According to the definitions provided in Legislative Decree no. 194, of 19 August 2005, noise mapping is "the representation of data relating to an existing or predicted noise situation in an area relating to a specific source".
Noise maps are reviewed and revised every five years.
Autostrade per l'Italia updates and forwards the noise maps for the entire network under concession to the competent authorities. In particular, so as to allow strategic noise mapping, Autostrade per l'Italia transmitted the noise mapping update for urban agglomerations with more than 250,000 inhabitants and the first noise mapping for urban agglomerations with between 100,000 and 250,000 inhabitants to the Ministry of the Environment, the competent autonomous Regions/Provinces autonomous and the municipalities concerned by 31/12/2011.