Railway noise mapping after the application of CNOSSOS-EU: The case of Spain

European Directive 2002/49/EC requires EU Member States to produce strategic noise maps (SNMs) for major noise sources every five years. Initially, this directive prescribed the Dutch national calculation method (SRM II) as an interim method for railway noise mapping until a common EU calculation method was established. In Spain, in order to use this interim method, the Administrator of Railway Infrastructures (ADIF) developed guidelines for the application of the Dutch interim method and equivalence documents to adapt the Spanish train fleet to the Dutch categories. These mandates were used for the first three noise mapping rounds. From 31 December 2018, the CNOSSOS-EU method became mandatory for the preparation of MERs under Directive 2015/996. This change necessitated a revision of the ADIF guidelines to take into account the new method.This study analyses the consequences of the major change in the methodological framework, which has led to a distortion between the results obtained in different rounds due to the change from the Dutch SRM II method to the CNOSSOS-EU method for railway noise MER. The analysis shows that the discrepancies in the MER are not only caused by changes in the study scenarios in the different phases of the implementation of the Directive, but also by intrinsic differences between the two calculation methods. In the case of Spain, we also found discrepancies due to the variations in the ADIF application guidelines.