# Optimized Sensors Network and Dynamical Maps for Monitoring Traffic Noise in a Large Urban Zone  
[PERSON]  
1 Dipartimento di Scienze dell'Ambiente e del Territorio e di Scienze della Terra (DISAT),  
Universita di Milano-Bicocca, Piazza della Scienza 1, 20126 Milano, Italy; [EMAIL_ADDRESS]  
[PERSON]  
2 Dipartimento di Fisica, Universita di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano, Italy,  
[EMAIL_ADDRESS]  
[PERSON]  
1 Dipartimento di Scienze dell'Ambiente e del Territorio e di Scienze della Terra (DISAT),  
Universita di Milano-Bicocca, Piazza della Scienza 1, 20126 Milano, Italy; [EMAIL_ADDRESS]  
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with Action Plans, provide a framework to manage environmental noise and its effects. Thus, they represent the standard approach for noise prevention and control. The deployment of distributed acoustic monitoring stations in urban and suburban areas started about a decade ago, in concomitance with the lowering costs of electronic components and the availability of efficient hardware for data transfer. Such extended monitoring technique has continuously grown in popularity since the publication of the END by the recognition that acoustic maps represent a powerful tool for determining the exposure of population to environmental noise. Until recently, noise maps were normally obtained by using mean vehicle flows, averaged over a period of one year, but this simple approach clearly lacks accuracy when dealing with varying noise on a daily basis. As a result, noise maps had been evolving towards a multi-source predictive approach [4; 5; 6; 7; 8]. It then became clear that instead 'dynamical' (i.e., time dependent) noise maps should be developed for obtaining realistic and accurate noise predictions over shorter time scales. In other words, the introduction of dynamic noise maps constitutes a further evolution in the direction of better representing the actual noise exposure. The Dynamap project, dubbed 'Dynamic Acoustic Mapping: Development of low cost sensors networks for real-time noise mapping' [9; 10; 11; 12], is a LIFE project (ref. LIFE13 ENV/IT/001254), aimed at developing a dynamic noise mapping system, enabling to detect and represent the acoustic impact of road infrastructures in real time. Since the update of noise maps using a standard approach requires the collection and processing of a huge amount of data, such a procedure would be very time consuming and costly, having a significant impact on the financial statements of the authorities responsible for providing noise maps. Therefore, more elaborated solutions are required in order to reduce the cost of noise mapping activities. To meet such requirements, and the growing demand of information about noise pollution, the Dynamap project foresees the development of an automated noise mapping system delivering real-time (short-term) noise maps, as well as long-term noise assessments. Despite real-time noise maps not being explicitly required by END (see Appendix A), their automated generation is estimated to lower the cost of noise mapping conspicuously (see DYNAMP--Development of low cost sensor networks for real time noise mapping, LIFE Projects 2013, Environment Policy, and Governace--July 2014: Publications [12]), with added significant benefits for noise managers and receivers. As a result, the Dynamap system is expected to lead to a significant reduction in the resources needed to update the noise maps (time, costs, and dedicated personnel), and to improve and facilitate the dissemination of information to the public through appropriate web tools and/or the opportunity to abate noise with alternative measures based on traffic control and management.