Patania F., Gagliano A., Nocera F., Galesi A.

With reference to noise pollution, Italian policy shows two specific supervisory regulations: -the Legislative Decree of Prime Minister (D.P.C.M.) 01.03.1991 on the highest limit of exposure to noise both in indoor and outdoor environments; -the Legislative Decree of President of Republic (D.P.R.) 18.11.1998 n°459, complied with Directive 25.06.2002 of European Parliament, which dictates executive rules on noise pollution coming from railway sources. On this ground people carried out an applied research to verify the observance of previous laws in some zones of Catania crossed or bounded by railway lines and in this way the paper wants to show both the results of research and some interesting consideration coming from the analysis of results. People carried out research through the following steps: -analysis of more significant noise sources of railway system; -choice of zone of city more subjected to railway noise; -one year of campaigns of measurements of acoustic levels in cout points through cin accordance with rules EN 60651/1995 and EN 61260/1995 and in conformity with previously referred Legislative Decrees; -drafting of “measurement reports”; -acoustical computer simulations in investigated areas by 3D MITHRA software by previous orographycal and metheoclimate characterizations of areas; -validation of acoustical simulation by direct comparison between measured data with that ones resulting by simulation; -elaboration of acoustical maps of area and both singling out and location of critical zone for exposure by railway noise. The paper wants to show, moreover, some technical of noise mitigation feasible in investigated system to take back the values of critical noise levels to that ones allowed by regulations and some interesting features too about railway noise that can suggest a new method to investigate about railway noise with easier times of measurements in field by use of MITHRA code.