4. Measurement methods and environmental indicators for road noise

The overall assessment of road noise by measurement is described in standard NF S 31085. It consists of placing a microphone 2 m from the façade of a dwelling and measuring the noise received over a period of at least 24 hours. The measurements are accompanied by a traffic count in order to compare situations of equal noise emission. The final indicator will therefore be an A-weighted equivalent energy level, L _Aeq [T], over a reference period T (e.g. 6 h – 22 h during the day, 22 h – 6 h at night). This measurement can be used, for example, to check compliance with noise legislation. The measured indicator is also consistent with the L _den and L _n indicators used in Directive 2002/49/EC, since L _n corresponds...