Performance Evaluation of Green Pavement Markings for Bicycle Infrastructure

Abstract

Bicyclists depend on the visibility of the surrounding environment to maintain a safe travel path. Throughout the country, new types of bicycle infrastructure and pavement markings are being installed. This study used a new procedure to evaluate different pavement markings used in bike lanes. Three different paints were evaluated including green waterborne, green methyl methacrylate (MMA), and thermoplastic paint. The deterioration of these materials was tested under different conditions that simulated wear from motorized vehicles and street equipment. Surface polishing (i.e., repeated passing over the material) was examined under pneumatic tires, steel wheels, and steel scraper blades. Different characteristics were measured including durability, retroreflectivity, color changes, and surface friction of the test materials. The results demonstrated that the procedure used in this study was able to evaluate different materials in a short time compared to field evaluation which often can take years to complete. As expected, the retroreflectivity decreased with the number of polishing cycles. Overall, there was a significant decrease in percent retroreflectivity after 1,000 polishing cycles for all testing conditions before retroreflectivity eventually reached a terminal value. Based on the R2-values, a logarithmic model was suited to best describe the change in the retroreflectivity of markings with respect to loading cycles. The MMA paint experienced the lowest color loss even after 100,000 polishing cycles irrespective of the exposure and the testing conditions. It is believed that the small reduction in color is due to the presence of chemicals coupled with thicker paint of the MMA materials compared to waterborne materials. The durability results demonstrate that the waterborne markings peeled off the surface with increased polishing cycles. These findings will benefit transportation agencies, to predict the performance deterioration of various pavement markings for the bike lanes, and the proposal of new pavement making, while assisting in the schedule for marking maintenance projects.