What do the numbers on permanent speed restriction signs indicate?

The numbers on permanent speed restriction signs specifically indicate the highest speed permitted over that section of track. This is critical for ensuring the safety and efficient movement of trains, allowing engineers to operate within the safe limits set for the track conditions. Permanent speed restrictions may arise from various factors such as track structure, curvature, or other physical considerations that require a reduction in speed to maintain safety.

This distinction is vital for train operation; knowing the maximum speed allows crews to ensure that they do not exceed this limit, which is essential for preventing derailments and ensuring the safety of both the train crew and the infrastructure.