Abstract
The photometric properties of different types of raised pavement markers have been determined by exposing them to traffic and measuring the coefficient of luminous intensity after various periods up to two years. After two years, markers with a plastic shell had lost at least 99 per cent of their reflectivity, while glass lens markers had lost 96 per cent. An analysis of the results indicates that the photometric requirements of AS1906 part 3 need revision, and that such requirements should be based on initial CIL values rather than on measurements done after eight weeks exposure to traffic. Plastic markers should have an initial CIL of approximately 500 mcd/lx, if they are to remain effective after two years (A).