ASTM E2302-03a (R2016) PDF Download

The ASTM E2302-03a (R2016) standard provides guidelines for measuring the luminance coefficient of horizontal pavement markings and surfaces. The luminance coefficient, denoted as Qd, is a measure of the reflection of these materials in a specific viewing direction, under diffuse illumination conditions that approximate daylight illumination from the overcast sky and road lighting.

The quality and visibility of pavement markings are determined by the luminance coefficient, which is influenced by factors such as the materials used, age, and wear pattern. Higher levels of Qd correspond to higher levels of lightness under the same illumination and viewing conditions. Reflectivity of pavement markings may degrade with traffic wear, necessitating periodic measurement to ensure sufficient line visibility for drivers.

The standard specifies that measurements of Qd should be made using a reflectometer with a measurement geometry corresponding to a viewing distance of 30 m and an eye height of 1.2 m, as recommended by CEN (the European Committee for Standardization). It is the user's responsibility to employ an instrument with the specified co-viewing angle of 2.29°.

This test method is designed for field measurements of pavement markings and surfaces but can also be used to assess the performance of materials on sample panels before their placement in the field.