As the rail is the main component responsible for the increase in SPL above 100 Hz near a steel bridge with a direct fastening system, rail dampers become a standard solution to reduce the noise.

• 在100赫兹之上，附直接紧固系统钢桥上路轨主要影响SPL的增量,路轨制音器成为降低噪声一个标准方案。