Standards of lighting necessary on main streets and highways.

This article is concerned with some of the different views which exist regarding the standard of lighting appropriate to the busier traffic routes. Public lighting codes usually deal with four aspects of the problem; I: the general level of the lighting, II: uniformity within the installation, III: limitations on glare, IV: visual guidance relating to the run of the road, etc. These four aspects are dealt with in separate sections of the article which also contains sections on the effect of the colour of the surface and the use of luminance (brightness) instead of illumination in modern codes.