Experimental pavement delineation treatments

In 1975, 43 test sections of various delineation treatments were installed in an attempt to develop treatments with better visibility and durability than the color-contrast and synthetic-binder-concrete then used in New York State to delineate shoulders and medians adjacent to asphalt pavements. Materials evaluated were polysulfide and coal-tar epoxies, one- and two-component polyesters, portland cement, acrylic paints, modified-alkyd traffic paint, preformed plastic tape, and thermoplastic markings. Neat applications, sand mortars, and surface treatments were installed in several geometric patterns including cross-hatches, solid median treatments, and various widths of edge lines. Although several materials provided good daytime visibility and durability, most did not provide good night and wet-weather visibility. Thermoplastic pavement markings generally performed very well, providing good visibility under adverse viewing conditions for at least 4 years. Thermoplastic 4-in. wide edge lines appear to provide adequate visibility for most conditions. Wider lines or cross-hatching provide greater visibility where increased emphasis of the shoulder or median is desirable. (FHWA)