Development of the new code of practice for traffic routes

Abstract

A new code of practice for the lighting of traffic routes, based on the CIE recommendations for luminance design, is about to be introduced. This paper explains the way in which CIE recommendations have been applied to achieve a system which is simple in everyday use. Design tables, computed by manufacturers for their individual luminaires, enable spacing to be calculated for given performance criteria. Appropriate maintenance factors are derived. Linear interpolation in the computer program for establishing the design table is shown to be accurate enough, and an exchange of data between manufacturers shows very good agreement between the results from different computers. The use of threshold increment, rather than intensity restrictions to control glare is explained, as is the use of iso-luminance templates to ensure adequate uniformity round bends and the concept of effective width in dealing with lantern overhang.