Enhancements to ConnDOT\u2019s Pavement Friction Testing Program

US Transportation Collection2011PDFResearch PaperHenault, John W.Connecticut. Department of Transportation. Division of ResearchConnecticut. Department of TransportationUnited States. Department of Transportation. Federal Highway AdministrationConnecticut. Department of TransportationConnecticutFriction testsPavementsSurface course (Pavements)FrictionSkid trailersSkiddingPavement friction testingSkid testingConnecticut Department of TransportationConnDOT, Locked-wheel friction testerCT-2243-F-10-4CT Study No. SPR-2243This report documents the work performed and results obtained for research conducted to enhance ConnDOT's pavement friction testing program. The program was enhanced with the purchase in 2005 of a new Dynatest 1295 Pavement Friction Tester. Upgrades from the previous tester included the addition of a high-speed laser to measure pavement macrotexture, and a global positioning system to track coordinates. A Circular Texture Meter was purchased in 2006 to compare to the high-speed laser. In 2007, the new friction tester was upgraded to a dual-sided system, enabling testing in either wheelpath. Speed gradients for various ConnDOT pavement surfaces were determined, the macrotexture of asphalt pavement designs used in Connecticut were characterized, the use of the International Friction Index was evaluated, and the effects of roadway geometry on friction measurements were studied. Deliverables include new and upgraded equipment, recommendations, tentative guidelines for evaluating friction at high wet accident sites in Connecticut, a procedure for handling friction test requests, and a draft policy statement.133