STUDY OF RETROREFLECTIVE AND COLORIMETRIC CHARACTERISTICS OF ROAD SIGNS DEPENDING ON THE TECHNOLOGY OF THEIR MANUFACTURE
Authors:   M.P. Shulgin State Road Research Institute State Enterprise – DerzhdorNDI SE, Kyiv, Ukraine, Shpin Denis , Kostrulova Tetiana ,   M.P. Shulgin State Road Research Institute State Enterprise – DerzhdorNDI SE, Kyiv, Ukraine, Khomiak Valeriia ,   M.P. Shulgin State Road Research Institute State Enterprise – DerzhdorNDI SE, Kyiv, Ukraine, Hostev Yurii ,   M.P. Shulgin State Road Research Institute State Enterprise – DerzhdorNDI SE, Kyiv, Ukraine
Published: March 2022

Introduction. Road signs form the framework of the driver's decision-making system in the process of vehicle driving, at the junction, separation and intersection of traffic and pedestrian flows. The most important in road signs are their luminance factor and retro reflectivity at nighttime; signs must have clear feedback. The more fully and clearly driver is informed about the conditions and needed modes of traffic,the more accurate and error-free are his actions. Problem statement. According to the analysis of accident rate statistics, most traffic accidents occur due to the inability of the driver to evaluate adequately the situation in conditions of insufficient visibility of road markings, signs and unsatisfactory lighting. According to researches, it has been determined, that improving the visibility of markings and signs can reduce traffic accidents by 10-30%. According to statistics, about 27% of traffic accidents occur due to driver inattention or loss of concentration. In Ukraine, such studies are almost non-existent, but according to traffic police data, in traffic accidents in the cities 50% of drivers consider also the cause of the collision tiredness or loss of concentration. An urgent task to eliminate the factors mentioned above is the use of high-quality informative road signs that will draw the driver's attention to the elements of the road situation (the presence of pedestrian crossings, possible complications of traffic conditions, trajectory of own vehicle move, etc.). For mounting quality signs, first of all, it is need to follow all the rules of technology of their production. Purpose. To study the retroreflective and colorimetric characteristics of road signs depending on the technology of their manufacture. Мaterials and methods. Laboratory studies for determination the influence of the technology of signs manufacturing on the specific luminous intensity factor, chromaticity coordinates, luminance factor. Results. The results of laboratory tests of road signs samples manufactured by different technologies for determination of specific luminous intensity factor, chromaticity coordinates, luminance factor are presented. Conclusions. Based on the results of studies, it can be concluded that the manufacturers of road signs need to work very carefully on the selection of inks for digital printing in order to achieve an image with high color endurance. Manufacturers are advised to have the needed devices to control the color at the stage of manufacture. Also, it can be noted that the specific luminous intensity factor of the road sign image of non-white characters made by digital printing is less important than the signs made by other technologies. Manufacturers need to draw attention to this and work over the possibility of achieving higher values of retro reflectivity. Keywords: road sign, lumina