Design Aspects - Road Lighting: Fundamentals, Technology and Application - page 181

single-sided w < h

staggered w < 1,5 h

opposite w < 2,5 h

central w < 2 h

twin central w < h

Fig. 13.3 The five basic lighting arrangements

In residential areas with a non-linear street layout, far more flexible non-standard
arrangements may, of course, be used. The type of arrangement, together with the
width of the road, determine for an important part the mounting height, spacing,
overhang and inclination of the luminaires.

13.1.1 Effective Road Width

The amount of luminaire overhang (viz. the distance that the luminaire projects out
or is placed back from the kerb (Fig. 13.4 ) serves to determine the effective width of
the road and thereby the minimum mounting height required for the luminaires.
Inclining or tilting the luminaires up from the horizontal is done to increase the
road width covered with a given mounting height. But this measure is not very
effective. If the effective road width is large compared to the mounting height, tilting