A study conducted by the Texas Department of Transportation found that up to 90% of pollutants in the highway were reduced by using open-graded friction courses (OGFCs) compared to conventional pavements. OGFCs surfaces is a term that means precipitation drains through the surface layer of the asphalt to an underlying layer and finally to the edge of the pavement. These types of asphalt pavements improve the quality of runoff from rainstorms and pollutants that can collect in the roadway. Added benefits from OGFCs include reduced noise from vehicles driving on the asphalt and minimized splashing from vehicles passing over wet roads.
