Patent attributes
An improved road marker with a one piece shell and recesses containing elongated members with an undercut relief is provided. The road marker contains a retroreflective lens and a bottom surface with a plurality of the recesses protruding into the shell. The cross section of the recesses can be in the shape of a circle, ellipse, triangle or any shaped polygon, and said cross section can vary as a function of the depth of the recess into the shell and the location of said recess on the bottom surface. The cross section of the elongated member in an axial direction can be in the shape of a circle, ellipse, triangle or any shaped polygon. The undercut relief can be in the form of threads, ridges or any type of indentation into the elongated member that provides a rough surface. When the elongated member is permanently attached to the road marker shell, the undercut relief thereon affords increased adherence between the road marker shell and any type of glue or adhesive used to attach the road marker to a road surface.