Luminances and visibility in road lighting - conditions, measurements and analysis

......................................................................................................... 3 1 Table of contents ........................................................................................ 4 2 Introduction ............................................................................................... 5 2.1 Mesopic light levels ............................................................................. 6 2.2 The spectral sensitivity of the eye ......................................................... 6 2.3 The mesopic luminance region ............................................................. 6 2.4 S/P -ratio of light sources .................................................................... 7 3 Road and street lighting measurements ....................................................... 9 3.1 Methods for road lighting measurements .............................................. 9 3.2 Results of measurements ................................................................... 10 3.3 Luminance levels and adaptation luminance in driving situations ......... 11 4 Pedestrian visibility tests in the test room ................................................. 13 4.1 Experimental set-up .......................................................................... 13 4.2 Pedestrian visibility test 1 ................................................................. 14 4.3 Pedestrian visibility test 2 ................................................................. 16 4.4 Pedestrian visibility test 3 ................................................................ 17 4.5 Conclusions of pedestrian visibility tests ............................................. 19 5 Contrast threshold measurements ............................................................. 22 5.1 Experimental set-up .......................................................................... 22 5.2 Results and conclusions of contrast threshold measurements ............... 23 6 Conclusions .............................................................................................. 25 7 References ............................................................................................... 27