The effect of brightness of illuminated streets, i.e., the level and the uniformity of luminous density can be calculated if the lighting properties of road surfaces are known. The quality of street lighting does not only depend on the conditions of luminous density of the driveway, but above all on the contrasts of brightness between an obstacle and its vicinity. Various influences render good seeing possible or difficult. Many a problem is left to be solved. In order to be able to recommend the best possible street lighting in spite of all these difficulties, a test road for lighting purposes has been built at Traunreut (Bavaria) where nearly every kind of lighting may be tested with regard to quality and economy. The German standard DIN 5044 will be revised. The new edition will be based on an international draft (International Recommendations for Street Lighting) which was discussed for the first time in June 1963 at the Vienna meeting of the International Commission on Illumination (CIE). (A)
Abstract