# Commission Directive (EU) 2015/996 of 19 May 2015 establishing common noise assessment methods according to Directive 2002/49/EC of the European Parliament and of the Council (Text with EEA relevance), Division: General equation

Extent: E+W+S+N.I.

The rolling noise sound power level in the frequency band i for a vehicle of class m = 1,2 or 3 is defined as:
L WR,i,m = A R,i,m + B R,i,m × lg v m v ref + ΔL WR,i,m
(2.2.4)
The coefficients AR,i,m and BR,i,m are given in octave bands for each vehicle category and for a reference speed vref = 70 km/h. ΔLWR,i,m corresponds to the sum of the correction coefficients to be applied to the rolling noise emission for specific road or vehicle conditions deviating from the reference conditions:
ΔLWR,i,m = ΔLWR,road,i,m + ΔLstuddedtyres,i,m + ΔLWR,acc,i,m + ΔLW,temp
(2.2.5)
ΔLWR,road,i,m accounts for the effect on rolling noise of a road surface with acoustic properties different from those of the virtual reference surface as defined in Chapter 2.2.2. It includes both the effect on propagation and on generation.
ΔLstudded tyres,i,m is a correction coefficient accounting for the higher rolling noise of light vehicles equipped with studded tyres.
ΔLWR,acc,i,m accounts for the effect on rolling noise of a crossing with traffic lights or a roundabout. It integrates the effect on noise of the speed variation.
ΔLW,temp is a correction term for an average temperature τ different from the reference temperature τref = 20 °C.

---
Source: https://www.legislation.gov.uk/eudr/2015/996/annex/division/ASSESSMENT/division/2/division/2.2/division/2.2.3/division/1 (the official version)
Page: https://openlegislation.uk/eu-directive-2015-996/annex/division-ASSESSMENT/division-2/division-2.2/division-2.2.3/division-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.