What does the indication of the illuminated sign shown signify during operations?

The indication of the illuminated sign during operations typically signifies the beginning of time control at the indicated speed. This means that operators are required to adhere to specific time intervals while traveling at the speed shown on the sign. This control is crucial for maintaining safe train operations, scheduling adherence, and overall efficiency on the rail network.

Time control helps manage the flow of traffic, ensuring that trains are spaced appropriately apart to prevent congestion and allow for safe travel. By indicating a specific speed to be maintained, it aids operators in achieving the necessary timeframes for their journeys, thereby supporting both punctuality and safety during operations.