The oretical calculations and experimental studies at home and abroad have shown that the irregularity of the track is the main cause of vibration on the line of the locomotive. On the other hand, the track irregularity is the main source of the wheel-rail force. On the other hand, the short-wave surface of the track surface is not smooth. The resulting intense wheel-rail interaction may also cause rail and axle breakage, resulting in a vicious derailment accident.

It can be seen that strict control of the geometric shape of the railway track is of great significance for ensuring the safety, stability and comfort of the train operation, and is also a distinctive feature of the railway track structure which is different from other engineering structures.