ASTM E2177-01(2009)

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Designation:E2177–01 Designation: E2177 – 01 (Reapproved 2009)
Standard Test Method for
Measuring the Coefficient of Retroreflected Luminance (R )
L
of Pavement Markings in a Standard Condition of Wetness
This standard is issued under the fixed designation E2177; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope
1.1 This test method covers the measurement of the wet retroreflective (R ) properties of horizontal pavement marking
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materials, such as traffic stripes and road surface symbols, using a portable or mobile retroreflectometer that can be placed on or
before the road marking to measure the retroreflection at the prescribed geometry.
1.2 This method of measuring the wet retroreflective properties (R ) of pavement markings measures the wet retroreflectivity
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in a standard condition of wetness (see Fig. 1).
1.2.1 Discussion—This test condition typically exists ( 1) after a rainfall has ended and the pavement markings are still wet or
(2) as the markings are wet from dew or humidity.
1.3 Retroreflective performance obtained with this test in conditions of wetness does not necessarily relate to how markings
perform in conditions of rain, that is, as markings are being rained upon.
NOTE 1—Test Method E2176 defines a method to use to measure the performance of pavement markings in conditions of simulated rain.
1.4 This test method specifies the use of portable or mobile reflectometers that can measure pavement markings in accordance
withTestMethodE1710. Theentranceandobservationanglesrequiredoftheretroreflectometerinthistestmethodarecommonly
referred to as “30 meter geometry.”
1.5This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
FIG. 1 Illustration of Measurement
2. Referenced Documents
2.1 ASTM Standards:
D6359 Specification for Minimum Retroreflectance of Newly Applied Pavement Marking Using Portable Hand-Operated
Instruments
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
This test method is under the jurisdiction ofASTM Committee E12 on Color andAppearance and is the direct responsibility of Subcommittee E12.10 on Retroreflection.
Current edition approved Dec. 10, 2001. Published February 2002. DOI: 10.1520/E2177-01.
Current edition approved Dec. 1, 2009. Published December 2009. Originally approved in 2001. Last previous edition approved in 2001 as E2177 - 01. DOI:
10.1520/E2177-01R09.
Reference ASTM E1710 “Standard Test Method for Measurement of Retroreflective Pavement Markings with CEN-Prescribed Geometry Using a Portable
Retroreflectometer.” The standard measurement condition is intended to represent the angles corresponding to a distance of 30 m for the driver of a passenger car with an
eye height of 1.2 m and a headlight height of 0.65 m above the road. See Appendix X1.
For referencedASTM standards, visit theASTM website, www.astm.org, or contactASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
E2177 – 01 (2009)
EB965Test Method for Measuring Pavement Macrotexture Depth Using a Volumetric Technique Specification for High
Performance Tin-Coated Annealed Copper Wire Intended for Electrical and Electronic Application for Solderability
E1710 Test Method for Measurement of Retroreflective Pavement Marking Materials with CEN-Prescribed Geometry Using a
Portable Retroreflectometer
E2176 Test Method for Measuring the Coefficient of Retroreflected Luminance of Pavement Markings in a Standard Condition
of Continuous Wetting (R )
L-Rain
2.2 Other Standard:
CEN–EN 1436 Road Marking Materials—Road Marking Performance for Road Users
3. Terminology
3.1 coeffıcient of retroreflected luminance, R L, n—the ratio of the luminance, L, of a projected surface to the normal
L
-2
illuminance, E, at the surface on a plane normal to the incident light, expressed in candelas per square metre per lux [(cd·m )/lx].
Because of the low luminance of pavement markings, the units commonly used are millicandelas per square metre per lux
-2
[(mcd·m )/lx].
3.2 condition of wetnesscondition of wetness, n—the test condition is created by liberally wetting the road marking and waiting
a certain time period after wetting for water to run off.
3.2.1 Discussion—Similar conditions exist when road markings are wet or damp such as typically found after a rain has ended
or from dew and high humidity.
3.3 mobile retroreflectometermobile retroreflectometer, n—a retroreflectometer that has been mounted to a vehicle for purposes
of taking measurements while the vehicle is moving.
3.4 portable retroreflectometerportable retroreflectometer, n—an instrument that can be used in the field or laboratory for
measuring the coefficient of retroreflected luminance, R .
L
3.5 “recovery method” or “bucket method” , n—alternative names commonly used to describe this test method for achieving
measurements in condition of wetness.
3.6 R L-wet, n—the retroreflectance value, R , obtained 45 s after wetting. (See Fig. 2.)
L-wet L
FIG. 2 Definition of R
L-Wet
4. Significance and Use
4.1 The nighttime performance of pavement markings is determined by the coefficient of retroreflected luminance, R ,beitdry
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or wet, and depends on the materials used, age, and wear pattern. These conditions shall be observed and noted by the user.
4.2 Under the same conditions of headlight illumination and driver’s viewing, larger values of R correspond to higher levels
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of visual performance at corresponding geometry.
4.3 Thepavementmarking’smeasuredperformanceinthestandardconditionofwetnessisusedtocharacterizetheperformance
of the marking on the road when wet.
4.4 Newly installed pavement markings may have a natural surface tension or release agents that prevent wetting of the product
by water.The water will tend to “bead up” on the marking.This “non wetting” condition is usually short lived. Pavement markings
that have been on the road for one month prior to testing usually do not exhibit this non-wetting phenomenon. (Warning–This
phenomenon produces an interference when assessing the wet characteristics of a pavement marking. Attempts to measure
markings with this surface “non-wetting” or “beading” of the water may give higher values.)
4.5 The retroreflectivity, R , of pavement (road) markings degrades with traffic wear and requires periodic measurement to
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ensure that sufficient line visibility is provided to drivers. For example see Specification D6359 for dry retroreflectivity
requirements.
Available from European Committee for Standardization (CEN), 36 rue de Stassart, B-1050, Brussels, Belgium, http://www.cenorm.be.
E2177 – 01 (2009)
4.6 For a given viewing distance, measurements of R made with a retroreflectometer having a geometry corresponding to that
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viewing distance are a good indicator of the visual ranking of the material measured.
4.7 As specified by Test Method E1710, the measurement geometry of the instrument is based on a viewing distance of 30 m,
an eye height of 1.2 m and a headlight mounting height of 0.65 m (see Appendix X1).
4.8 It shall be the responsibility of the user to employ an instrument having the specified observation and entrance angles.
5. Apparatus
5.1 Portable or Mobile Retroreflectometer—The reflectometer must comply with Test Method E1710.
5.2 Stopwatch or Watch, with second hand.
5.3 Water, for wetting the pavement marking.
5.3.1 A portable hand sprayer (garden sprayer) may be used to wet the pavement marking to create the wet condition. The
portable hand sprayer shall have an adjustable nozzle. A battery operated unit works well.
5.3.2 Alternatively a bucket may be used to create the wet condition by pouring the water over the marking. Approximately 2
to 5 L of water are needed.
5.3.3 The water shall be clean tap water.
6. Sampling
6.1 The number of readings to be taken at each test location and the spacing between test locations shall be specified by the
user.
6.2 It is common to take less
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