Field characterisation of road surfaces reflection properties for several observation angles with a portable measuring device

It has been shown that the use of CIE standard r -tables, instead of actual reflection properties of stabilised pavements, frequently leads to non-compliance with EN 13201 standard, particularly in terms of uniformities. Furthermore, the conventional observation geometry of 1° does not represent the preferred observation geometries of different road users in urban areas. In this paper, we present the device COLUROUTE2 that can be used to measure the r -table of a road surface on site for observation angles between 1° and 10°. Our experimental campaigns carried out on 18 different pavements (with bituminous mixtures and cement concretes) confirm that the CIE road photometric indicators S 1, Q 0 and Q d generally decrease as the observation angle increases. Our results show that the assumption of equivalence of Q 0 and Q d measurements between 1° and 2.29° in the CIE 144 technical report is not always valid, but there are strong correlations between the different observation angles.