ASTM International

Standard Test Method for Measuring the Coefficient of Retroreflected Luminance of Pavement Markings in a Standard Condition of Continuous Wetting (RL-2)
 N E2832

Annotation

This test method covers a measurement of the wet retroreflective (RL-2) properties of horizontal pavement marking materials, such as traffic stripes and road surface symbols. A standardized method utilizing a standardized continuous wetting device and a portable retroreflectometer is described to obtain measurements of the wet retroreflective properties of horizontal pavement markings.

Retroreflective performance obtained with this test in a standardized condition of continuous wetting does not necessarily relate to how markings perform in all conditions of natural rain.

NOTE 1—Test Method E2177 may be used to describe the retroreflective properties of pavement markings in conditions of wetness, such as after a period of rain.

This test method is suitable for measurements made in the laboratory and in the field when the necessary controls and precautions are followed.

This test method specifies the use of external beam retroreflectometers conforming to Test Method E1710.2 The entrance and observation angles required of the retroreflectometer in this test method are commonly referred to as "30 meter geometry."2

The test method excludes the effects of rain between the vehicle and the marking.

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.