Abstract: A pavement marker has an unpotted upper shell and a lower base plate that together define a housing. A number of ribs are disposed in the housing interior oriented substantially perpendicular to the inner wall of the base plate. The upper shell has inclined end faces, an upper face, and is made of a plastic material having moderate to high flexural modulus and a high impact strength. The lower base plate has a planar inner wall and an opposed planar, pavement-engaging outer wall, and is made of a material having a Young's modulus of at least approximately 300,000 PSI (20.7.times.10.sup.8 Pascal). The ribs are formed unitarily with the inner wall of either the upper shell or the base plate, and extend upwardly from the inner wall of the base plate to the inner wall of the shell. A retroreflective lens is positioned on at least one of the first and second opposed side faces of the marker. The pavement marker resists delamination from a roadway surface when secured to the road with a soft adhesive.

Abstract: A fiber-reinforced raised pavement marker made of a composite material comprising an isotropic mixture of a polymeric material, reinforcing fibers and a filler material. The results of finite element analysis and composite technology have been combined to produce a pavement marker having high flexural strength and impact resistance without the need for an impact-resistant shell. Durable, high strength composite pavement markers are made by casting a homogenous mixture of chopped glass fibers and a filler material in a polymeric matrix. Placement of a retroreflective lens within the mold followed by pouring and curing the composite material results in a finished product upon release from the mold.