PROPOSAL OF NEW NOISE MAPPING PROCEDURES FOR NOISE ABATEMENT PLANS OF ROAD NETWORKS

In Europe the contents of Noise Action Plans of road networks are established by the Directive 2002/49/EC. In Italy another plan, the Noise Abatement Plan, is required by the national legislation, in particular by the Decree of the Ministry of the Environment of 29/11/2000. The procedures for the definition of both plans are quite similar and are based on the realization of noise maps. This paper analyses the effects of different methodologies used for noise mapping on the outcomes of the noise abatement plan of the road network managed by the Province of Terni in Italy. The road selected as case study is a single carriageway road that is 50 km long and passes nearby several sensitive receivers such as schools and hospitals. Four different methodologies were employed and the outcomes analysed. In particular in the first methodology a regular grid is used for calculations (Grid Noise Maps- GNM), while in the other ones the noise levels are evaluated at 1 meter from each building façade (Façade Noise maps – FNM). Moreover the latter three methodologies differ one from the other by the selection of the number and the position of the calculation points. The first two methodologies are in compliance with the Italian legislation while the other two are improvements developed and tested by the Authors that allow more realistic and accurate estimates of noise impact on the receivers. Usually the main outcome of an Italian noise abatement plan is the ranking of the buildings/areas that most urgently require mitigation and the definition of the anti-noise measures to be realized. The study shows how the different procedures affect these results and influence the activities of the managing authorities in the realization of the mitigation measures.