Development of Measures to Improve Field Performance of Retroreflective Raised Pavement Markers

Retroreflective raised pavement markers (RRPMs) are routinely used in Texas to supplement highway pavement markings. In recent years, problems of marker failure such as poor retention on pavements, physical damage, and loss of retroreflectivity are common. All marker models used in Texas meet the requirements set by American Society of Testing and Materials (ASTM) specifications. However, their performance varies significantly. The results from existing testing methods also do not correlate with field performance. It is therefore critical to identify or develop new lab testing methods that can accurately predict marker performance in the field. This report presents the research conducted over the three-year period to develop new lab tests that can predict marker field performance. Four field test decks were installed and monitored. Retroreflectivity and physical condition data were collected on six selected RRPM models at four deck locations that were selected based on traffic condition, pavement surface type, geographic and other environmental factors. Currently recommended ASTM tests, modified ASTM tests, and other new lab tests were conducted. Finite element modeling (FEM) of RRPMs under tire-marker impact and lab setting testing was also conducted. The marker performances from the test decks, under lab tests, and in simulation are compared. Based on the results of comparisons, a new lab test that best correlates with the field performance of the RRPMs is recommended.