The LIFE DYNAMAP project: Towards a procedure for dynamic noise mapping in urban areas

Noise maps are considered a powerful tool for determining the population exposure to environmental noise. To make the process of updating noise maps easier, more cost effective and more frequent, there is a need for integrated systems that combine real-time measurement and processing to assess the acoustic impact of noise sources. To this end, a dedicated project, named Dynamic Acoustic Mapping (DYNAMAP), has been proposed and co-financed in the framework of the Financial Instrument for the Environment (LIFE) 2013 program with the aim of developing a dynamic noise mapping system capable of detecting and representing in real-time the acoustic impact of road infrastructures. Noise maps are updated by scaling the noise levels of pre-calculated noise maps as functions of the differences observed between measured and calculated original grid data. The total map is updated by energetic summation of single source levels from updated noise maps. Given the large number of roads present in Milan city, obtaining the dynamics acoustics map of this city requires application of a statistical approach where the roads having similar flow conditions-and thus similar noise trends-are grouped (clustered) together. In order to obtain these groups (clusters), an extensive measurement campaign was executed. The maps obtained using this method can be associated with an error that will depend on the chosen integration time of noise levels. Results show that two statistical clusters differentiated by rush hour traffic flow are sufficient and better for categorization than the road types provided by Italian road regulation.