Map Viewing Service (WMS) of the dataset: Noise zones (Type C map, LD index) of the A57, national road network granted

European Directive 2002/49/EC of 25 June 2002 on the assessment and management of environmental noise entails for EU Member States an assessment of environmental noise in the vicinity of major transport infrastructure (land and air) and in large agglomerations. This assessment is carried out in particular through the development of ‘so-called’ noise maps, the first series of which were drawn up in 2007 (1st deadline of the Directive) and 2012 (2nd deadline). Article L572-5 of the Environmental Code states that these maps are “reviewed, and if necessary revised, at least every five years”. Thus, the implementation of this review leads, in 2017 and as appropriate, to revise or renew the maps previously developed. Strategic Noise Maps (CBS) are designed to allow for the overall assessment of exposure to noise and to forecast its evolution. CBS are required in particular for road infrastructure with annual traffic of more than 3 million vehicles per year. For major road and rail transport infrastructure, the CBS are established, decided and approved under the authority of the prefect of the department. Noise maps are developed according to the indicators established by the European Directive, namely Lden (Day Evening Night Level) and Ln (Night Level). • Day/day: [6h-18h] • Evening/evening: [18h-22h] • Night/night: [22h-6h] The Lden and Ln indicators correspond to a defined energy average over the periods (Day/Black/Night) for Lden and (Night) for Ln. The corresponding results are expressed in A or dB(A) weighted decibels. Type C maps represent areas where noise limit values are exceeded for residential, educational and health buildings. For road and high-speed railway lines, the limit values are 68 dB(A) in Lden and 62 dB(A) in Ln.2002年6月25日发布的欧盟《关于环境噪声评估与管理的2002/49/EC号指令》，要求欧盟成员国对主要交通基础设施（陆路与航空）周边及大型聚居区开展环境噪声评估。 该项评估主要通过绘制"所谓"噪声地图开展，首批噪声地图分别于2007年（指令首个截止期限）与2012年（第二个截止期限）编制完成。 《法国环境法典》第L572-5条规定，此类噪声地图"至少每五年复核一次，必要时予以修订"。 因此，该项复核工作于2017年启动，视情况对此前编制的噪声地图进行修订或更新。 战略噪声地图（Strategic Noise Maps，CBS）旨在实现噪声暴露的整体评估，并对噪声变化趋势进行预测。 针对年车流量超过300万辆的道路基础设施，需编制此类战略噪声地图。 对于主要公路与铁路交通基础设施，战略噪声地图由所在省省长负责编制、审定与批准。 噪声地图需依据欧盟指令规定的指标编制，即Lden（Day Evening Night Level，昼间夜间综合声级）与Ln（Night Level，夜间声级）。其中： • 昼间时段：[6时至18时] • 晚间时段：[18时至22时] • 夜间时段：[22时至次日6时] Lden与Ln指标分别对应昼间、晚间、夜间时段内的能量平均声级，计算结果以A计权分贝（dB(A)）或A声级表示。 C类噪声地图（Type C maps）指住宅、教育与医疗建筑所在区域噪声限值超标的区域。 针对公路与高速铁路线路，其噪声限值标准为：Lden限值68 dB(A)，Ln限值62 dB(A)。