Design, construction, and maintenance of Open Graded Asphalts Friction Courses

Open-graded asphalt friction course (OGFC) is an open-graded Hot Mix Asphalt (HMA) mixture with interconnecting voids that provides improved surface drainage during rainfall. The rainwater drains vertically through the OGFC to an impermeable underlying layer and then laterally to the daylighted edge of the OGFC. In addition to minimizing hydroplaning potential during rainfall and providing improved friction values on wet pavements, the OGFC offers the following advantages compared to other dense-graded surfaces: (a) reduced vehicle splash and spray behind vehicles, (b) enhanced visibility of pavement markings, (c) reduced nighttime surface glare in wet weather, and (d) reduced tire-pavement noise.