The indication "PROCEED with caution" should prompt a train operator to do what?

The indication "PROCEED with caution" is a directive that requires a train operator to exercise heightened vigilance and readiness to respond to potential hazards. Selecting to reduce speed and be prepared to stop aligns with the principle of caution, ensuring that the operator can react promptly should an unexpected situation arise, such as an obstacle on the tracks, signal changes, or other operational concerns. This approach prioritizes safety over maintaining or increasing speed, allowing the operator to manage the train effectively under cautious circumstances.

Maintaining current speed would not be appropriate, as it does not account for the signs of potential danger that the caution signal implies. Similarly, increasing speed goes against the cautionary nature of the indication, as it would reduce the operator’s ability to respond quickly to any issues. Coming to a complete stop could be overly conservative if the conditions do not warrant it, and it may cause unnecessary delays in operations. Therefore, the correct action under "PROCEED with caution" is to reduce speed and be ready to stop, ensuring safety and operational readiness in potentially hazardous situations.