Design Improvements of Retroreflective Raised Pavement Markers Based on Quantification of Their Physical Properties

Retroreflective raised pavement markers (RRPMs) are frequently used on roadways in many U.S. states to provide guidance to drivers as supplement to regular markings. Due to the large quantity of RRPMs required on a roadway network, their durability significantly impacts the annual cost of a transportation agency to maintain and replace them. Frequent structural damages of RRPMs, however, are often observed in the field, which lead to shorter-than-expected service lives. It is necessary to investigate the physical properties of current RRPM designs so as to find potential ways of design improvements for extending their service lives. This study focuses on mechanistic analysis of several popular RRPM designs for the impacts of design factors on their major failure modes. With inputs from literature review, questionnaire survey, and field observations, finite element analysis (FEA) models of the tire/RRPM/pavement system were built for the analysis. The FEA models were verified with field measurements of RRPM responses to wheel loads. An in-depth study was continued to optimize the geometric and material designs of RRPM. It is recommended to decrease the profile height and surface area or to increase the bottom area of RRPM to mitigate the mechanical damage. A life cycle cost analysis suggested a significant amount of cost saving from the recommended design changes.