Division: General equation - 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)

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} \times \lg (\frac{v_{m}}{v_{ref}}) + {ΔL}_{WR,i,m}

(2.2.4)

The coefficients A_R,i,m and B_R,i,m are given in octave bands for each vehicle category and for a reference speed v_ref = 70 km/h. ΔL_WR,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:

ΔL_WR,i,m = ΔL_WR,road,i,m + ΔL_{studdedtyres,i,m} + ΔL_WR,acc,i,m + ΔL_W,temp

(2.2.5)

ΔL_WR,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.

ΔL_{studded tyres,i,m} is a correction coefficient accounting for the higher rolling noise of light vehicles equipped with studded tyres.

ΔL_WR,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.

ΔL_W,temp is a correction term for an average temperature τ different from the reference temperature τ_ref = 20 °C.

Division General equation