# 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 principles

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

For road surfaces with acoustic properties different from those of the reference surface, a spectral correction term for both rolling noise and propulsion noise shall be applied.
The road surface correction term for the rolling noise emission is given by:
ΔL WR,road,i,m = α i,m + β m × lg v m v ref
(2.2.19)
where
αi,m is the spectral correction in dB at reference speed vref for category m (1, 2 or 3) and spectral band i.
βm is the speed effect on the rolling noise reduction for category m (1, 2 or 3) and is identical for all frequency bands.
The road surface correction term for the propulsion noise emission is given by:
ΔLWP,road,i,m = min{αi,m ;0}
(2.2.20)
Absorbing surfaces decrease the propulsion noise, while non-absorbing surfaces do not increase it.

---
Source: https://www.legislation.gov.uk/eudr/2015/996/annex/division/ASSESSMENT/division/2/division/2.2/division/2.2.6/division/1 (the official version)
Page: https://openlegislation.uk/eu-directive-2015-996/annex/division-ASSESSMENT/division-2/division-2.2/division-2.2.6/division-1
Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives.