A new approach to road traffic noise assessment in Milan

In the last years the Municipality of Milan has promoted some important policies in order to obtain an in-depth knowledge of road traffic noise. The city government has paid particular attention to cost containment, especially concerning the monitoring activities. One of the main features of the noise source under investigation, i.e. road traffic, is the repetitiveness of the trend of 24 hour time series of hourly LAeq. Thanks to this feature and on the basis of roads classification it is possible to obtain the noise levels generated from the almost all urban roads by means of a limited number of measurement points. For this purpose we used the methodology called “stratified spatial sampling”. Since the aim is to get the noise levels generated by road traffic it is necessary to identify and remove unwanted sound events from measurements. The Disat-UNIMIB and IDASC- CNR are developing an automatic procedure to identify and remove unwanted sound events from measurements by using the results of permanent monitoring terminals. In the future we expect to achieve a monitoring network/noise simulation model integrated system that allows to update in real time the city noise map for road source from data provided by the monitoring terminals.