SIST-TS CEN/TS 18194:2026

SLOVENSKI STANDARD
01-februar-2026
Značilnosti cestnih in vzletnih površin - Karakterizacija akustičnih lastnosti
cestnih površin
Road and airfield surface characteristics - Characterisation of the acoustic properties of
road surfaces
Oberflächeneigenschaften von Straßen und Flugplätzen - Charakterisierung der
akustischen Eigenschaften der Fahrbahnoberfläche
Caractéristiques de surface des routes et des aérodromes — Caractérisation acoustique
de chaussées
Ta slovenski standard je istoveten z: CEN/TS 18194:2025
ICS:
93.080.20 Materiali za gradnjo cest Road construction materials
93.120 Gradnja letališč Construction of airports
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

CEN/TS 18194
TECHNICAL SPECIFICATION
SPÉCIFICATION TECHNIQUE
December 2025
TECHNISCHE SPEZIFIKATION
ICS 93.080.20; 93.120
English Version
Road and airfield surface characteristics - Characterisation
of the acoustic properties of road surfaces
Caractéristiques de surface des routes et des Oberflächeneigenschaften von Straßen und
aérodromes - Caractérisation acoustique des Flugplätzen - Charakterisierung der akustischen
revêtements de chaussée Eigenschaften der Fahrbahnoberfläche
This Technical Specification (CEN/TS) was approved by CEN on 12 October 2025 for provisional application.

The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to
submit their comments, particularly on the question whether the CEN/TS can be converted into a European Standard.

CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS
available promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in
parallel to the CEN/TS) until the final decision about the possible conversion of the CEN/TS into an EN is reached.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2025 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 18194:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 4
Introduction . 5
1 Scope . 6
2 Normative references . 6
3 Terms and definitions . 7
3.1 Noise sources and noise measurement method . 7
3.2 Acoustic quantities and symbols . 7
3.3 Road related definitions . 8
3.4 Reference variables and parameters . 9
4 Symbols and abbreviations . 9
5 Basic principles of the procedure for characterization of noise properties of road
surfaces . 11
5.1 Test method to be used for characterization procedure . 11
5.2 Test vehicle . 11
5.3 Road speed categories and associated reference speeds . 11
5.4 Reporting acoustic performance . 12
5.5 Guideline for the practical use of RSNL levels . 12
6 Procedure for characterizing the acoustic properties of a road surface type (acoustic
labelling) . 13
6.1 General . 13
6.2 Description of road surface type . 13
6.3 Selection of test sections and sampling principles . 13
6.3.1 Selection of test sections . 13
6.3.2 Minimum number of test sections for noise labelling . 13
6.3.3 Age of test sections . 13
6.3.4 Length of test sections and homogeneity requirement . 13
6.3.5 Number of repetitions . 13
6.4 Test tyres . 14
6.5 Reference speeds . 14
6.6 Results . 14
7 Procedure for the in situ conformity-of-production (COP) acoustic assessment of a
newly laid road surface . 14
7.1 General . 14
7.2 Description of road surface type . 14
7.3 Selection of road section and sampling principles . 15
7.3.1 Selection of road section . 15
7.3.2 Age of road section . 15
7.3.3 Length of road section . 15
7.3.4 Number of repetitions . 15
7.3.5 Reference speed . 15
7.4 Test tyres . 15
7.5 Results . 15
8 Procedure for monitoring the acoustic properties of road sections . 16
8.1 General . 16
8.2 Description of road surface type . 16
8.3 Selection of road section and sampling principles . 16
8.3.1 Selection of test sections . 16
8.3.2 Age of road section and frequency of acoustic monitoring . 16
8.3.3 Number of repetitions . 17
8.3.4 Reference speed . 17
8.4 Test tyres. 17
8.5 Output results . 17
8.5.1 General . 17
8.5.2 Comparisons with previous results . 17
9 Procedure for the determination of the road correction terms ΔL for use in the
WR,road
CNOSSOS-EU noise mapping . 17
9.1 General . 17
9.2 Frequency range of the measurements . 18
9.3 Reference conditions. 18
9.3.1 Reference CPX noise levels . 18
9.3.2 Generic speed coefficients . 19
9.4 Direct determination of the road surface corrections ΔL on a road network . 19
WR,road
9.4.1 Measuring procedure . 19
9.4.2 Test tyre . 20
9.4.3 Reference speed . 20
9.4.4 Measurement results . 20
9.4.5 Calculation of road surface correction . 20
9.5 The collection of spectral input data α and β . 22
i,m m
9.5.1 Measuring procedure . 22
9.5.2 Age of test sections. 22
9.5.3 Test tyre . 22
9.5.4 Reference speed . 22
9.5.5 Measurement results . 22
9.5.6 Determination of spectral coefficients α . 23
i,m
9.5.7 Determination of speed coefficient β . 23
m
10 Uncertainty assessment according to ISO/IEC Guide 98-3 . 24
11 Test report . 25
Annex A (informative) Proposed standard notation for road surface types . 27
Annex B (normative) Basic information on CNOSSOS-EU road traffic noise model . 31
Annex C (normative) Reference data. 33
C.1 General . 33
C.2 For tyre P1 . 34
C.3 For tyre H1 . 35
Annex D (normative) Sources of uncertainty . 36
D.1 General . 36
D.2 Uncertainty in the CPX method . 36
D.3 Variance in the test specimen . 36
D.4 Variance in the relation between CPX and sound emission of road vehicle . 37
D.5 Summary . 38
D.6 Data from ROSANNE report D2.6 [5] . 38
Bibliography . 39

European foreword
This document (CEN/TS 18194:2025) has been prepared by Technical Committee CEN/TC 227 “Road
materials”, the secretariat of which is held by BSI.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN/CENELEC Internal Regulations, the national standards organisations of the follow-
ing countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cy-
prus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United King-
dom.
Introduction
Road surface characteristics have a significant influence on the emission and propagation of road traffic
noise. The generation of tyre/road noise is dependent on pavement texture and pavement porosity. Ad-
ditionally, porosity leads to sound absorption properties of the pavement that also reduce the sound
propagation of the overall vehicle noise. In certain cases, also the elasticity of the pavement can play a
role. Pavement influence can lead to substantial differences in sound levels, associated with a given traffic
flow and composition, from different road surfaces.
In order to successfully use low-noise pavements as noise abatement measures it is essential to accu-
rately evaluate the acoustic performance of such pavements using a standardized procedure. Within the
European FP5 project SILVIA, a first proposal for such a common European noise characterization meth-
odology was proposed [1]. The project however ended before any validation of the characterization
methodology was performed and there has only been, at best, a very limited adoption of the principles of
the methodology. It was then felt necessary to reconsider the features in the SILVIA procedure, in partic-
ular the combined use of two measurement standards with the basic SPB (Statistical Pass-By) method [2]
and the CPX (Close-Proximity) method in order to increase the accuracy of the whole system and to facil-
itate its implementation.
Currently standardized measurement methods exist, such as those detailed in the ISO 11819 series (the
Statistical Pass-By (SPB) and the Close Proximity (CPX) method) [3]. In some countries, national road
surface characterization procedures exist and make use of one or both measurement methods; however,
the methods are not uniformly and consistently applied across Europe and there is little commonality in
the characterization procedures, which prevents a consistent comparison of products and performances.
Furthermore, there are many different national methods for calculating or predicting environmental
noise from road traffic that are linked to these acoustic pavement characterization procedures. With the
common noise calculation method required by the European Noise Directive 2002/49/EC and described
in the so-called “CNOSSOS-EU” Directive 2015/996/EC [4], it is possible to determine road surface effect
on environmental noise based on a consistent set of input parameters for any type of road surface. As
such, road surface performance is part of the input parameters of this common European environmental
noise calculation method (CNOSSOS-EU). Obviously, a common acoustic pavement characterization pro-
cedure could be used to enable road planners, road administrators, contractors, and manufacturers of
“low-noise” and other pavements to assess in a consistent way the acoustic performance of road pave-
ments.
Finally, a correct and uniform assessment of the acoustic properties of low noise pavements can help to
reduce trade barriers between the Member States and stimulate research and technical development in
this field.
1 Scope
This document describes an assessment procedure for characterizing the effect of different pavement
types on road traffic noise emission.
The procedure relies on the application of an established measurement method and specifies the detailed
conditions for its use to enable the determination of characteristic values for the acoustic performance of
road surface types with a given accuracy. Performance is characterized in absolute terms rather than with
respect to a reference surface, as specifications for the latter differ from country to country and could
contribute to additional uncertainty.
The procedure is intended to be suitable for the following applications:
— for the acoustic labelling (i.e. the determination of initial acoustic properties) of generic or proprie-
tary road surface products;
— for the conformity-of-production (COP) assessment of newly laid surfaces, e.g. to assess compliance
with acoustic labels and/or contract specifications, or to assess the homogeneity of the surface over
its length;
— for the monitoring of the acoustic properties of road surfaces over the course of their working life-
time, so as to help inform surface maintenance/replacement policies and increase understanding of
the acoustic durability of road surfaces.
The values derived from this procedure are intended to be used for the following purposes:
— to characterise the initial acoustic properties of a road surface type (the acoustic label) using a com-
mon procedure across Europe. Such an acoustic label can serve as a baseline for setting performance
requirements in public procurements, COP assessments and monitoring over the working lifetime of
the surface. The label enables the comparison of different road surface types in an unbiased manner;
— to verify the acoustic quality and homogeneity of a newly laid road surface;
— to determine the acoustic quality and homogeneity of a road surface at a given point during its work-
ing lifetime; the collation of sufficient data on the same surface over time enables the prediction of
acoustic behaviour and can help to drive surface design/development.
In addition, the procedure described within this document also makes possible:
— the establishment of reference values for wider road surface types;
— the derivation of input parameters for road surface corrections within environmental noise calcula-
tion methods (in particular, the harmonised CNOSSOS-EU method).
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indis-
pensable for its application. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies:
ISO 11819-2:2017, Acoustics — Measurement of the influence of road surfaces on traffic noise — Part 2:
The close-proximity method
ISO/TS 11819-3, Acoustics — Measurement of the influence of road surfaces on traffic noise — Part 3: Ref-
erence tyres
3 Terms and definitions
For the purposes of this part of this document, the following terms and definitions apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— IEC Electropedia: available at https://www.electropedia.org/
— ISO Online browsing platform: available at https://www.iso.org/obp
3.1 Noise sources and noise measurement method
3.1.1
traffic noise
overall noise emitted by the road traffic
3.1.2
vehicle noise
total noise emitted by an individual vehicle
Note 1 to entry: The two major components are tyre/road noise and power unit noise, but aerodynamic noise can
play a role as well (e.g. for heavy vehicles).
3.1.3
tyre/road noise
noise generated by the tyre/road interaction
3.1.4
power unit noise
noise generated by the vehicle engine, exhaust system, air intake, fans, transmission, etc.
3.1.5
close-proximity (CPX) method
measurement method as defined in ISO 11819-2
3.2 Acoustic quantities and symbols
3.2.1
CPX level, L
CPX
time-averaged A-weighted sound pressure level of the tyre/road noise as determined by the CPX method
defined in ISO 11819-2
Note 1 to entry: This can be either a broadband level or spectral levels, as required.
Note 2 to entry: The CPX level is expressed in decibels. In order to provide more information, additional suffixes are
used; see Table 1.
3.2.2
road surface noise label, RSNL
cat
label given to a certain road surface for a specific road category, where 'cat' denotes the road speed cate-
gory (defined as 'High', 'Medium' or 'Low')
Note 1 to entry: A surface can have RSNL values for multiple road speed categories, each value being determined
from measurements at the appropriate reference speed. These values are not transferrable from one category to
another.
3.2.3
standard deviation related to the measurement uncertainty, 𝝈𝝈
𝒎𝒎
standard deviation related to the measurement uncertainty in the context of CPX measurements
3.2.4
standard deviation of the product, 𝝈𝝈
𝒑𝒑
standard deviation related to the product variation, based on labelling results and used e.g. in the context
of conformity of production test (COP)
3.2.5
acoustic variability, s
t
acoustic variability due to road surface inhomogeneities, as defined in ISO 11819-2
Note 1 to entry: It corresponds to the standard deviation of the A-weighted sound pressure levels over all segments,
when using reference tyre t.
3.3 Road related definitions
3.3.1
road surface
durable surface material laid down as the top layer of a road structure in contact with the vehicular traffic
3.3.2
road surface type
specific combination of mix-design and laying procedure that leads to road surface with similar physical
and mechanical properties, e.g. SMA 11
Note 1 to entry: This includes in particular specific maximum aggregate size, void content and layer thickness. Alt-
hough basic acoustic behaviour is rather similar within a type, there are certain differences in detailed noise prop-
erties depending on age and manufacturing. See also Annex A.
3.3.3
road section
total stretch of the road lane subject to testing
3.3.4
road segment
part of a road section, being 20 m long and intended for normalization of sound pressure levels from the
actual speed on that segment to a certain reference speed
3.3.5
road speed categories
type of roads defined with respect to the range of speeds at which the traffic flows
Note 1 to entry: Three categories are defined, usually associated with certain areas (urban, suburban, rural, etc.).
Each road speed category has an associated reference speed (a preferred speed) at which CPX measurements are
undertaken. The categories and reference speeds are defined in 3.3.6 to 3.3.8.
3.3.6
“low” road speed category
conditions which relate to traffic operating at an average speed less than 65 km/h
Note 1 to entry: These conditions are usually associated with urban traffic.
3.3.7
“medium” road speed category
conditions which relate to traffic operating at an average speed of 65 km/h to 109 km/h
3.3.8
“high” road speed category
conditions which relate to traffic operating at an average speed of 110 km/h or more
Note 1 to entry: These conditions are usually associated with motorway traffic in rural or suburban areas. It can
happen that heavy vehicles operate at lower average speeds due to speed restrictions.
3.4 Reference variables and parameters
3.4.1
reference speed, v
ref
speed value at which the noise levels are expressed
Note 1 to entry: The reference speed is expressed in kilometres per hour. Depending upon the road speed category,
the reference speed is 50 km/h, 80 km/h or 110 km/h.
3.4.2
reference tyres
tyres specified for the purpose of representing certain features related to tyre/road sound emission and
which have specified and reproducible standard properties
Note 1 to entry: The method described in this document comprises the use of two reference tyres: one representing
passenger tyres denoted by P, and one representing heavy vehicle tyres denoted by H.
Note 2 to entry: The reference tyres are specified in ISO/TS 11819-3.
4 Symbols and abbreviations
For the purposes of this part of this document, the following symbols and abbreviations apply.
Table 1 — Symbols and abbreviated terms used in this document and their value or unit
Symbol Value/unit Explanation
RSNL dB Road Surface Noise Label for each road speed category indi-
cat
cated by the subscript “cat“
W - Coefficient between 0 and 1 representing the noise effect of
P,cat
the passenger cars in the traffic mix for each road speed cat-
egory
W - Coefficient between 0 and 1 representing the noise effect of
H,cat
the heavy vehicles in the traffic mix for each road speed cat-
egory
L dB Measure of the acoustic properties of the tested road sec-
CPX:P,v
ref
tion, for tyre(s) representing light vehicles, at the reference
speed, v
ref
L dB Measure of the acoustic properties of the tested road sec-
CPX:H,v
ref
tion, for tyre(s) representing heavy vehicles, at the reference
speed, v
ref
Symbol Value/unit Explanation
dB Standard deviation related to the measurement uncertainty
σ
m
dB Standard deviation related to the product variation
σ
p
T P or H Tyre type defined for testing passenger car tyres (P) and
heavy vehicle tyres (H)
s dB Acoustic variability due to surface inhomogeneities
t
v km/h Reference speed for CPX measurement, which varies de-
ref
pending on the road speed category
dB Road surface correction term for the calculation of sound
∆L
WR,road
power emission of vehicles
dB Road surface correction term for the calculation of sound
∆L
WR,road,i,m
th
power emission of vehicles in the i octave band and for the
category of vehicle m
i – Index of octave band ranging from 63 Hz (i = 1) to 8 kHz
(i = 8)
m 1, 2 or 3 Index representing the category of vehicles in the European
Noise Directive 2002/49/EC (m = 1 for passenger cars,
m = 2 for medium heavy vehicles and m = 3 for heavy vehi-
cles)
L dB CPX noise level for test tyre P at speed v in octave band i
CPX:P,i,v
L dB CPX noise level for test tyre H at speed v in octave band i
CPX:H,i,v
L (ref) dB Reference CPX noise level for test tyre P at 80 km/h in oc-
CPX:P,i,80
tave band i
L (ref) dB Reference CPX noise level for test tyre H at 80 km/h in oc-
CPX:H,i,80
tave band i
B – Speed coefficient on the reference road surface
ref
v km/h Maximum legal speed for the vehicle category m
m
α dB Spectral correction for the calculation of sound power emis-
i,m
sion of vehicles at the reference speed v = 70 km/h for ve-
ref
hicle category m and octave band i
β - Speed effect on the rolling noise for the calculation of sound
m
power emission of vehicles from category m
V 70 km/h Reference speed in [4]
refCNOSSOS-EU
dB CPX noise level in octave band i, measured with tyre P at the
L ,
CPX:P,i,vrefCNOSSOSEU
speed v = 70 km/h
refCNOSSOS-EU
dB CPX noise level in octave band i, measured with tyre H at the
L ,
CPX:H,i,vrefCNOSSOSEU
speed v = 70 km/h
refCNOSSOS-EU
Symbol Value/unit Explanation
b – Slope of the regression of the CPX levels measured at differ-
P
ent speeds with tyre P
b – Slope of the regression of the CPX levels measured at differ-
H
ent speeds with tyre H
dB Combined standard uncertainty
u (α )
c – Sensitivity coefficient to the error source k
k
Estimated standard uncertainty to the error source k
u(x ) dB
k
5 Basic principles of the procedure for characterization of noise properties of
road surfaces
5.1 Test method to be used for characterization procedure
The test method is based solely on the close proximity (CPX) method as defined in ISO 11819-2.
5.2 Test vehicle
The design and calibration of the test vehicle should satisfy the requirements set out in ISO 11819-2.
5.3 Road speed categories and associated reference speeds
Three categories of roads are defined with respect to the range of speeds at which the traffic flows; these
are usually associated with the road type (e.g. motorways, rural highways) and/or areas through which
the road passes (e.g. urban, suburban, rural, etc.). Each road speed category has an associated reference
speed at which the CPX measurements shall be undertaken. The reference speeds for the three categories
are defined as follows:
— 'low' road speed category: the corresponding reference speed is 50 km/h;
— 'medium' road speed category: the corresponding reference speed is 80 km/h;
— 'high' road speed category: the corresponding reference speed is 110 km/h.
It is recognized that when testing on some roads, use of the appropriate reference speeds as defined
above can be unachievable for either safety reasons and/or legislative reasons related to the testing ve-
hicle (e.g. the reference speed exceeds the permitted speed for un-braked trailers). In such instances, the
testing organization shall liaise in advance with the client and the responsible road authority to deter-
mine whether dispensation can be agreed to allow testing at the required reference speed or whether
measurements should be performed at a lower (target) speed and the measured levels adjusted to give
noise levels at the required reference speed. Any deviation from the required reference speed shall be
fully justified within the test report.
For 'low' road speed category measurements, if the reference speed is unachievable, the lowest permis-
sible target speed shall be 30 km/h.
For 'high' road speed category measurements, if the reference speed is unachievable, the lowest permis-
sible target speed shall be 80 km/h.
5.4 Reporting acoustic performance
The acoustic performance of the road surface for the required shall be reported in terms of the CPX
level(s) for car tyres L and, if measured, the level for heavy vehicle tyres L .
CPX:P,v CPX:H,v
ref ref
If CPX levels are available for both reference tyres, the acoustic performance shall also be reported in
terms of the Road Surface Noise Label (RSNL) defined by Formula (1):
(1)
RSNL= W ×L +× W L
cat P,catCPX:P,v H,cat CPX:H,v
ref ref
where
RSNL is the Road Surface Noise Label for the road speed category indicated by the sub-
cat
script “cat“;
𝑊𝑊 is the coefficient representing the noise effect of the passenger cars in the traffic
P,cat
mix for each road speed category;
𝑊𝑊 is the coefficient representing the noise effect of the heavy vehicles in the
H,cat
traffic mix for each road speed category;
L measure of the acoustic properties of the tested road section, for tyre(s) represent-
CPX:P,v
ref
ing light vehicles, at the reference speed, v ;
ref
L Measure of the acoustic properties of the tested road section, for tyre(s) represent-
CPX:H,v
ref
ing heavy vehicles, at the reference speed, v .
ref
Note that for RSNL calculation, measurements with same reference speed v is to be used for both ref-
ref
erence tyres.
Further details on the calculation of and the corresponding weighting factors are given in 5.5.
It is mandatory to report absolute values L and - if measured - L . Optionally, one can
CPX:P,v CPX:H,v
ref ref
additionally express the result as a noise difference with respect to the virtual reference surface, as de-
fined in Annex L of ISO 11819-2:2017.
5.5 Guideline for the practical use of RSNL levels
The RSNL value should be calculated for all road speed categories where the road surface is expected to
be used. However, where multiple categories are applicable, the appropriate CPX levels shall be deter-
mined for each relevant reference speed according to Formula (1).
The coefficient representing the noise effect of passenger cars and heavy vehicles in the traffic mix for a
given road speed category are defined in Table 2. The RSNL is equivalent to the CPX sound index as de-
fined in ISO 11819-2 in the case of a Medium Road speed category.
Table 2— Coefficients for traffic mix composition to be used for calculation of the RSNL values
for each road speed category for both reference tyres
Road speed cate- Reference W W
P,cat H,cat
gory speed (km/h)
Low 50 0,60 0,40
Medium 80 0,50 0,50
High 110 0,40 0,60
6 Procedure for characterizing the acoustic properties of a road surface type
(acoustic labelling)
6.1 General
Characterization of the initial acoustic properties of a road surface type is also referred to as 'acoustic
labelling'.
The acoustic label should preferably be applied to 'new' surfaces (see 6.3.2) where there is no evidence
of ageing effects. It shall be determined for all road speed categories where it is expected to be used.
The minimum number of test sections required as well as the minimum number of repetitions are based
on the considerations outlined in Chapter 5.1 of Part I of [5].
6.2 Description of road surface type
The road surface under assessment shall be described in terms of the following material and physical
properties:
— road surface type (both generic type (see Annex A for guidance) and proprietary product name);
— rate of laying;
— surface treatment (if relevant);
— aggregate size;
— layer thickness;
— void content (accessible or non-accessible);
— open-graded/ dense/ absorbing;
— binder type.
6.3 Selection of test sections and sampling principles
6.3.1 Selection of test sections
The test sections shall be carefully selected through consultation involving measurement institution and
road manufacturers and shall be compliant with the site requirements set out in Clause 7 of
ISO 11819-2:2017. The different test sections should be laid using different day batches and by different
crews.
6.3.2 Minimum number of test sections for noise labelling
A minimum number of five test sections shall be tested to determine the acoustic label.
6.3.3 Age of test sections
The test sections shall be tested between 2 and 6 months after paving is completed and prior to exposure
to winter maintenance practices. The traffic volume on the test section shall be such that at least 50 000
vehicle passages have occurred in the test lane prior to testing.
6.3.4 Length of test sections and homogeneity requirement
The length of each test section shall be a minimum of 200 m without interruption of the road surface;
ideally the length shall be 500 m or longer.
6.3.5 Number of repetitions
CPX measurements shall be performed at least three times (meaning one measurement and two repeti-
tions) on each test section for each reference tyre and for each applicable reference speed.
6.4 Test tyres
The reference tyres P and H are specified in ISO/TS 11819-3.
CPX measurements shall be performed on each test section using all reference tyres that are relevant to
the intended use of the road surface type. If the road surface type under test is intended for use on roads
carrying both light and heavy traffic, (passenger cars and trucks) both reference tyres (tyre P and tyre H)
shall be used.
If the road surface under test is intended for use on roads carrying predominantly light traffic (passenger
cars only) then only tyre P is mandatory.
6.5 Reference speeds
Measurements shall be taken at least at one of the reference speeds of the CPX method (i.e. 50 km/h or
80 km/h) according to the road speed category where the surface is expected to be used, as specified in
3.3.5, unless dispensation is given to measure at different (lower) speeds (see Notes in 3.3.5 to 3.3.8).
6.6 Results
For each reference speed used, L (and L if measured) shall be determined as the
CPX:P,v CPX:H,v
ref ref
arithmetic average of all the repetitions (at least 3) of the measured sections (at least five). These average
value(s) as well as the corresponding one-third octave band spectra shall be reported as the appropriate
road speed category acoustic labels for the road surface under assessment.
From all measured test sections, the product variation σ shall be computed as the standard deviation of
p
the levels (averaged on all the repetitions) on all the test sections.
Where measurements have been taken using both reference tyres, reporting of the Road Surface Noise
Label (RSNL) is optional. 5.4 and 5.5 include information on how this shall be calculated.
7 Procedure for the in situ conformity-of-production (COP) acoustic assessment
of a newly laid road surface
7.1 General
Conformity-of-production (COP) measurements using the following procedure are intended to assess
compliance of a newly laid road surface with its acoustic label(s) or can be used to assess compliance
with individual contract specifications and to set up as a benchmark for possible routine acoustic moni-
toring.
The minimum number of repetitions proposed is based on the considerations outlined in Chapter 5.2 of
Part I of [5].
7.2 Description of road surface type
The road section under assessment shall be described in terms of the following material and physical
properties together with other relevant data as follows:
— road surface type (both generic type (see Annex A for guidance) and proprietary product name);
— date of laying;
— surface treatment (if relevant);
— aggregate size;
— layer thickness;
— void content (accessible or non-accessible);
— open-graded/ dense/ absorbing;
— binder type;
— declared acoustic label for the road surface type, L and, if applicable, L including
CPX:P,v CPX:H,v
ref ref
the product variations 𝜎𝜎𝜎𝜎 for both tyres.
7.3 Selection of road section and sampling principles
7.3.1 Selection of road section
The loca
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