Is grooving of pavements an effective way to provide skid resistance?
A study was made in California in 1968 and 1969 which shows that grooving on freeways reduced wet weather accidents by 85 percent. The grooves that were studied had been cut longitudinally by diamond blades. They were 0.095 inch wide,1/8 inch deep and spaced at 3/4 inch. It was concluded that the longitudinal cutting assisted drivers in maintaining directional control when pavements are wet. In recent years hundreds of miles of excessively worn concrete pavement in California have been restored to good skid resistance by grooving. Another 5.5 million square yards were grooved in 1972.