ASTM E 2176 : 2001

1.1 This test method covers the measurement of the wet retroreflective (R_L) properties of horizontal pavement marking 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 of the wet retroreflective properties (R_L) of pavement markings utilizes a method of continuously wetting the marking during measurement with the retroreflectometer (see Fig 1).

Note 1—Test Method E 2177 may be used to describe the performance of pavement markings in conditions of wetness after a period of rain.

1.3 This test method specifies the use of portable or mobile reflectometers that can measure pavement markings per Test Method E 1710. The entrance and observation angles required of the retroreflectometer in this test method are commonly referred to as "30 meter geometry."

1.4 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.

1.5 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.