What does the indication shown mean when it reads "proceed"?

The indication "proceed" typically signifies that a train is allowed to move forward, but there are often conditions attached to this signal that require careful attention. The choice indicating "with caution on main route" accurately reflects this notion. In rail operations, proceeding with caution is essential to ensure safety, particularly in situations where there could be obstacles, track conditions, or other operational factors to consider.

This term denotes that while the train may continue its journey, the operator should remain vigilant and be prepared to respond to any changes or instructions that might arise during transit. This cautious approach is a critical aspect of promoting safety and preventing accidents.

On the other hand, options suggesting that the train can operate at maximum speed without limits or that it can proceed immediately with no restrictions do not align with standard safety protocols in train operations. "Stop and wait for further instruction" also indicates a completely different scenario that does not match the context of the "proceed" indication.