SIST-TS CEN/TS 15901-8:2010

Road and airfield surface characteristics - Part 8: Procedure for determining the skid resistance of a pavement surface by measurement of the sideway-force coefficient (SFCD): SKM

This Technical Specification describes a method for determining the wet-road skid resistance of a surface by measurement of the sideway-force coefficient SFCD.
The method provides a measure of the wet-road skid resistance properties of a bound surface by measurement of sideway-force coefficient at a controlled speed.
This Technical Specification covers the operation of the sideway-force Coefficient Machine (SKM) developed in Germany.
The SKM skid resistance measurement technique determines the sideway-force acting on a particular, angled wheel.
NOTE   Because wet pavement surfaces exhibit especially large differences in adhesion and constitute an almost exclusive environment in which the adhesion between tyre and pavement can drop to critically low levels, the test pavement is wetted in the region of the test wheel line during measurements.
The SKM measurement technique has been developed for Network-wide measurements of skid resistance during road monitoring and assessment of pavement surfaces on German federal motorways and highways. It is also applicable to skid resistance measurements for road construction contracts.
The skid resistance of a pavement is determined by friction measurements and measurements of pavement texture. Where measurement of pavement texture is required the standard for this measurement and the device is described in EN ISO 13473-1.

Verfahren zur Bestimmung der Griffigkeit von Fahrbahndecken durch Messung des Seitenreibungsbeiwertes (SFCD): das SKM-Griffigkeitsmessgerät

Diese Technische Spezifikation beschreibt ein Verfahren für die Bestimmung der Nassgriffigkeit von Fahr-bahndecken durch Messung des Seitenreibungsbeiwertes SFCD.
Dieses Verfahren liefert ein Maß für die Nassgriffigkeitseigenschaften einer gebundenen Oberfläche durch Messung des Seitenreibungsbeiwertes bei geregelter Geschwindigkeit.
Diese Technische Spezifikation behandelt den Betrieb des in Deutschland entwickelten Seiten-Kraft-Mess-fahrzeugs (SKM).
Beim SKM-Griffigkeitsmessverfahren wird die auf ein spezielles, schräg laufendes Rad wirkende Seitenkraft bestimmt.
Das SKM-Messverfahren wurde entwickelt, um im Rahmen der Straßenüberwachung und der Bewertung von Fahrbahndecken auf deutschen Autobahnen und Bundesstraßen das gesamte Netz umfassende Griffigkeits-messungen durchführen zu können. Es eignet sich darüber hinaus für die Anwendung bei Griffigkeitsmessun-gen für Straßenbauaufträge.
Die Griffigkeit einer Fahrbahn wird mit Hilfe von Reibungsmessungen und Messungen der Fahrbahntextur ermittelt. Das Normverfahren für die Messung der Fahrbahntextur, falls diese erforderlich ist, und das dafür zu verwendende Messgerät sind in EN ISO 13473 1 beschrieben.

Caractéristiques de surface des routes et aéroports - Partie 8: Mode opératoire de détermination de l'adhérence d'un revêtement de chaussée en procédant au mesurage du coefficient de frottement transversal (CFTD): le SKM

La présente Spécification technique décrit une méthode permettant de déterminer l’adhérence d’une chaussée mouillée par mesure du coefficient de frottement transversal (CFTD).
La méthode permet de mesurer les propriétés d’adhérence d’une couche de roulement d’une chaussée mouillée, par mesure du coefficient de frottement transversal à vitesse contrôlée.
La présente Spécification technique porte sur le fonctionnement d’un appareil de mesure du coefficient de frottement transversal (SKM) développé en Allemagne.
La technique de mesure de l’adhérence avec le SKM permet de déterminer le frottement transversal agissant sur une roue spéciale envirée avec un angle donné.
La technique de mesure SKM a été développée pour mesurer l’adhérence du réseau routier et autoroutier allemand. Elle s’applique également aux mesures de l’adhérence dans le cadre des contrats de construction routière.
L’adhérence d’une chaussée est déterminée par mesures du frottement et de la texture de la chaussée. Si une mesure de la texture de la chaussée est requise, le principe et l’appareil de mesure sont décrits dans la norme EN ISO 13473-1.

Značilnosti cestnih in vzletnih površin - 8. del: Postopek določanja torne sposobnosti vozne površine z meritvijo količnika trenja poševno vodenega kolesa (SFCD) : SKM

Ta tehnična specifikacija opisuje metodo določanja torne sposobnosti površine mokre ceste z meritvijo količnika trenja poševno vodenega kolesa SFCD. Ta metoda določa merilo lastnosti torne sposobnosti omejene površine mokre ceste z meritvijo količnika trenja poševno vodenega kolesa pri nadzorovani hitrosti. Ta tehnična specifikacija zajema delovanje opreme Coefficient Machine (SKM) za poševno vodena kolesa, razvita v Nemčiji. Tehnika merjenja torne sposobnosti SKM opreme določa bočno silo, ki deluje na določeno nagnjeno kolo. Tehnika merjenja SKM opreme je bila razvita za meritve torne sposobnosti celotne mreže med nadzorovanjem ceste in ocenjevanjem voznih površin na nemških federalnih avtocestah in cestah.  Velja tudi za meritve torne sposobnosti pri pogodbah o gradnji cest. Torno sposobnost površine določajo meritve trenja in meritve teksture površine.  Kjer se zahteva merjenje teksture površine, je standard tega merjenja in opreme opisan v EN ISO 13473-1.

General Information

• Status: Published
• Publication Date: 03-Jan-2010
• ICS: 17.040.20 - Properties of surfaces
• ICS: 93.080.10 - Road construction
• ICS: 93.120 - Construction of airports
• Technical Committee: CES - Roads
• Current Stage: 6060 - National Implementation/Publication (Adopted Project)
• Start Date: 23-Nov-2009
• Due Date: 28-Jan-2010
• Completion Date: 04-Jan-2010
• Ref Project: CEN/TS 15901-8:2009 - Road and airfield surface characteristics - Part 8: Procedure for determining the skid resistance of a pavement surface by measurement of the sideway-force coefficient (SFCD): SKM

Standards Content (Sample)

SLOVENSKI STANDARD
SIST-TS CEN/TS 15901-8:2010
01-februar-2010
=QDþLOQRVWLFHVWQLKLQY]OHWQLKSRYUãLQGHO3RVWRSHNGRORþDQMDWRUQH
VSRVREQRVWLYR]QHSRYUãLQH]PHULWYLMRNROLþQLNDWUHQMDSRãHYQRYRGHQHJDNROHVD
6)&'6.0
Road and airfield surface characteristics - Part 8: Procedure for determining the skid
resistance of a pavement surface by measurement of the sideway-force coefficient
(SFCD): SKM
Verfahren zur Bestimmung der Griffigkeit von Fahrbahndecken durch Messung des
Seitenreibungsbeiwertes (SFCD): das SKM-Griffigkeitsmessgerät
Caractéristiques de surface des routes et aéroports - Partie 8: Mode opératoire de
détermination de l'adhérence d'un revêtement de chaussée en procédant au mesurage
du coefficient de frottement transversal (CFTD): le SKM
Ta slovenski standard je istoveten z: CEN/TS 15901-8:2009
ICS:
17.040.20 Lastnosti površin Properties of surfaces
93.080.10 Gradnja cest Road construction
93.120 *UDGQMDOHWDOLãþ Construction of airports
SIST-TS CEN/TS 15901-8:2010 en,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TS CEN/TS 15901-8:2010

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SIST-TS CEN/TS 15901-8:2010


TECHNICAL SPECIFICATION
CEN/TS 15901-8

SPÉCIFICATION TECHNIQUE

TECHNISCHE SPEZIFIKATION
November 2009
ICS 93.080.20; 93.120
English Version
Road and airfield surface characteristics - Part 8: Procedure for
determining the skid resistance of a pavement surface by
measurement of the sideway-force coefficient (SFCD): SKM
Caractéristiques de surface des routes et aéroports - Partie Oberflächeneigenschaften von Straßen und Flugplätzen -
8 : Mode opératoire de détermination de l'adhérence d'un Teil 8: Verfahren zur Bestimmung der Griffigkeit von
revêtement de chaussée en procédant au mesurage du Fahrbahndecken durch Messung des
coefficient de frottement transversal: le SKM Seitenreibungsbeiwertes (SFCD): das SKM-
Griffigkeitsmessgerät
This Technical Specification (CEN/TS) was approved by CEN on 27 June 2009 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, Cyprus, Czech Republic, Denmark, Estonia, Finland,
France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,
Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.






EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2009 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 15901-8:2009: E
worldwide for CEN national Members.

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Contents Page
Foreword .3
1 Scope .4
2 Recommended uses .4
3 Terms and definitions .4
4 Safety .7
5 Essential Characteristics .7
5.1 Principle of measurements .7
5.2 Operating Principle .7
6 Key Characteristics .8
6.1 General .8
6.2 Test equipment .8
6.3 Measurement tyre .9
6.4 Load cell .9
6.5 Pavement wetting . 10
6.6 Device-specific correction factor . 11
6.7 Temperature measurement . 11
6.8 Clearance control system . 12
6.9 Measurement of distance travelled . 12
7 Test procedure . 12
7.1 Standard test conditions . 12
7.2 Prior to testing . 12
7.3 Operating conditions . 13
8 Data recording . 15
8.1 General . 15
8.2 Route assignment . 16
8.3 Device calibration value . 16
8.4 Measurement value corrections . 16
8.5 Average-value formation for 100-m intervals . 17
8.6 Measurement values submitted according to construction contracts . 17
8.7 Data formats . 18
9 Calibration . 18
9.1 General . 18
9.2 Temporary operating approval . 18
9.3 External control of test equipment . 18
9.4 Internal control of test equipment . 19
10 Precision . 19
11 Test report . 19
Annex A (informative)  Possible events for characterizing measurement records . 21
Annex B (informative)  Test certificates and test report . 23
Test certificate for temporary operating approval . 23
Test report for internal control of measurement devices used for checking the calibration . 24
Test certificate for external control measurement devices used for checking the calibration . 25
Bibliography . 26

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Foreword
This document (CEN/TS 15901-8:2009) has been prepared by Technical Committee CEN/TC 227 “Road
materials”, the secretariat of which is held by DIN.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Cyprus, Czech
Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia,
Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain,
Sweden, Switzerland and the United Kingdom.
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1 Scope
This Technical Specification describes a method for determining the wet-road skid resistance of a surface by
measurement of the sideway-force coefficient SFCD.
The method provides a measure of the wet-road skid resistance properties of a bound surface by
measurement of sideway-force coefficient at a controlled speed.
This Technical Specification covers the operation of the sideway-force Coefficient Machine (SKM) developed
in Germany.
The SKM skid resistance measurement technique determines the sideway-force acting on a particular, angled
wheel.
The SKM measurement technique has been developed for Network-wide measurements of skid resistance
during road monitoring and assessment of pavement surfaces on German federal motorways and highways. It
is also applicable to skid resistance measurements for road construction contracts.
The skid resistance of a pavement is determined by friction measurements and measurements of pavement
texture. Where measurement of pavement texture is required the standard for this measurement and the
device is described in EN ISO 13473-1.
2 Recommended uses
The SKM measuring technique is suitable for use for the following applications:
 monitoring of networks (Pavement Management);
 approval of new surfacing;
 measurements for project-level compliance;
 investigation of surface skid resistance;
 comparative measurements among different devices;
 research measurements.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
3.1
skid resistance
property of a trafficked surface that limits relative movement between the surface and the part of a vehicle tyre
in contact with the surface
NOTE Factors that contribute to skid resistance include the tyre pressure, contact area, tread pattern, and rubber
composition; the alignment, texture, surface contamination, and characteristics of the road surface; the vehicle speed; and
the weather conditions.
The skid resistance of a road surface in Europe varies seasonally. Generally, wet skid resistance is higher in winter as a
result of the effects of wet detritus and the effects of frost and wear by tyres on microtexture and macrotexture. Wet skid
resistance is lower in summer as a result of dry polishing by tyres in the presence of fine detritus.
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The change in skid resistance of a surface in service is affected by the volume of traffic and the composition of the traffic,
i.e. cars, buses, commercial vehicles of different sizes, as the tyres of these vehicles polish and/or wear away the
surfacing material in different ways. The geometry of the road will affect the change in skid resistance. Generally, tyres
polish less on straight roads than on bends.
Where the surface contains aggregate with a coating of binder, e.g. bitumen, resin or Portland cement, the skid resistance
will change as the coating is worn away by tyres.
3.2
roughness
surface texture
geometric design of the pavement surface in wavelengths ranging from a few micrometres to several
decimetres
NOTE A distinction is made between micro-, macro- and mega-roughness:
 Micro-roughness: Roughness elements with a horizontal length of less than 0,5 mm; roughness of up to 1/100 mm
strongly influences wet friction between rubber and pavement surface;
 Macro-roughness: Roughness elements with a horizontal length of 0,5 mm to 50 mm; only roughness values of up to
10 mm influence skid resistance through drainage properties;
 Mega-roughness: Roughness elements with a horizontal length of 50 mm to 500 mm. Roughness of this magnitude
can influence accumulations of water on the pavement surface (for instance, in unevenness).
3.3
operating speed
speed at which the device traverses the test surface
3.4
slip speed
relative speed between the test tyre and the travelled surface in the contact area
3.5
slip ratio
slip speed divided by the operating speed
3.6
sideway-force measurement
SKM
dynamic friction measurement technique making use of a skewed measurement wheel as described in these
technical test specifications
3.7
adhesion
transmission of forces by friction against tyre contact surfaces, which results from the interaction between
tyres and pavement surface and is influenced by surface roughness, tyre characteristics, the nature and
thickness of any intermediate medium such as water or mud, and speed
3.8
adhesion coefficient
µ
quotient of the force transmitted by adhesion to the pavement and the normal force
3.9
adhesion coefficient on a skewed wheel
µ
y
quotient of the sideway-force generated between the tyre on a skewed wheel and the pavement surface, and
the normal force
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3.10
adhesion coefficient on a skewed wheel in terms of µ
SKM
corrected adhesion coefficient on a skewed wheel
3.11
slip angle
angle between the mid-plane of the test tyre and the direction of travel projected on the contact surface in
operation
3.12
sideway-force coefficient
ratio between the horizontal force (side load) and vertical force (load) in controlled conditions
3.13
theoretical water film thickness
theoretical water film thickness of a water film between a measuring tyre and a test surface, assuming the
surface has zero texture depth
3.14
water flow rate
rate at which water is deposited on the surface to be measured in front of the test tyre
NOTE Water flow rate is expressed in litres per second (l/s).
3.15
wheelpath
part of the pavement surface where the majority of vehicle wheel passes are concentrated
3.16
nearside wheelpath
wheelpath that is closest to the edge of the road in the normal direction of travel
NOTE For countries that normally drive on the right, this is the right-hand side, and, for countries that normally drive
on the left, this is the left-hand side.
3.17
subsection
defined length of surface for which one set of the measured variables is reported by the device
3.18
test section
length of road between defined points (e.g. location references, specific features, or measured distances)
comprising a number of subsections over which a continuous sequence of measurements is made
3.19
calibration
periodic adjustment of the offset, gain and linearity of the output of a measurement method so that all the
calibrated devices of a particular type deliver the same value within a known and accepted range of
uncertainty, when measuring in identical conditions within given boundaries or range of parameters
3.20
precision
repeatability
r
maximum difference expected between two measurements made by the same machine, with the same tyre,
using the same crew on the same section of road in a short space of time, with a probability of 95 %
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3.21
precision
reproducibility
R
maximum difference expected between two measurements made by different machines with different tyres
using different crews on the same section of road in a short space of time, with a probability of 95 %
4 Safety
Safety measures shall be in place to maintain safe working practice in accordance with current regulations,
and to ensure the safety of other road users, including measures to control traffic as necessary.
NOTE The wetting of surfaces can have an effect on other users of the site and every effort should be made to
ensure that they do not have to make any sudden changes in speed or direction.
When measuring skid resistance on trafficked roads the device may operate at speeds different to normal road speeds
and as a result can create a hazard to other road users. The test speed specified when calling for tests in accordance with
this Technical Specification should take this into account.
Testing should not be carried out if there is a risk of water freezing on the road.
5 Essential Characteristics
5.1 Principle of measurements
Machines meeting this Technical Specification operate on the sideway-force principle using a special narrow
test wheel, similar to a motorcycle wheel, set an angle to the direction of travel which generates a slipping
condition as it is towed along the wetted pavement surface. The slipping force and load on the wheel are
measured. A typical device is illustrated in Figure 1.

Figure 1 — A typical SKM device (in this case BASt SKM)
5.2 Operating Principle
The sideway-force measurement procedure (SKM) determines the sideway-force acting on a defined, skewed
wheel (additional test wheel centred on the measurement vehicle’s right-hand wheel track). The measurement
principle is shown in Figure 2. The sideway-force coefficient µ is the quotient between the measured
y
sideway-force F and the known wheel load (normal force) F .
y z
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The wheel load is defined specifically by the mass of the measuring components suspended movably via
linear guides.
A controlled flow of water wets the road surface immediately in front of the test wheel, so that when the
vehicle moves forward, the test wheel slides in the forward direction along the surface.
The sideway-force coefficient essentially depends on the carriageway’s properties, measurement tyre’s skew
angle, speed, water-film thickness, road soiling and temperatures (of the tyre, applied water, carriageway
surface, atmosphere). Relevant tyre characteristics include its dimensions and type, wheel load, internal tyre
pressure and rubber properties.
The sideway-force coefficient µ is used to evaluate friction.
y
 µ = F / F

y y z
Key
1 skewed wheel
Figure 2 — Determination of the sideway-force coefficient
6 Key Characteristics
6.1 General
The minimum requirements to ensure a good repeatability and reproducibility of the devices results are listed
below.
6.2 Test equipment
The test equipment shall include the following features:
 measurement tyre (skewed);
 load cell;
 carriageway wetting unit;
 temperature measuring instruments;
 distance control system.
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6.3 Measurement tyre
 Test tyre: SKM tyre, size 3 × 20" (treadless, narrow, diagonal, motorcycle-type). Only measurement tyres
tested and certified by the “BASt (Federal Highway Research Institute) in Bergisch Gladbach” in
compliance with internal test regulations shall be used.
 Tyre properties: Shore-A hardness is determined at the “BASt” on a new tyre at 20 °C in accordance with
DIN 53505. This value shall lie between 65 and 69 points. Tyres outside this range are not supplied to
operators.
 Tyres exhibiting a ruptured or deeply scored contact surface shall not be used.
 Test wheel rim: 1,75 × 20".
 Tyre inflation pressure: (350 ± 10) kPa.
 Tyre monitoring bore: Tyres are produced with seven monitoring bores with a depth of 0,5 mm to 3,5 mm
at 0,5 mm intervals.
 Tyre abrasion: < 3 mm (the second last of the seven bores shall be clearly visible and documented).
The tyre overpressure shall be checked before every new measurement and after every interruption in
measurement; deviations shall be corrected.
To ensure comparability of measurement results, a standardized handling of the test tyres is required with
regard to storage, running in, etc.
 Tyres shall be stored on racks in a cool, dry and dark environment.
 For breaks in operation lasting more than one month, the tyre shall be stored as described above.
 Tyres older than two years shall no longer be used.
 Prior to the first measurement, new or unused tyres shall be run in for at least 20 km in the measurement
mode (including pavement wetting, etc.) on a carriageway surface providing an average friction coefficient
of 0,4 < µ < 0,7.
SKM
The measurement tyre shall be checked immediately before first use on the internal-monitoring test sections –
following the run-in phase – and at the end of the operating period by measuring, comparing and documenting
the friction on these sections.
Follow-up tyre measurements are required for a determination of friction as part of roadmonitoring and
assessment (ZEB):
Before every tyre change, perform a measurement on a route section at least 2 km long and then repeat this
measurement immediately after new, run-in tyre has been mounted. The results of this comparative
measurement should be documented, evaluated as part of internal control procedures and submitted to the
client and to the BASt.
6.4 Load cell
Temperature fluctuations between 5 °C and 50 °C around the test equipment or load cell must not lead to any
significant changes exceeding ∆µ = ± 0,005 in measurement values. The load cell’s functionality is verified as
y
part of temporary operating approval using procedures specified by the BASt.
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6.5 Pavement wetting
Because wet pavement surfaces exhibit especially large differences in adhesion and constitute an almost
exclusive environment in which the adhesion between tyre and pavement can drop to critically low levels, the
test pavement is wetted in the region of the test wheel line during measurements. The water needed for this is
transported along in a storage tank and applied to the pavement at a point in front of the test wheel. The water
quantity needs to be dosed in accordance with the vehicle’s speed in order to produce a constant, theoretical
water film thickness.
The pavement is wet via an outlet (water dispenser) located directly in front of the test wheel over its line of
travel; the outlet serves for controlled application and dosage of the water on the pavement surface. It shall
consist of a housing with brushes attached to its left-hand and right-hand sides with respect to the direction of
travel. While a measurement is in progress, these brushes shall glide over the pavement and limit the water
film’s horizontal expansion to ensure continuous wetting (refer to Figure 3 for the technical configuration). The
water supply shall be activated prior to lowering of the measurement wheel.
a) Wetting water: Tap water (the water used for testing shall be reasonably clean, free of suspended solids,
oil and salt and have no added chemicals such as wetting agents or detergents).
b) Theoretical water film thickness: 0,5 mm.
NOTE The water film thickness is called “theoretical” because it means the thickness on a perfectly dense, smooth
and horizontal pavement. The actual water film thickness depends on the pavement on which it is applied. For example on
porous pavements the water depth depends on the porosity of the pavement.
c) Water flow rate:
1) at 40 km/h 27 l/min;
2) at 60 km/h 40 l/min; Tolerances: (+ 15/- 5) %
3) at 80 km/h 53 l/min.
d) Water film width: 80 mm.
e) Wetting device: Brush length of 10 mm to 40 mm, nylon brush fibre with a thickness of about 0,4 mm and
a bundle width of at least 4 mm for adequate lateral sealing of the water dispenser in the measurement
mode.
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Dimensions in millimetres

Key
1 measuring wheel
2 water dispenser
3 maximum lateral clearance of 10 mm
4 water inlet
5 wetting lowered to carriageway level
Figure 3 — Sketch of the water dispenser
6.6 Device-specific correction factor
The influence of individual measurement vehicles on wheel load characteristic (normal force) during test runs
and deviations in value measurement are accounted for by the device-specific correction factor (refer to 8.3
and 9.2) defined by the BASt as part of temporary operating approval.
6.7 Temperature measurement
Due to the influence they exert on measurement results, the temperatures of the tyres, applied water,
carriageway surface and air shall be measured continuously. The carriageway temperature shall be measured
in front of the measurement wheel over its line of contact as seen in the direction of travel. The applied water’s
temperature shall be measured near the water outlet. The air temperature shall be measured neutrally by the
vehicle. The tyre temperature shall be measured in the middle of the tread; the temperature sensors shall not
be influenced by spray mist stemming from the applied water. The water and carriageway temperature shall
be recorded as these data are needed for measurement-value correction. The tyre and air temperature are
needed for plausibility checks (refer to Clause 7).
Contact thermometers (air, water) shall each have a measurement range of 0 °C to 60 °C, measurement
accuracy of 0,5 °C and resolution of 0,1 °C. Pyrometers for measuring tyre and carriageway temperature shall
meet the requirements of VDI/VDE 3511 Blatt 4. The pyrometers shall each have a measurement range of
0 °C to 50 °C, measurement accuracy of 1,5 °C and resolution of 1 °C.
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6.8 Clearance control system
Serving to monitor the spacing between the measurement vehicle and carriageway edge, the clearance
control system comprises sensors, value recording equipment and a display unit indicating any necessary
steering corrections to the driver. The clearance parameter is defined as the interval between the
measurement line passing through the tyre tread’s middle and the lane’s right-hand boundary (usually
considered as the white, continuous borderline’s left edge).
The clearance sensor shall have a measurement range of at least 1,20 m starting from the right-hand
boundary (left edge of border line).
Clearance control measurements shall have a resolution of 1 cm. Values measured during static tests shall
have a maximum deviation of ± 2 cm. Deviations from the target measurement line shall be indicated to the
driver in maximum steps of 5 cm (centred zone of ± 2,5 cm).
Clearance data shall be updated at least every 5 m and recorded continuously.
6.9 Measurement of distance travelled
The maximum permissible error in measuring distance travelled is 0,5 % during tests on flat stretches at
constant speed.
7 Test procedure
7.1 Standard test conditions
Table 1 — Standard test conditions
Air temperature > 5 °C
> 5 °C and < 50 °C
Pavement temperature
(For Road Monitoring and assessment (ZEB) – testing season:
May till October)
Water temperature > 8 °C and < 25 °C
Pavement status no pollution
Test tyre
...