prEN 12899-6
(Main)Fixed vertical road traffic signs - Part 6: Visual performance of retroreflective sheeting materials
Fixed vertical road traffic signs - Part 6: Visual performance of retroreflective sheeting materials
This standard specifies the visual performance for road users of retroreflective sheeting materials, as expressed by their retroreflection in vehicle headlamp illumination and their reflection and chromaticity in daylight.
Ortsfeste, vertikale Straßenverkehrszeichen - Teil 6: Visuelle Anforderungen an retroreflektierendes Beschichtungsmaterial
Diese Norm legt die visuellen Anforderungen der Verkehrsteilnehmer an retroreflektierende
Beschichtungsmaterialien fest. Die visuellen Anforderungen ergeben sich aus der Retroreflexion von Licht aus
Fahrzeugscheinwerfern sowie der Reflexion und dem Farbwert bei Tageslicht.
Signaux fixes de signalisation routière verticale - Partie 6 : Performances visuelles des matériaux de films rétroréfléchissants
La présente norme spécifie les performances visuelles des usagers de la route s'agissant des matériaux de films rétroréfléchissants, qui sont exprimées par leur rétroréflexion dans l'éclairage des phares du véhicule et leur réflexion et chromaticité de jour.
Stalna vertikalna cestna signalizacija - 6. del: Vizualne zahteve za retroreflektivni premazne materiale
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
oSIST prEN 12899-6:2009
01-april-2009
Stalna vertikalna cestna signalizacija - 6. del: Vizualne zahteve za retroreflektivni
premazne materiale
Fixed vertical road traffic signs - Part 6: Visual performance of retroreflective sheeting
materials
Ortsfeste, vertikale Straßenverkehrszeichen - Teil 6: Visuelle Anforderungen an
retroreflektierendes Beschichtungsmaterial
Ta slovenski standard je istoveten z: prEN 12899-6
ICS:
93.080.30 Cestna oprema in pomožne Road equipment and
naprave installations
oSIST prEN 12899-6:2009
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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oSIST prEN 12899-6:2009
EUROPEAN STANDARD
DRAFT
prEN 12899-6
NORME EUROPÉENNE
EUROPÄISCHE NORM
December 2008
ICS 93.080.30
English Version
Fixed vertical road traffic signs - Part 6: Visual performance of
retroreflective sheeting materials
Ortsfeste, vertikale Straßenverkehrszeichen - Teil 6:
Visuelle Anforderungen an retroreflektierendes
Beschichtungsmaterial
This draft European Standard is submitted to CEN members for enquiry. It has been drawn up by the Technical Committee CEN/TC 226.
If this draft becomes a European Standard, 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.
This draft European Standard was established by CEN 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 Management Centre has the
same status as the official versions.
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.
Recipients of this draft are invited to submit, with their comments, notification of any relevant patent rights of which they are aware and to
provide supporting documentation.
Warning : This document is not a European Standard. It is distributed for review and comments. It is subject to change without notice and
shall not be referred to as a European Standard.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2008 CEN All rights of exploitation in any form and by any means reserved Ref. No. prEN 12899-6:2008: E
worldwide for CEN national Members.
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Contents
Foreword . 3
1 Scope . 6
2 Normative references . 6
3 Terms, definitions, symbols and abbreviations . 6
4 Retroreflection of retroreflective sheeting materials . 7
4.1 Introduction . 7
4.2 Derivation of the coefficient of retroreflection for signal and contrast colours . 8
4.3 Application classes for signal colours . 8
4.4 Performance classes for signal colours . 10
4.5 Derivation of the R index for secondary datum axes . 11
A
Requirements for contrast colours . 12
4.6 Requirements for contrast colours . 12
5 Daytime luminance factor and chromaticity of retroreflective sheeting materials . 12
Annex A (normative) Methods for deriving the coefficient of retroreflection R and its symmetries . 16
A
A.1 General . 16
A.2 Method for deriving R (αα,ββ) values by thorough testing . 16
ααββ
A,C
A.3 Method of deriving R (αααα,ββββ) values by simplified testing . 19
A,C
A.4 Establishment of datum axis reversal symmetry . 19
A.5 Establishment of datum axis rotation symmetry . 20
A.5.1 General . 20
A.5.2 Optical Elements with complete rotational symmetry . 20
A.5.3 Optical Elements without complete rotational symmetry . 20
Annex B (normative) Colorimetric testing . 21
B.1 Luminance factor and chromaticity of non-fluorescent materials . 21
B.1.1 General . 21
B.1.2 Reference method for microprismatic sheeting materials . 21
B.1.3 Secondary method for microprismatic sheeting materials . 21
B.2 Luminance factor and chromaticity of fluorescent materials . 22
Annex C (informative) Guidelines for the selection of application and performance classes . 23
C.1 Introduction . 23
C.2 Application classes . 23
C.3 Performance classes . 24
C.4 Vehicles other than the passenger car . 25
C.5 Signs at other locations . 26
C.6 Other factors . 27
C.7 Guidelines . 28
Bibliography . 31
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Foreword
This document (prEN 12899-6:2008) has been prepared by Technical Committee CEN/TC 226 “Road equipment”,
the secretariat of which is held by AFNOR.
This document is currently submitted to the CEN Enquiry.
This European Standard consists of the following Parts under the general title:
Fixed, vertical road traffic signs —
Part 1: Fixed signs
Part 2: Transilluminated traffic bollards (TTB)
Part 3: Delineator posts and retroreflectors
Part 4: Factory production control
Part 5: Initial type testing
Part 6: (This part) Visual performance of retroreflective sheeting materials
Annexes A and B are normative.
The visual performance of retroreflective sheeting materials is is dependent on the properties of retroreflection,
luminance factor and chromaticity. Retroreflection is the relevant characteristic for the legibility of road signs during
night time driving, while luminance factor and chromaticity are relevant characteristics for the legibility of signs during
the daytime (and for illuminated signs at night).
Test methods for retroreflection are provided in Annex A and for luminance factor and chromaticity in Annex B. These
Annexes are of a complex technical nature, as they deal with retroreflective sheeting materials of both known
technologies - glass beaded and microprismatic - and because the fluorescence of fluorescent sheeting materials has
been taken into account in Annex B. These Annexes are primarily intended to be studied by experts working at test
laboratories.
The requirements for retroreflection are provided in clause 4. A distinction is made between the situations in which a
road sign has to be read and the level of luminance to be expected from a sign with a particular sheeting material in
those situations. The situations are grouped into a number of application classes while the level of luminance is
described by means of an R index. A number of classes of convenience called performance classes are defined by
A
means of the R index.
A
This system of classes is intended as a tool for trading in the sense that the manufacturer of a retroreflective sheeting
material can supply adequate documentation of the performance of his product, which is to be used by the purchaser of
sheeting materials to select products that are suitable for particular purposes. The system of classes is complex - and
has to be complex - in order to make good use of retroreflection. A single material cannot supply optimum or even
adequate sign legibility in all applications, but some materials can do so in some applications and other materials in
other applications.
However, it is assumed that the purchaser has some guidance through national regulations or tender specifications that
define the application and performance classes for individual road signs or types or uses of road signs. Clause 4 is
therefore intended primarily for the manufacturers of retroreflective sheeting materials and for national legislators
perhaps assisted by specialists.
National regulations or tender specifications will reflect a national policy that may take several matters into account.
Annex C is intended to provide guidance for formulating such a policy.
3
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The requirements for the luminance factor and the chromaticity of retroreflective materials are provided in clause 5.
These are formulated in a simple manner by means permissible values for the luminance factor and permissible
chromaticity boxes for the chromaticity.
4
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Introduction
A legend or a symbol on a sign face is presented in one colour against the background of another colour. One of these
colours is generally brighter than the other and is called the signal colour, while the darker colour is called the contrast
colour; refer to 3.1 and 3.2.
Some bright colours serve generally as signal colours, while some dark colours generally serve as contrast colours. A
few colours may sometimes serve as signal and sometimes as contrast colours. The supplier of a sheeting material
may decide which colours he wants to offer as signal and/or contrast colours.
The signal colour is considered to be the more important in terms of retroreflective performance. This has implications
for the methods for deriving the coefficient of retroreflection R and for the requirements for retroreflection.
A
The methods for deriving the coefficient of retroreflection R are provided in Annex A. These methods are to be used
A
for all sheeting materials regardless of their technology and the results may differ from those obtained with other test
methods (for instance the simplified test method conventionally used for glass beaded sheeting materials).
The requirements for retroreflection are provided in clause 4. For signal colours, the requirements are expressed by
technical classes for application and performance. For contrast colours, the requirements are expressed by the
contrast to signal colours.
Some guidelines for the selection of application and performance classes are offered in the informative Annex C.
It is a particular feature of retroreflection that it has limitations. Consequently, application and performance classes
cannot in practice be selected independently of each other. Additionally, the application class which is the most
suitable for drivers of small vehicles may be less suitable for drivers of large vehicles.
Annex C is therefore intended as the basis for forming a policy for retroreflective road signs, in which conflicting
interests are weighed against each other in a suitable manner.
The daytime performance is described in a conventional manner by means of requirements for the luminance
factor and the chromaticity. The requirements are provided in clause 5 and the test methods in Annex B.
5
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1 Scope
This standard specifies the visual performance for road users of retroreflective sheeting materials, as expressed by
their retroreflection in vehicle headlamp illumination and their reflection and chromaticity in daylight.
2 Normative references
The following referenced documents are indispensable for the application 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.
IEC 60050-845, International Electrotechnical Vocabulary.Lighting
CIE 15:2004, Colorimetry
CIE 54.2, Retroreflection: definition and measurement
3 Terms, definitions, symbols and abbreviations
For the purpose of this standard the following terms, definitions, symbols and abbreviations given in IEC 60050-845
and CIE 54.2 and the following apply:
3.1
signal colour
brightest colour of the sign face of a retroreflective sign
NOTE: The signal colour is white for most signs, but may be yellow, orange, fluorescent yellow or fluorescent
yellow/green for some.
3.2
contrast colour
any colour of the sign face of a retroreflective sign that is not the signal colour
3.3
coefficient of retroreflection (of a plane retroreflecting surface), symbol R ,
A
-1 -2
unit cd⋅⋅⋅⋅lx ⋅⋅⋅⋅m
ratio of the luminous intensity of a plane retroreflecting surface in the direction of observation to the illuminance at
the retroreflecting surface measured on a plane perpendicular to the direction of the incident light in proportion to
the area of the retroreflecting surface.
NOTE The value of the coefficient of retroreflection depends in principle on four angles, this being the number of
angles needed to describe the directions of observation and incident light relative to the retroreflecting surface.
Refer to CIE 54.2 for the definition of such angles and their combination into angular systems.
3.4
R (αααα,ββββ) value
A,C
calculated value of the coefficient of retroreflection R for a combination of the observation angle α and the
A
entrance angle β
NOTE 1 Definitions of the observation angle α and the entrance angle β are provided in CIE 54.2. A value of the
observation angle α relates to the distance to a road sign and a value of the entrance angle β relates to the
obliqueness at which the sign is illuminated.
NOTE 2 The R (α,β) value is calculated from various R measurements in which two additional angles have
A,C A
been varied. The calculation is such that the R (α,β) value is a reasonable representation of the coefficient of
A,C
retroreflection R taking account of variation in vehicle geometries and location of signs.
A
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3.5
application class
class defining the geometrical circumstances in which a road sign is to be read by drivers of passenger cars,
comprising a number of values of the observation angle α and the entrance angle β
3.6
R index
A
index providing a single measure of the general level of retroreflective performance of a sheeting material for the
geometrical circumstances of an application class
NOTE The R index value of a particular sheeting material will in general depend on the application class.
A
3.7
performance class
classification based on the R index value of a signal colour for a given application class
A
3.8
datum axis
direction relative to a retroreflective material indicating the orientation with which the material is to be
mounted on a road sign so that the datum axis is pointed upwards
NOTE 1 A datum axis can be indicated by a datum mark on the material or can be the direction of the roll of the
material or can be indicated in other ways and shall be declared by the manufacturer of the sheeting material.
NOTE 2 If the manufacturer declares more than one datum axis, one datum axis is distinguished as the primary
datum axis while the others are secondary datum axes.
4 Retroreflection of retroreflective sheeting materials
4.1 Introduction
The retroreflection of a retroreflective sheeting material is in principle determined by R values. The R values shall
A A
be measured in accordance with 4.2, and shall be used to derive R (α,β) values by calculation as also accounted
A,C
for in 4.2 by reference to Annex A.
Refer to 3.3 for a definition of R and to 3.4 for a definition of R (α,β). Further explanation of the purpose of
A A,C
reduction of a set of measured R values to a smaller set of calculated R (α,β) values can be found in 4.2 and
A A,C
Annex C.
The performance of a retroreflective sheeting material is judged by comparison of R (α,β) values to reference
A,C
R (α,β) values. The reference R (α,β) values are introduced in 4.3 which also provides some explanation.
A,R A,R
Further explanation can be found in Annex C.
This comparison is carried out for signal colours of a sheeting material, while contrast colours are considered in a
different manner to be explained later. Signal and contrast colours are defined in 3.1 and 3.2 respectively.
The comparison includes a selection of (α,β) cases that corresponds to a certain application of the sheeting
material in terms of a distance range and an entrance angularity. Such a selection defines an application class and
several of these are introduced in 4.3.
The method of comparison is accounted for in 4.4. The result of a comparison is an R index, which is used to
A
determine a performance class by comparison with a scale of values as also accounted for in 4.4. Both the R
A
index and the performance class is specific for a particular signal colour of the sheeting material and a particular
application class.
An R index for a particular signal colour is in principle valid for a particular datum axis and has relevance only if
A
the sheeting material is finally employed with this datum axis pointed upwards. Refer to 3.8 for a definition of datum
axis.
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The manufacturer of a sheeting material shall declare the datum axis. The manufacturer can declare more than one
datum axis. If so, one datum axis is distinguished as the primary datum axis while the others are secondary datum
axes. Secondary datum axes are defined by clockwise rotations relative to the primary datum axis.
A specific way to declare more than one datum axis is to declare datum axis reversal symmetry or datum axis rotation
symmetry, meaning respectively that the material can be applied with a 180° rotation, or with any rotation.
The derivation of R index for secondary datum axes is accounted for in 4.5.
A
A contrast colour is judged by means of the ratio between the R (α,β) value of the contrast colour and R (α,β)
A,C A,C
value for the signal colour white. This ratio is requested to be in a permissible range that is specific to the contrast
colour in question, refer to 4.6.
4.2 Derivation of the coefficient of retroreflection for signal and contrast colours
A sign face is assumed to combine a signal colour and a contrast colour, refer to 3.1 and 3.2. The retroreflectivity of
these different colours is represented by different values of R (α,β).
A,C
The expression R (α,β) means the R value for a particular combination of the observation angle α and the
A,C A
entrance angle β, refer to 3.4. R (α,β) values shall be obtained by the methods provided in Annex A, measuring
A,C
R for one or more geometrical situations.
A
4.3 Application classes for signal colours
The classifications are based on comparison of R (α,β) values of the signal colour with the R (α,β) reference
A,C A,R
values provided in Table 1 for particular cases of α and β.
Table 1 - R (αααα,ββββ) reference values for white parts of road signs
A,R
Observation
Entrance angle β
angle α
5° 15° 30° 40°
66,4 64,4 57,7 51,0
0,20°
32,9 31,9 28,6 25,3
0,33°
18,4 17,8 16,0 14,2
0,50°
11,5 11,1 9,99 8,84
0,70°
6,97 6,76 6,06 5,36
1,00°
3,95 3,83 3,44 3,04
1,50°
2,64 2,56 2,30 2,03
2,00°
NOTE 1 The observation angle α relates to the distance between a sign and a vehicle (small α corresponds to a
large distance), while the entrance angle β relates to the obliqueness with which the headlight of the vehicle
illuminates the sign.
2
NOTE 2 The R (α,β) reference values correspond to a constant sign luminance of 1 cd/m . These values are
A,R
-1,4
provided in Table 1 and come from the function R = 6,99×α ×cosβ.
A
The comparison between R (α,β) values of the signal colour and R (α,β) reference values is limited to one or
A,C A,R
more selections of cases of α and β as indicated in Table 2. These selections correspond to the following
application classes:
- A11 : long distance, narrow entrance angularity
(up to 5° entrance angularity)
- A12 : long distance, medium entrance angularity
(up to 15° entrance angularity)
- A21 : medium distance, narrow entrance angularity
(up to 5° entrance angularity)
- A22 : medium distance, medium entrance angularity
(up to 15° entrance angularity)
- A23 : medium distance, wide entrance angularity (up to 30° entrance angularity)
- A31 : short distance, narrow entrance angularity
(up to 5° entrance angularity)
- A32 : short distance, medium entrance angularity
(up to 15° entrance angularity)
- A33 : short distance, wide entrance angularity
(up to 30° entrance angularity)
- A34 : short distance, extra wide entrance angularity (up to 40° entrance angularity)
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Long, medium and short distances relate to ranges of distances that are relevant for signs on different types of
roads depending on driving speeds and other matters. Narrow, medium, wide and extra wide entrance angularity
refers to the need to ensure performance in situations with oblique light incident on the signs.
Two or more classes of entrance angularity can be applied simultaneously.
For example: in recognition that the majority of signs are positioned at small entrance angles, the 5° entrance
angularity class can be applied with a high performance class. Simultaneously a lower performance class can be
applied for the 15° and 30° entrance angularity class, as there are likely to be some signs viewed at larger entrance
angles. This would emphasise the performance requirement for the majority of signs that are positioned at small
entrance angles and still require a level of performance for those signs viewed at wider entrance angles.
The classes A11, A21 and A31 shall only be applied in combination with other application classes with wider
entrance angularity, as the narrow entrance angularity is not sufficient in itself. Refer to C.7 for further information.
Table 2 - Selections of cases for application classes A11, A12, A21, A22, A23, A,31, A32, A33 and
A34
Class A11 Class A12
α β β
5° 5° 15°
66,4 66,4 64,4
0,20°
32,9 32,9 31,9
0,33°
0,50° 18,4 18,4 17,8
11,5 11,5 11,1
0,70°
1,00° 6,97 6,97 6,76
1,50° - - -
2,00° - - -
Class A21 Class A22 Class A23
α β β β
5° 5° 15° 5° 15° 30°
- - - - - -
0,20°
32,9 32,9 31,9 32,9 31,9 28,6
0,33°
18,4 18,4 17,8 18,4 17,8 16,0
0,50°
11,5 11,5 11,1 11,5 11,1 9,99
0,70°
6,97 6,97 6,76 6,97 6,76 6,06
1,00°
3,95 3,95 3,83 3,95 3,83 3,44
1,50°
- - - - - -
2,00°
Class A31 Class A32 Class A33 Class A34
α β β β β
5° 5° 15° 5° 15° 30° 5° 15° 30° 40°
- - - - - - - - - -
0,20°
- - - - - - - - - -
0,33°
18,4 18,4 17,8 18,4 17,8 16,0 18,4 17, 16,0 14,2
0,50°
8
0,70° 11,5 11,5 11,1 11,5 11,1 9,99 11,5 11, 9,99 8,84
1
6,97 6,97 6,76 6,97 6,76 6,06 6,97 6,7 6,06 5,36
1,00°
6
3,95 3,95 3,83 3,95 3,83 3,44 3,95 3,8 3,44 3,04
1,50°
3
2,64 2,64 2,56 2,64 2,56 2,03 2,64 2,5 2,30 2,03
2,00°
6
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4.4 Performance classes for signal colours
For a particular signal colour and application class, an R index is derived in three steps:
A
I: the ratios are formed between R (α,β) values of the signal colour and R (α,β) reference values
A,C A,R
for each of the cases in the selection corresponding to the class
II: for each column of β cases within the selection, the harmonic mean of the ratios formed in step I
is formed
III: the R index value is selected as the smallest of the harmonic means formed in step II.
A
The harmonic means to be determined in step II include five ratios R , R , R , R and R . The harmonic mean is
1 2 3 4 5
determined as 5/(1/ R +1/ R +1/R +1/R +1/R ).
1 2 3 4 5
NOTE The R index is a single measure of the general level of retroreflection of a sheeting material as compared
A
to the R (α,β) reference values. An R index applies for a particular application class; the value will in general
A,R A
depend on the application class.
EXAMPLE 1 (applies to application class A23): The R index is determined in three steps. In step I the ratios
A
between the R (α,β) reference values and the R (α,β) values of the signal colour are formed, in step II the
A,R A,C
harmonic means of the ratios are formed for each relevant case of the entrance angle β and in step III the smallest
of these harmonic means is selected.
R (α,β) reference values R (α,β) values of the step I: Ratios
A,R A,C
signal colour
Observation
Entrance angle β Entrance angle β Entrance angle β
angle α
5° 15° 30° 5° 15° 30° 5° 15° 30°
- - - - - - - - -
0,20°
32,9 31,9 28,6 432 370 183 13,1 11,6 6,40
0,33°
0,50° 18,4 17,8 16,0 340 306 151 18,5 17,2 9,44
11,5 11,1 9,99 230 198 97,4 20,0 17,8 9,75
0,70°
6,97 6,76 6,06 103 89,1 44,0 14,8 13,2 7,26
1,00°
3,95 3,83 3,44 28,2 25,2 11,3 7,14 6,58 3,28
1,50°
2,00° - - - - - - - - -
step II: harmonic means 12,9 11,7 6,19
step III: minimum 6,19
For a particular application class, the R index is used to decide the performance class in accordance with the
A
minimum requirements of Table 3.
Table 3 - Minimum requirements for performance classes
performance signal colour
class white yellow orange
P0 NPD *) NPD *) NPD *)
P1
R index ≥ 1,4 R index ≥ 1,0 R index ≥ 0,7
A A A
P2
R index ≥ 2,0 R index ≥ 1,4 R index ≥ 1,0
A A A
P3
R index ≥ 2,8 R index ≥ 2,0 R index ≥ 1,4
A A A
P4
R index ≥ 4,0 R index ≥ 2,8 R index ≥ 2,0
A A A
P5
R index ≥ 5,6 R index ≥ 4,0 R index ≥ 2,8
A A A
P6
R index ≥ 8,0 R index ≥ 5,6 R index ≥ 4,0
A A A
P7
R index ≥ 11,3 R index ≥ 8,0 R index ≥ 5,6
A A A
P8
R index ≥ 16,0 R index ≥ 11,3 R index ≥ 8,0
A A A
*) no performance determined
EXAMPLE 2: An R index of 6,19 for the signal colour white leads to performance class P5.
A
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4.5 Derivation of the R index for secondary datum axes
A
For the signal colour white, the R index shall be derived independently in accordance with 4.4 for the primary
A
datum
...
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