Design Aspects - Road Lighting: Fundamentals, Technology and Application - page 188

Fig. 13.7 Example of good
visual guidance obtained by
the alignment of the
luminaires
Fig. 13.8 Luminaire siting
on curves and its
consequences for visual
guidance and ease of creating
luminance patterns on the
road
contribute more to the luminance of the road than do luminaires along its inside,
where the light is mainly reflected not by the road but by the road verge (illustrated
by the T-shaped luminance pattern of two individual luminaires in Fig. 13.8 top).
The systematic use of light sources of different colour can also contribute to the
quality of the visual guidance obtained. An example of this is the lighting of exits
from a motorway in a different colour than the lighting on the motorway itself.
Different light colours can also be used to guide road users through the road network
in and around a city by the consequent use of different colours for main through roads
and local roads. The effect can be strengthened by combining this with a consequent
difference in mounting height and or luminaire style. Of course, this requires master
planning of the road lighting in the whole area.