Precise life cycle models of service life of pavement markings are essential for a cost efficient pavement marking management system. This study is conducted in an effort to develop an analysis procedure for typical pavement marking retroreflectivity inspection data. The National Transportation Product Evaluation Program retroreflectivity inspection data collected on water based paints in 2002 on a Pennsylvania test deck was used in this study. The retroreflectivity inspection data was considered as interval level duration data and a Weibull analysis was performed. The results of the analysis indicated that the water based paints have shape and scale parameters of 1.42 (plus/minus 0.05), and 601.67 (plus/minus 17.73) days respectively for skipline areas and 2.38 (plus/minus 0.08) and 227.41(plus/minus 4.48) respectively for left wheel path areas. The study also found that the probability of two-year water based paints lasting above 100 mcd/sq.m/lux is zero to twenty seven percent. The lower limit corresponds to the left wheelpath and the upper limit corresponds to the skipline area. Moreover, the left wheelpath markings failed to stay above 100 mcd/sq.m/lux after approximately a year, while skip line markings could potentially maintain 100 mcd/sq.m/lux ratings or higher for over one thousand days. Furthermore, it was found that white markings last longer than yellow markings for the same exposure. Finally, it is to be noted that this study comprises data from a single site in Pennsylvania. An in-depth multi-site analysis that includes time and space variations is recommended prior to adoption of this method for minimum pavement marking visibility standard assessment.
Abstract