Significance and Use
The quality of the stripe is determined by the coefficient of retroreflected luminance, RL, and depends on the materials used, age, and wear pattern. These conditions shall be observed and noted by the user.
Under the same conditions of illumination and viewing, larger values of RL correspond to higher levels of visual performance.
Retroreflectivity of pavement (road) markings degrade with traffic wear and require periodic measurement to ensure that sufficient line visibility is provided to drivers.
For a given viewing distance, measurements of RL made with a retroreflectometer having a geometry corresponding to that viewing distance are a good indicator of the visual ranking of material measured.
As specified by CEN, the measurement geometry of the instrument is based on a viewing distance of 30 m, a headlight mounting height of 0.65 m directly over the stripe, and an eye height of 1.2 m directly over the stripe.
It shall be the responsibility of the user to employ an instrument having the specified observation and entrance angles.
1.1 This test method covers measurement of the retroreflective properties of horizontal pavement marking materials containing retroreflecting beads, such as traffic stripes and surface symbols, using a portable retroreflectometer that can be placed on the road delineation to measure the retroreflection at a prescribed geometry.
Note 1—The restriction to bead based materials is for the purpose of ensuring a sufficiently gradual optical response function (from points of the source aperture to points of the receiver aperture) to allow generous sized instrument source and receiver apertures.
1.2 The entrance and observation angles of the retroreflectometer affect the readings. As specified by the European Committee for Standardization (CEN), the entrance and observation angles shall be 88.76° and 1.05°, respectively.
1.3 This test method is intended to be used for field measurement of pavement markings but may be used to measure the performance of materials on sample panels before placing the marking material in the field.
1.4 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.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
CENEN1436 Road Marking Materials--Road Marking Performance for Road Users Available from European Committee for Standardization (CEN), 36 rue de Stassart, B-1050, Brussels, Belgium, http://www.cenorm.be.
D4061 Test Method for Retroreflectance of Horizontal Coatings
D6359 Specification for Minimum Retroreflectance of Newly Applied Pavement Marking Using Portable Hand-Operated Instruments
E177 Practice for Use of the Terms Precision and Bias in ASTM Test Methods
E284 Terminology of Appearance
E691 Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method
E809 Practice for Measuring Photometric Characteristics of Retroreflectors
pavement markings; portable retroreflectometers; retroreflection; CEN (Comite Europeen de Normalization); European Committee for Standardization; Geometric analysis--paints/related coatings/materials; Pavement marking materials; Portable retroreflectometers; Retroreflective marking materials; Symbols; Traffic paint; Traffic stripes;
ICS Number Code 93.080.20 (Road construction materials)
ASTM International is a member of CrossRef.
Citing ASTM Standards
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