1.1 This test method covers a measurement of the wet retroreflective (R_L-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.

1.2 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.

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

1.4 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

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

1.6 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.

1.7 The values stated in SI units are to be regarded as standard. The values given in parentheses are for information only.

1.8 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, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.9 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.