The "human" factor in the verification of the optical performances of materials for road marking with post-spraying

Safety is a priority for all management authorities of road networks. The factors that act together to reach high safety performance standards are the correct design of the axis geometry, the maintenance of functional levels of the pavement surface, the organization of adequate systems aimed at reducing accidents. Another safety factor is represented by the road marking. Basic requisites for a correct perception of the information supplied by the road marking are recognizability, visibility and readability, especially when driving conditions are unfavorable. In Italy, the test standard for verification of the performances of road marking is European regulation UNI EN 1436:2004, in which the testing methods of the functional parameters characteristic of the marking material are specified (Qd, RL, β chromaticity coordinates x and y, SRT). However, nothing is specified about the criteria which are necessary to guarantee the representativity, reproducibility and stability of the values obtained. This paper reports the results of a series of trials aimed at the definition of a new standard for testing horizontal road marking materials, which also takes into account the road user’s awareness and perception of the road space as a function of the category of road and speed of travel.