Abstract
High index of refraction (1.65+) glass reads were field tested to determine if the increased cost of these beads could be justified on the basis of increased light reflectivity during the life of a pavement marking paint line. During the field test, measurements were made on these beads as well as the regular beads used by the state. As a result of photometer readings and bead counts in established test areas on asphaltic and Portland cement concrete pavements the following conclusions were drawn: Although the high index of refraction beads initially provided greater reflectance on Portland cement concrete pavement, after about eight weeks the reflectance had declined to a point where it was difficult.