Noise mapping in Rennes Métropole

Strategic Noise Maps (SNCs), pursuant to European Directive 2002/49/EC of 25 June 2002, are intended to enable the overall assessment of exposure to environmental noise and to provide general forecasts of its development. They include a set of graphic representations and numerical data. Rennes Métropole undertook the review of the CBS agreed in 2010 with a design office (Impédance). New CBS were produced in 2019 to meet the third deadline of the European directive, taking into account an enlarged territory of 43 municipalities. The CBS 2021 of Rennes Métropole, known as the fourth deadline, was approved by the Rennes Métropole Council on 18 November 2021. They constitute a new update to constitute the diagnosis of the new noise prevention plan (PPBE) of Rennes Métropole, and meet the fourth deadline of the directive. Attention should be drawn to the limitations of noise maps, which are an "approach" to reality. \- The CBS are intended to highlight situations of strong nuisances from a macroscopic approach. They are not a diagnosis on a fine scale. Areas subject to excessive noise will require further investigation. \- The reference date of the input data is out of date with the date of approval of the CBS: Demographic (2018), Topographic (2018), Traffic Entry Data (2014-2020). \- Data gaps for traffic on some municipal roads: choice not to apply the flat-rate values. \- Limits related to topographical data: anomalies have been noted in the destination of a few buildings which show business buildings as dwellings. Field investigations and feedback from municipalities have made it possible to make the geographical data layer "houses" more reliable. \- For the source "railway noise", the inclusion of SNCF Réseau 2012 data due to the lack of more recent data at the time of the preparation of the new CBS, and the non-inclusion of the new TGV line due to the lack of data available at the study stage. \- For the source "air noise", the CBS integrates the data of the noise exposure plan of Rennes-Saint-Jacques airport (prefectural order of 2010) established on departures and arrivals at the level of the platform, but not all the trajectories of aircraft flying over the territory. \- Overestimation of exposed populations: CBS calculation methods tend to increase actual noise levels. \- Noise maps are indicative of noise levels and are not opposable as such. Concerning the noise pollution of infrastructures, the noise classification of the tracks decided by the prefect for each transport infrastructure, as well as the noise exposure plan of the airport, constitute the main legal reference. These documents may lay down stricter rules on construction and, in particular, on acoustic insulation of facades. The information is available from the prefecture and municipalities (PLU intercommunal). The noise maps of Rennes Métropole were approved by the Community Council on 25 November 2021. They were updated on 13 April 2023 (noise barriers + rail noise). The LGV and the 2nd metro line were included in the study. This update also includes a Health Annex (Decree No 2021-1633 of 14 December 2021). [Detailed technical information](https://public.sig.rennesmetropole.fr/geonetwork/srv/fre/catalog.search#/metadata/c692e05f-70c9-4b5d-89b3-ef4e0f4b1129) [Click here to download (OGC GeoPackage - 95 MB)](https://public.sig.rennesmetropole.fr/resources/donnees/sec_sanit/noisit/2021/carto_noisit_2021.gpkg)