks. This holistic governance is crucial for effective train management and ensuring that the complexities of multiple train movements are safely and efficiently handled.