This report was prepared to provide the results of evaluations conducted upon twenty-six roadways where rumble strips were installed experimentally in Louisiana between August 1982 and September 1984. Situated randomly throughout Louisiana, construction of these coarse-textured, exposed sandstone aggregate rumble strips was accomplished by district maintenance forces using conventional asphalt distributing equipment. The purpose of this project was to develop a supplement to typical traffic control devices, such as signs or signalization, where a substantial reduction in speed is required to divert driver inattentiveness towards a potentially hazardous intersection or situation. It was hoped that the audible and tactile stimuli provided by the designated intermittent pattern of the coarse-textured, exposed sandstone aggregate rumble strips would increase driver reaction time, thereby creating the reduction in speed necessary to reinforce or augment standard visual traffic control devices. This report addresses installation techniques/problems, relative aggregate durability, aggregate loss determinations, possible rejuvenation procedures and analyzes historical accident statistics prior to and after installation