Table describing the Noise Zones of the major land transport infrastructure of the Gard department (Type C LD day)

Noise level zones describe a noise exposure situation based on a noise indicator or area affected by noise. They are used primarily for the preparation of strategic noise maps pursuant to Article R.572-5 of the Environmental Code. Noise zones are geometric elements of the strategic noise map. For type A maps (CBSTYPE), each noise zone is usually bounded by 2 isophone curves (Lden 55-60, 60-65, 65-70, 70-75 and Ln 50-55, 55-60, 60-65, 65-70) or shares the lower limit isophone curve (Lden >75, Ln > 70). The type B map locates the sectors affected by noise, defined by the noise classification of land transport infrastructure. For type C maps (CBSTYPE), each noise zone shall be bounded by the lower limit isophone curve (Lden > 68 or 73, Ln > 62 or 65).噪声级分区（Noise level zones）是依托噪声指标或受噪声影响区域，用以表征噪声暴露状况的单元，主要用于依据《环境法典》第R.572-5条编制战略噪声地图。 噪声分区是战略噪声地图的几何构成要素。 对于A型地图（CBSTYPE），每个噪声分区通常由两条等声级线（isophone）界定：涵盖昼夜等效声级（Lden）55~60、60~65、65~70、70~75，以及夜间等效声级（Ln）50~55、55~60、60~65、65~70；或以最低限值等声级线（Lden＞75、Ln＞70）作为边界。 B型地图用于划定受噪声影响的区域，其划分依据为陆路交通基础设施的噪声分级。 对于C型地图（CBSTYPE），每个噪声分区需以最低限值等声级线（Lden＞68或73、Ln＞62或65）作为边界。