What does the caution signal instruct the train operator to do?

The caution signal instructs the train operator to proceed with caution, which means to continue at a reduced speed and be prepared for potential hazards or changes in conditions. This signal is typically used in situations where the track may not be clear or where the train operator needs to be aware of something that requires vigilance, such as a nearby train, a change in track conditions, or an upcoming stop.

Taking this approach allows the operator to maintain the safe operation of the train while being mindful of their surroundings and prepared to react appropriately if the situation changes. The significance of this instruction lies in its emphasis on safety and vigilance rather than immediate stopping or acceleration, which would not be suitable for a cautious approach.