Lnight noise level of main roads in Wallonia - 2017 report

This polygonal data layer locates noise exposure exclusively from main roads (3 to 6 million vehicles per year) outside agglomerations according to the Lnight index and integrated into the 2017 European report. The Lnight index is one of the two indicators recommended by the European Directive 2002/49/EC, relating to the assessment and management of environmental noise, in order to measure the noise level describing environmental noise. Within the meaning of the Directive, the latter is emitted by means of transport, road, rail or air traffic or comes from sites of industrial activity. The Lnight (or Ln – Level Night) index represents the average noise level determined over all night periods (from 11 p.m. to 7 a.m.) in a year. This index is, by definition, an exclusive noise index for the night period. It is associated with sleep disturbances. It is expressed in decibel A (dB(A)), which is the unit chosen to represent the sensitivities of the human ear. The lower noise level limit to be reported for the Lnight index is 50 dB. According to the criteria defined for the mapping of noise emanating from the main roads, the data layer covers only those regional road sections for which road traffic is between 3 and 6 million vehicles per year. Sections with road traffic in excess of 6 million vehicles were pre-mapped (2006). The data layer is a polygonal vector layer with, as an attribute, the value Lnight. 5 exposure classes are mapped: 50-54, 55-59, 60-64, 65-69 and > 70 dB(A). The low and high values of the exposure class concerned shall be recalled as an attribute. The indicator is averaged over a calendar year. The data layer is therefore representative of a regional annual situation. The mapping of the main roads (3 to 6 million vehicles/year) was drawn up on the basis of source data dating from 2014 or collected at the beginning of 2015. Therefore, the data layers transcribe noise exposure to this period of time. The information was reported to the European Environment Agency in 2017 and therefore included in the 2017 report.