SIST EN ISO 13473-5:2025

SLOVENSKI STANDARD
01-maj-2025
Nadomešča:
SIST EN ISO 13473-5:2010
Karakterizacija teksture vozišča z uporabo profilov površine - 5. del: Ugotavljanje
megateksture (ISO 13473-5:2025)
Characterization of pavement texture by use of surface profiles - Part 5: Determination of
megatexture (ISO 13473-5:2025)
Charakterisierung der Textur von Fahrbahnbelägen unter Verwendung von
Oberflächenprofilen - Teil 5: Bestimmung der Megatextur (ISO 13473-5:2025)
Caractérisation de la texture d'un revêtement de chaussée à partir de relevés de profils
de la surface - Partie 5: Détermination de la mégatexture (ISO 13473-5:2025)
Ta slovenski standard je istoveten z: EN ISO 13473-5:2025
ICS:
17.140.30 Emisija hrupa transportnih Noise emitted by means of
sredstev transport
93.080.20 Materiali za gradnjo cest Road construction materials
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

EN ISO 13473-5
EUROPEAN STANDARD
NORME EUROPÉENNE
March 2025
EUROPÄISCHE NORM
ICS 17.140.30; 93.080.20 Supersedes EN ISO 13473-5:2009
English Version
Characterization of pavement texture by use of surface
profiles - Part 5: Determination of megatexture (ISO
13473-5:2025)
Caractérisation de la texture d'un revêtement de Charakterisierung der Textur von Fahrbahnbelägen
chaussée à partir de relevés de profils de la surface - unter Verwendung von Oberflächenprofilen - Teil 5:
Partie 5: Détermination de la mégatexture (ISO 13473- Bestimmung der Megatextur (ISO 13473-5:2025)
5:2025)
This European Standard was approved by CEN on 13 March 2025.

CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.

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. EN ISO 13473-5:2025 E
worldwide for CEN national Members.

Contents Page
European foreword . 3

European foreword
This document (EN ISO 13473-5:2025) has been prepared by Technical Committee ISO/TC 43
"Acoustics" in collaboration with Technical Committee CEN/TC 227 “Road materials” the secretariat of
which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by September 2025, and conflicting national standards
shall be withdrawn at the latest by September 2025.
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.
This document supersedes EN ISO 13473-5:2009.
Any feedback and questions on this document should be directed to the users’ national standards
body/national committee. A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the
following countries are bound to implement this European Standard: 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 the
United Kingdom.
Endorsement notice
The text of ISO 13473-5:2025 has been approved by CEN as EN ISO 13473-5:2025 without any
modification.
International
Standard
ISO 13473-5
Second edition
Characterization of pavement
2025-03
texture by use of surface profiles —
Part 5:
Determination of megatexture
Caractérisation de la texture d'un revêtement de chaussée à
partir de relevés de profils de la surface —
Partie 5: Détermination de la mégatexture
Reference number
ISO 13473-5:2025(en) © ISO 2025

ISO 13473-5:2025(en)
© ISO 2025
All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may
be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on
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Phone: +41 22 749 01 11
Email: copyright@iso.org
Website: www.iso.org
Published in Switzerland
ii
ISO 13473-5:2025(en)
Contents Page
Foreword .iv
Introduction .v
1 Scope . 1
2 Normative references . 1
3 Terms and definitions . 1
3.1 General terms .1
3.2 Ranges of texture .3
3.3 Megatexture measurement method .5
4 Measurement instruments . 6
4.1 Instruments in general .6
4.1.1 General .6
4.1.2 Performance check .7
4.1.3 Indication of invalid readings (drop-outs) .7
5 Test surface considerations . 7
5.1 General .7
5.2 Test lengths.7
6 Measurement method . 8
6.1 General .8
6.2 Sensitivity to vertical motion of the vehicle .8
6.3 Calibration .9
6.4 Measuring speed .9
6.5 Measurement of the texture profile .9
7 Data processing . 10
7.1 General .10
7.2 Preprocessing: drop-out rate and validity of measurements.10
7.3 Spike identification and reshaping the profile .11
7.4 Resampling to a certain spatial resolution .11
7.5 Filtering of the profile .11
7.6 Calculation of RMS . 12
Me
7.7 Averaging . 12
7.8 Longitudinal standard deviation . 12
7.9 Singularities . 12
8 Measurement uncertainty .13
9 Safety considerations during measurements . 14
10 Test report .15
Annex A (normative) Spike removal procedure . 17
Annex B (informative) Example of test report and graphical presentations .20
Annex C (informative) Measurement uncertainty.25
Annex D (informative) Megatexture digital filters .28
Annex E (informative) Megatexture reference program code .30
Annex F (informative) Procedure for sampling of measurement sections if the whole area of
interest cannot be measured .31
Annex G (normative) Profile conditioning before filtering .34
Annex H (informative) Guidelines for choosing a suitable calculation length .37
Bibliography .39

iii
ISO 13473-5:2025(en)
Foreword
ISO (the International Organization for Standardization) is a worldwide federation of national standards
bodies (ISO member bodies). The work of preparing International Standards is normally carried out through
ISO technical committees. Each member body interested in a subject for which a technical committee
has been established has the right to be represented on that committee. International organizations,
governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely
with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.
The procedures used to develop this document and those intended for its further maintenance are described
in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types
of ISO document should be noted. This document was drafted in accordance with the editorial rules of the
ISO/IEC Directives, Part 2 (see www.iso.org/directives).
ISO draws attention to the possibility that the implementation of this document may involve the use of (a)
patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent
rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a)
patent(s) which may be required to implement this document. However, implementers are cautioned that
this may not represent the latest information, which may be obtained from the patent database available at
www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.
Any trade name used in this document is information given for the convenience of users and does not
constitute an endorsement.
For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions
related to conformity assessment, as well as information about ISO's adherence to the World Trade
Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.
This document was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise.
This second edition cancels and replaces the first edition (ISO 13473-5:2009), which has been technically
revised.
The main changes are as follows:
— default measure RMS in mm instead of L in dB;
Me Me
— use the same pre-processing procedures as in ISO 13473-1 (drop-out and spikes);
— use digital filters to calculate megatexture, earlier done by spectral analysis;
— improvements of the uncertainty description of megatexture calculations;
— informative annex with reference program and reference calculations, available at the www.erpug.org
homepage.
A list of all parts in the ISO 13473 series can be found on the ISO website.
Any feedback or questions on this document should be directed to the user’s national standards body. A
complete listing of these bodies can be found at www.iso.org/members.html.

iv
ISO 13473-5:2025(en)
Introduction
Pavement surface texture largely influences factors such as noise emission caused by tyre/road interaction
(see Reference [1]), tyre/pavement friction (see Reference [2]), and comfort, as well as rolling resistance (see
Reference [3]) and wear of tyres. Reliable methods of measuring and characterizing texture are therefore
essential. Texture is subdivided into micro-, macro- and megatexture according to ISO 13473-2. A method
for measurement and calculation of a macrotexture indicator based on a profile measurement is specified
[4]
in ISO 13473-1 . A procedure for measuring macrotexture by the volumetric patch method is described
[5]
in EN 13036-1 . Currently, no reliable and practical method of measuring pavement microtexture in situ
is available. This document aims to provide means of measuring and calculating a megatexture indicator
useful for pavement surface characterization.
Megatexture is an important texture range lying between macrotexture and unevenness. This type of
texture has wavelengths of the same order of magnitude as a tyre/road interface and is often a result of
potholes or ‘washboarding’. Some common types of singularities, such as a single depressed (e.g. a pothole)
or protruding (e.g. caused by tree roots) spot on the pavement, will also show up in a texture profile spectrum
as megatexture. Although some pavements, such as paving stones, possess an intrinsic megatexture, it is
usually an unwanted characteristic resulting from defects in the surface. Megatexture is an undesirable
feature, the higher the value, the worse the road is perceived: megatexture is known to increase tyre/road
noise by inducing tyre vibrations. At the same time, these tyre vibrations cause energy dissipation in the
tyre. The rolling resistance increases and this leads to highly unwanted fuel consumption and CO emission
(see also 3.2).
v
International Standard ISO 13473-5:2025(en)
Characterization of pavement texture by use of surface
profiles —
Part 5:
Determination of megatexture
1 Scope
This document specifies a procedure for determining the magnitude of pavement surface megatexture by
measuring the surface profile and calculating a megatexture descriptor from this profile. The technique is
designed to give meaningful and accurate measurements and descriptions of pavement megatexture for
various purposes, such as for the prediction of the acoustic quality of the pavement or the assessment of the
rolling resistance.
Since there is an overlap between megatexture and the surrounding ranges, megatexture descriptors
unavoidably have a certain correlation with corresponding measures in those ranges. This document
[4]
specifies measurements and procedures which are in relevant parts compatible with those in ISO 13473-1 ,
[6] [7]
ISO 8608 and EN 13036-5 .
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes
requirements of this document. For dated references, only the edition cited applies. For undated references,
the latest edition of the referenced document (including any amendments) applies.
ISO 13473-2, Characterization of pavement texture by use of surface profiles — Part 2: Terminology and basic
requirements related to pavement texture profile analysis
ISO 13473-3, Characterization of pavement texture by use of surface profiles — Part 3: Specification and
classification of profilometers
ISO/PAS 13473-6, Characterization of pavement texture by use of surface profiles — Part 6: Verification of the
performance of laser profilometers used for pavement texture measurements
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 13473-2 and the following apply.
ISO and IEC maintain terminology databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https:// www .iso .org/ obp
— IEC Electropedia: available at https:// www .electropedia .org/
3.1 General terms
3.1.1
texture wavelength
λ
quantity describing the horizontal dimension of the irregularities of a texture profile (3.1.3)
Note 1 to entry: Texture wavelength is normally expressed in metres (m) or millimetres (mm).

ISO 13473-5:2025(en)
Note 2 to entry: Texture wavelength is a descriptor of the wavelength components of the profile and is related to
the concept of the Fourier Transform of a series regularly sampled measurement points along a spatial axis. Vertical
displacement (height) has an arbitrary reference.
3.1.2
pavement texture
texture
deviation of a pavement surface from a true planar surface, with a texture wavelength (3.1.1) less than 0,5 m
Note 1 to entry: It is divided into micro-, macro- and megatexture according to 3.2.
3.1.3
surface profile
texture profile
upper contour of a vertical cross-section through a pavement
Note 1 to entry: The surface profile (texture profile) is further indicated with its mathematical descriptor Z(X).
Note 2 to entry: A typical profile recording of a pavement surface is illustrated in Figure 1 (vertical scale exaggerated),
including the terms profile, distance, vertical displacement and wavelength. “Wavelength” in the figure is an illustration
of a component of the profile related to the wavelength concept but it is not correct from a strictly mathematical point
of view. Furthermore, the reference (bottom) line is arbitrary.
Note 3 to entry: The profile of the surface is described by two coordinates: one in the surface plane, called distance
(the abscissa), and the other in a direction normal to the surface plane, called vertical displacement (the ordinate). An
example is given in Figure 1. The distance may be in the longitudinal or lateral (transverse) directions in relation to
the travel direction on a pavement, or in a circle or any other direction between these extremes.
Note 4 to entry: Texture profile is similar to surface profile but limited to the texture range.
Key
X distance
Z vertical displacement
1 surface profile
2 texture wavelength
Figure 1 — Illustration of some basic terms describing pavement surface texture
3.1.4
drop-out
data in the measured texture profile indicated by the sensor as invalid
3.1.5
spike
unusually high and sharply defined peak in the measured texture profile, which is not part of the true
texture profile and is not indicated as invalid by the sensor
Note 1 to entry: See Annex A for a quantitative definition of a spike.

ISO 13473-5:2025(en)
3.1.6
profilometer
device used for measuring the profile of a pavement surface Z(X) to be used for calculation of certain
mathematically defined measures
Note 1 to entry: Current designs of profilometers used in pavement engineering include, but are not limited to, sensors
based on laser, light sectioning, needle tracer and ultrasonics technologies. The most common sensor type used in
profilometers is laser based. In most cases, the profile is recorded for subsequent analysis, in some cases it may be
used only in real-time calculations.
Note 2 to entry: Specifications for profilometers are dealt with in ISO 13473-3.
3.2 Ranges of texture
3.2.1
microtexture
pavement microtexture
deviation of a pavement surface from a true planar surface with the characteristic dimensions along the
surface of less than 0,5 mm, corresponding to texture wavelengths up to 0,5 mm expressed as one-third-
octave centre wavelengths
Note 1 to entry: Peak-to-peak amplitudes normally vary in the range 0,001 mm to 0,5 mm. This type of texture is the
texture which makes the surface feel more or less harsh but which is usually too small to be observed by the eye. It
is produced by the surface properties (sharpness and harshness) of the individual aggregate or other particles of the
surface which come in direct contact with the tyres.
Note 2 to entry: Based on physical relations between texture and friction, noise, etc., the World Road Association
(PIARC) has defined the ranges of micro-, macro- and megatexture earlier; see Reference [8]. Figure 2 illustrates
how these definitions cover certain ranges of surface texture wavelength and spatial frequency, and how various
characteristics are influenced within these ranges.

ISO 13473-5:2025(en)
Key
X1 wavelength
X2 spatial frequency [1/m]
1 unevenness
2 megatexture
3 macrotexture
4 microtexture
NOTE A lighter shade indicates a favourable effect over this range and a darker shade indicates an unfavourable effect.
Figure 2 — Ranges in terms of wavelength and spatial frequency of texture and unevenness and
[8]
their most significant, anticipated effects
3.2.2
macrotexture
pavement macrotexture
deviation of a pavement surface from a true planar surface with the characteristic dimensions along the
surface of 0,5 mm to 50 mm, corresponding to texture wavelengths with one-third-octave bands including
the range 0,63 mm to 50 mm of centre wavelengths
Note 1 to entry: Peak-to-peak amplitudes may normally vary in the range 0,1 mm to 20 mm. This type of texture is the
texture which has wavelengths of the same order of size as tyre tread elements in the tyre/road interface. Surfaces
are normally designed with a sufficient macrotexture to obtain a suitable water drainage in the tyre/road interface.
The macrotexture is obtained by suitable proportioning of the aggregate and mortar of the mix or by surface finishing
techniques. The size of the macrotexture has a positive correlation with the stone size of the pavement.

ISO 13473-5:2025(en)
3.2.3
megatexture
pavement megatexture
deviation of a pavement surface from a true planar surface with the characteristic dimensions along the
surface of 50 mm to 500 mm, corresponding to texture wavelengths with one-third-octave bands including
the range 63 mm to 500 mm of centre wavelengths
Note 1 to entry: Peak-to-peak amplitudes normally vary in the range 0,1 mm to 50 mm. This type of texture is
composed of wavelengths with the same order of size as a typical tyre/road interface and is often created by potholes
or ripples in the surface. It is usually an unwanted characteristic resulting from defects in the surface, but it can as
well be intrinsic to the pavement (e.g. cobble stones). Surface roughness with longer wavelengths than megatexture is
referred to as unevenness and typically takes the form of undulations in the surface.
3.2.4
unevenness
pavement unevenness
deviation of a pavement surface from a true planar surface with the characteristic dimensions along the
surface of 0,5 m to 50 m, corresponding to wavelengths with one-third-octave bands including the range
0,63 m to 50 m of centre wavelengths
Note 1 to entry: Pavement characteristics at wavelengths longer than 0,5 m are considered to be above that of texture
and are referred to here as “unevenness”. For airfield applications, even wavelengths longer than 50 m would be
considered.
Note 2 to entry: Longitudinal unevenness is a type of surface roughness which, through vibrations, affects ride comfort
in, and road holding of vehicles. Transverse unevenness, e.g. due to the presence of ruts, affects safety through lateral
instability and water accumulation. It is not the intention of this document to include terms which are specifically related
[6] [9] [10] [7]
to unevenness. Such terms are defined in ISO 8608 , ISO 16063-1 , ASTM E950/E950M-09 and EN 13036-5 .
3.3 Megatexture measurement method
3.3.1
measurement length
l
m
length of an uninterrupted texture profile which has been or is to be measured
Note 1 to entry: Measurement length is normally expressed in metres.
3.3.2
evaluation length
l
e
length of a portion of one or more profiles for which megatexture RMS (3.3.5) is to be evaluated
Me
Note 1 to entry: Evaluation length is normally expressed in metres.
Note 2 to entry: The evaluation length is always smaller or equal to the measurement length.
3.3.3
calculation length
l
c
length of a portion of one or more profiles for which megatexture RMS (3.3.5) is to be calculated
Me
Note 1 to entry: Calculation length is normally expressed in metres or millimetres.
Note 2 to entry: The calculation length is always smaller or equal to the evaluation length. One RMS value is
Me
presented per calculation length.
3.3.4
megatexture profile Z′(X)
texture profile after application of the megatexture digital filters (see Annex D) to the texture profile Z(X) (3.1.3)

ISO 13473-5:2025(en)
3.3.5
megatexture root mean square deviation of the profile
RMS
Me
root mean square (RMS) value of the ordinate values of megatexture profile Z′(X) within a calculation length l
c
l
c
RMS = ZX′ ()dX
Me
∫
l
c
where
l is the calculation length;
c
Z′(X) is the megatexture profile.
Note 1 to entry: RMS is normally expressed in millimetres (mm) in this application.
Me
Note 2 to entry: RMS is denoted R (from “rugosité quadratique” in French) in ISO 4287. However, when dealing with
Me q
pavements, RMS is preferred, since it is already one of the most used terms in pavement analysis. Furthermore,
Me
there is a risk of confusing of the terms R and R which are pronounced similarly.
q ku
Note 3 to entry: In case the texture level L (expressed in dB re. 1 µm) is given, the RMS , expressed in mm, is easily
Me Me
calculated with the equation RMS = 0,001 ∙ log(L /20). Inversely, if the RMS is given (expressed in mm), the L
Me Me Me Me
is found with the expression L = 20 ∙ log(RMS ∙ 1 000) (dB re. 1 µm). L was used as a standard indicator in the
Me Me Me
previous version of this standard.
4 Measurement instruments
4.1 Instruments in general
4.1.1 General
The technology for measuring the profile can be chosen freely by the user as long as the requirements of this
document are met. An instrument which produces a signal that is proportional to the distance between a
sensor's reference plane and a given surface sample point, can be used. Typically, the sensor would normally
be an electro-optical device or a video camera, but other devices that comply with the requirements of
ISO 13473-3 may be used. The final output shall be linearly related to the texture profile and linearity may
be obtained either in hardware or software.
The profilometer system shall also provide means of moving the sensor along or across the surface at an
elevation (vertically) which is essentially constant over at least one full wavelength. However, this is not
applicable when the profile is produced by a technique such as light sectioning where the profile and its
reference line or plane are recorded instantaneously.
The profilometer system shall meet the following specifications in accordance with ISO 13473-3:
— mobility class: mobile, fast or slow;
— texture wavelength: class EF (63 mm to 500 mm) or wider;
— minimum vertical measuring range: 60 mm;
— vertical resolution: 0,04 mm or better;
— horizontal resolution: less than or equal to the sampling interval;
— maximum sampling interval: 5 mm;
— texture wavelength range of sensor and recording system: the frequency response of the entire measuring
and data collection system shall be within ±1 dB over the entire megatexture range;
— background noise: maximum RMS value: 0,05 mm (see further in ISO 13473-3);

ISO 13473-5:2025(en)
— alignment of sensor and local slope limitation: see ISO 13473-3.
4.1.2 Performance check
Regular performance checks shall be made in accordance with ISO/PAS 13473-6.
4.1.3 Indication of invalid readings (drop-outs)
Invalid readings, also known as 'drop-outs', can occur due to the photometric properties of the surface or
shadowing of light in deep troughs of the profile. Therefore, the system shall have means to identify drop-outs.
In addition, laser diodes deteriorate over time, which can eventually result in excessive invalid readings. For
this reason, and for checking that the intensity is within the manufacturer’s specification, it is recommended
that there be a means of checking the laser intensity at certain intervals. A method for this is described in
ISO/PAS 13473-6.
5 Test surface considerations
5.1 General
The measurements shall not be taken in rain or snow. The surface shall be dry during measurements, unless
it has been established that the equipment used works equally well on a wet and dry surface. In addition, the
surface shall be clean and free of all elements which could disturb the measurements.
NOTE Measurements with an optical system are not necessarily very reliable for asphalt surfaces which have
recently been paved, since these are usually exceptionally dark and shiny. If megatexture tests are carried out during
or rather soon after laying of asphalt, distortions due to temperature gradients in the air above the test surface can
influence the measurement results.
For roads open to traffic, texture normally varies over a cross-section. In this case, the lateral position of
the measurements should be in accordance with the planned use of the results. Megatexture root mean
square deviation of the profile, RMS , can even be heavily dependent on the exact lateral position where it
Me
is measured, which can be e.g. the case if a bituminous pavement ravels or is after-compacted in the wheel
tracks. This should be assessed by means of visual observations. The lateral position should be defined as
accurately as possible and in some cases, it may be advisable to perform several runs over the same road
section in order to evaluate the uncertainty due to lateral heterogeneity, see also discussion on measurement
uncertainty in Clause 8 and Annex C.
5.2 Test lengths
The calculation length shall be 1 m (Figure 3).
NOTE This length provides a BT product (bandwidth × length) of about 16. Shorter calculation lengths do not
accurately include the longer wavelengths of the megatexture range and introduce offsets and trends not consistent
with the interpretation of texture.

ISO 13473-5:2025(en)
Key
1 measurement length
2 evaluation length
3 calculation lengths (1 m)
Figure 3 — Illustration of the concepts “measurement length”, “evaluation length” and
“calculation length”
It is recommended that measurements and evaluations (and hence calculations) are made along the entire
test section; i.e. if a profile is recorded longitudinally along the test section, 100 % of the measurement
length should be utilized.
Although a continuous measurement is the ideal, the measured profile shall include no less than five evenly
distributed profiles of at least 1 m each per 100 m test section. The calculation length shall be 1 m.
When characterizing a long test section with relatively short sample lengths, ensure that the texture within
the sample length(s) is sufficiently representative of the total length. If it is not possible to evaluate the entire
section, it is necessary to determine the minimum number of samples necessary to minimize the effect of
any suspected non-homogeneities. The selection of these samples can be done according to the procedure as
outlined in Annex F.
6 Measurement method
6.1 General
The measurements shall comprise the following operations:
a) testing of the sensitivity to vertical motion of the vehicle (only at certain intervals, see 6.2);
b) calibration of the profilometer system (see 6.3);
c) running the profilometer over the test section and measuring the pavement surface profile (see 6.4),
using a suitable test speed as specified in 6.4.
6.2 Sensitivity to vertical motion of the vehicle
Ensure that the sensor is stable at least during the measurement of a full calculation length and for all
operating speeds, or that it has some means of compensation for vertical motions. This requires that vertical
motions, e.g. those occurring at the natural suspension frequency of the sensor and/or its carrier, shall have
negligible influence, i.e. shall not violate the background noise requirements specified in 4.1.
A suitable test is to run the carrier of the measuring device on a smooth and even surface so that the tyres
roll over an object, having a height of 20 mm to 25 mm, a width of 200 mm and a length of 100 mm to

ISO 13473-5:2025(en)
150 mm, placed on the surface at the same time as the sensor does not measure the object. Rolling over the
object will excite vertical motions in the vehicle. The difference in recorded profile with and without the
object is an indication of the influence of vertical motion of the vehicle.
The testing described in this clause is necessary when the performance of the measuring system is checked
the first time, as well as at later intervals when the vehicle suspension system performance may have
changed.
A recent experiment simulating car body vibrations showed that the incurred uncertainty is not more than
[11]
4 % of the texture amplitude .
6.3 Calibration
Calibration shall be carried out by running the sensor over a special calibration surface utilizing a well-
defined profile. The vertical deviation of the calibration surface, in relation to its theoretical profile, shall
not exceed 1 % of its peak-to-peak amplitude.
The background noise when measuring stand still against a white paper with a simulated speed of 70 km/h
should be less than 0,05 mm RMS .
Me
Calibration procedures are not further specified here. They shall be designed such that the extra standard
uncertainty introduced by the procedure (in addition to the calibration surface, see above) is no worse than
10 µm RMS .
Me
Report the type of calibration used.
For testing the calculation procedures presented in this standard, the reader is referred to Annex E.
NOTE For calibration procedure and examples of calibration surfaces, refer to the principles explained in
ISO 13473-3:2002, Annex A. Consider the possibility of an adaptation to the appropriate wavelength range for
megatexture, although a calibration surface intended for the macrotexture range can be used also for megatexture if
the fundamental wavelength is at least 10 mm.
6.4 Measuring speed
The speed with which the profile is sampled shall be such that the requirements on sampling and bandwidth
are met.
NOTE Modern profilometers have bandwidths which are typically between 30 and 70 kHz, which allows
(theoretical) measuring speeds of 5 400 and 12 600 km/h, respectively. Hence way above any physical or legal speed
limitation.
6.5 Measurement of the texture profile
The texture profile shall be measured with sample intervals less than or equal to 5 mm. Sample intervals
[12]
longer than 5 mm introduce excessive error in the measurements .
NOTE The error caused by longer sampling intervals is from aliasing. Aliasing error occurs when a function is
sampled without first being low-pass filtered. Texture profiles measured with sample intervals less than or equal to
5 mm can still have aliasing but the effect on the megatexture result is not significant. When the sample interval is
greater than 5 mm, the error caused by aliasing becomes significant.
If the measured profile is used also for determining macrotexture according to ISO 13473-1, then the
maximum sampling interval shall meet the requirements in ISO 13473-1.

ISO 13473-5:2025(en)
7 Data processing
7.1 General
The measurements and calculations shall comprise the following operations:
a) eliminate the effect of drop-outs;
b) eliminate the effect of spikes;
c) resampling to a certain spatial resolution;
d) application of the megatexture digital filters to the part of the profile which will be used for the
calculation of the RMS value(s);
Me
e) calculation of the RMS value RMS of part i of the profile with calculation length l .
Me Me,i c
7.2 Preprocessing: drop-out rate and validity of measurements
Care shall be taken to eliminate invalid readings from the profile. For example, invalid measurements can
occur due to surface photometric properties or shadowing of light in deep surface troughs. Instead, the
invalid part of the profile shall be replaced with interpolated data from the nearest valid points.
As illustrated in Figure 4, several drop-outs can occur in succession. When a series of invalid samples is
preceded and followed by valid samples, each of the invalid samples shall be replaced by an interpolated
value. Linear interpolation shall be used.
With regard to linear interpolation, the invalid samples are replaced by an interpolated value z according to
i
Formula (1):
zz−
nm
z = ()im− +z (1)
i m
nm−
where
i is the sample numbers where the value is invalid;
m is the sample number of the nearest valid value before i;
n is the sample number of the nearest valid value after i;
z is the interpolated value for sample i;
i
z is the value of sample m;
m
z is the value of sample n.
n
When the in
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