Serviceable Pavement Marking Retroreflectivity Levels: Technical Report (0-5656-1)

This research addressed an array of issues related to measuring pavement markings retroreflectivity, factors related to pavement marking performance, subjective evaluation process, best practices for using mobile retroreflectometers, sampling pavement markings, and best practices for a Pavement Marking Management system. Test conducted to assess subjective evaluation showed inconsistency in subjective retroreflectivity evaluation when compared between different evaluations, marking color, and retroreflectivity levels. Sensitivity testing on several factors that could potentially affect mobile retroreflectometer readings showed that distance from which the measurements are taken and position across the measurement window seemed to have the most significant impact on the mobile retroreflectivity measurements. The evaluation factors of data acquisition, vehicle speed, and small changes in measurement geometry made no practical difference to the measurement. However, constant speed provided best results. Based on the sensitivity testing this report enlists some best practices for mobile retroreflectometer measurements. A methodology for combining mobile retroreflectivity data with pavement information and plotting a map, color coded based on pavement marking retroreflectivity level using GIS, are demonstrated in this project. This report also provides discussion on other best practices for sampling and Pavement Marking Management system.