VS - Lighting Systems - Lighting - 998542

5. The Lighting System: what is Light?

5.3.4.2. Reflectors luminance

The standard is to be able to see reflections between 60-160 m ahead at a height of 1.5 m. Asphalt reflectivity depends on surface conditions, dry, wet, icy, snowy, leaves, mud, etc. Due to asphalts relatively low reflectivity, markings are mandatory to highlight junctions, central reservation, road borders, etc.

Reflectors luminance occurs by reflecting light from another source.

Illuminance application in reflectors

4.3.4.4. Road marking luminance

The European standard, EN 1436, gives values for marking surface luminance.

It refers to: l Road marking colours (white or yellow). l Reflection during daylight or when under road lighting. l Reflection from vehicle headlamp illumination: - for dry road markings - for road markings in wet conditions, etc. Similar to the asphalt luminance coefficient, EN 1436 stipulates the visibility of the road markings as seen by a driver at a distance of 30 meters when illuminated by the vehicle’s headlamps.

5.3.4.3. Road luminance

The European standard, EN 13201, provides values for average road surface luminance. The luminance is a value of the luminous flux falling onto a road and the reflection characteristics of that surface. Road surface reflection characteristics depend on the nature of the surface (colour, aggregate type, binding agent and manufacturing method, texture, etc.) and physical state (wear, cleanliness and moisture of the surface). Luminance at any point depends on the emitted light angle and the observation angle. Asphalt tends to get lighter as it ages, due to oxidation and degradation of the binder, revealing the lighter-coloured aggregate.

Poor luminance with a worn making

Barely visible marking. Worn road markings lead to a poor luminance level.

16