Skid resistance is the force developed when a tire that is prevented from rotating slides along the pavement surface. It is a function of the micro and macro texture of the pavement surface. An index value is assigned (skid score) based on measurements taken with a locked-wheel skid trailer towed behind a specially designed truck. The trailer administers a water spray to the pavement in front of the left tire. Smooth-treaded trailer tires are used. Testing is accomplished at 50 mph by locking the trailer’s left wheel at periodic intervals while a metered amount of water is sprayed on the pavement surface. Scores generally range from 10 to 40, with the higher number indicating greater skid resistance. These systems are scheduled through the Pavement Evaluation office (Pavement Preservation, MNT) at (512) 832-7210.