A simplified approach for evaluating noise impact from high-speed lines

Sweden is now considering new railway lines typically adapted to high speeds up to 320 km/h. Noise impact from high-speed lines and noise mitigation measures where required becomes urgent to be investigated. As the current calculation model for railway noise used in Sweden is not applicable for the purpose, the Swedish Transport Administration decides to prepare a new noise assessment method for high-speed lines. This new noise assessment method is not necessary to be comprehensive because noise evaluation along high-speed lines is mainly oriented. In this paper a simplified source module is described. The simplification has three folds of meanings: (1) only dominant noise sources, rolling noise and aerodynamic noise, are considered; (2) a classification of train types is made based on noise emission strength, not on the physical parameters; (3) the effect of noise measures (such as rail/wheel dampers, sleeper pads or mats, wheel skirts, etc.) is integrated into a single parameter, additional noise reduction (given either in total level or in spectrum). Moreover, the effect of noise barriers along a high-speed line is left to be handled by the sound propagation module.