The results of a study directed toward increasing the retention time of raised pavement markers on asphalt concrete pavement are described. Retention time is believed to be largely limited by fatigue strength of the pavement surface. The kinematics of a tire striking a raised pavement marker were studied by high-speed photography to guide development of a laboratory apparatus that simulates pavement fatigue loading by a tire rolling over a marker. A laboratory investigation of the effect of adhesive type on fatigue strength of asphaltpavement was made. It was found that bituminous adhesive is distinctly superior to epoxy adhesive on new asphalt surfaces. The distinction between bituminous and epoxy adhesive is less pronounced on stiffer (seasoned) pavements. An instrumented pavement marker to record the number of tire hits was also developed during the study. The circuitry is described, and hit count data obtained with instrumented lane line markers are reported. These data, together with the laboratory fatigue data, permit prediction of retention time for a particular application. The paper concludes with an analysis of data from several adhesive test sections on state highways. Data from one test section show that it is possible to replace a missing marker with a new marker installed directly on the pavement failure spot instead ofalongside it. This paper appears in transportation research record no. 1230, Work-zone traffic control and tests of delineation material.
Abstract