How should trains approaching signals at the beginning of ABS territory behave?

When trains are approaching signals at the beginning of Automatic Block Signal (ABS) territory, they should approach cautiously and prepare to stop. This is crucial because the ABS system is designed to enhance safety by providing automatic signals that indicate the condition of the track ahead. By approaching cautiously, train crews can respond appropriately to any signals they encounter and ensure they can stop safely if needed.

This cautious approach enables the crew to react appropriately to various signal aspects, whether they indicate a stop, caution, or can proceed. A prepared mindset ensures that the train is ready to stop if a signal indicates that it is not safe to continue, thereby preventing potential accidents.

The other options do not align with safe operational practices in ABS territory. For instance, passing at normal speed could lead to unsafe conditions if a signal requires a stop. Relying solely on the dispatcher undermines the autonomous safety measures provided by the signal system. Additionally, the idea that trains should never stop at these signals disregards the fundamental purpose of signals, which is to control train movements based on track conditions. Thus, approaching signals cautiously and being prepared to stop is the appropriate and safest procedure.