Standard Test Method for Measuring the Coefficient of Retroreflected Luminance of Pavement Markings in a Standard Condition of Continuous Wetting (RL-2)

Importancia y uso:

5.1 This test method produces a measure of retroreflective efficiency (coefficient of retroreflected luminance, R_L-2) for a pavement marking system under conditions of continuous wetting. The test result depends on factors such as the pavement marking binder and optic materials, their application, wear from traffic and plowing, wetting rate, and road grade and cross slope.

5.2 The measured retroreflective efficiency under conditions of continuous wetting may be used to characterize the properties of a pavement marking on the road as water is continuously falling on it. The retroreflective efficiency of the marking under conditions of continuous wetting is almost always different than under dry conditions.

5.3 The wetting rate of 2 in./h represents the upper limit of what is meteorologically classified as heavy rainfall. Rainfall rates above 2 in./h are classified as extreme or violent, and are sometimes associated with weather such as tropical storms.

5.4 The retroreflectivity of pavement markings degrades with traffic wear and requires periodic measurement to ensure that the coefficient of retroreflected luminance under continuous wetting meets requirements and provides adequate visibility for nighttime drivers.

5.5 The continuous wetting rate as well as the roadway grade and cross slope impact the results of this test method. The user shall measure and report the rate used for testing.

5.6 The roadway grade and cross slope adjacent to the measurement area impact the results of this test method. A digital level (inclinometer) can be used to quickly measure grade and cross slope.

5.7 Results obtained using this test method should not be the sole basis for specifying and assessing the wet retroreflective effectiveness of pavement marking systems. Users should complement the results of this test method with other evaluation results, such as nighttime visual inspections.

Subcomité:

E12.10

Referida por:

D8367-21, E2177-20

Volúmen:

06.01

Número ICS:

93.080.20 (Road construction materials)

Palabras clave:

continuous wetting; pavement markings; wet retroreflection;