The relationship between initial retroreflective luminous coefficient, thickness and retroreflection attenuation of thermoplastic markings

Abstract

This study aims to investigate the effect of thickness and initial retroreflective luminous coefficient (RL) on the retroreflection attenuation of thermoplastic road marking. The road marking with a thickness range of 2.5-3.7 mm were divided into six groups with a 0.2 mm interval to assess the relationship between the initial RL and the retroreflection attenuation. The settlement pattern of glass beads was also investigated for road markings with different thicknesses. Furthermore, the road markings with an initial RL range of 457-492 mcd·lx-1·m-2 and a thickness range of 2.46 ~ 3.42 mm were divided into four groups. The RL values at 7, 15, 30, 60 and 90 days were measured and compared to assess the impact of thickness and initial RL on retroreflection attenuation. It is concluded that the change of RL value is due to the change of glass bead embedment. When the thickness is 3.08 mm and the initial RL is 465.5 mcd·lx-1·m-2, there is a noticeable delay in the retroreflection attenuation.