Technical specifications
page 68
last update: 30.07.2014
18. Graphical illustration of the measuring principles
18.1
Night visibility R
L
RL is the coefficient of retroreflected luminance (night visibility) of of road markings. The
observation angle of 2.29° corresponds to the viewing distance of a vehicle driver of 30 m under
normal conditions. The illumination angle is 1.24°.
18.2
Different illustration of R
L
The angle definitions above are valid for EN 1436. It is important to understand that EN 1436
and ASTM E1710 use different illustration of the same angles.
18.3
Day visibility Qd
Qd is the luminance coefficient under diffuse illumination (day visibility) of road markings. The
observation angle of 2.29° corresponds to the viewing distance of a vehicle driver of 30 m under
normal conditions. EN 1436 and ASTM E2302 use the same angle definitions.