In 1997, Texas mixed discarded roofing shingles into two 1,000-foot Highway 31 test sections

Highway engineers in Texas have shown that discarded household roofing shingles can be recycled into durable road surfaces that perform as well as standard asphalt after years of heavy traffic. In 1997, the Texas Department of Transportation (TxDOT) built two 1,000-foot test sections along State Highway 31 in the Dallas District using hot mix asphalt containing processed shingle waste. Long-term monitoring showed that the recycled road surfaces performed as well as traditional asphalt control sections. The results helped lay the groundwork for state-wide rules allowing recycled asphalt shingles to be used in road construction. The trial was part of a wider research project documented by the Center for Multidisciplinary Research in Transportation at Texas Tech University. It was also covered in TxDOT report 9-1509-2, Road to Recycling: Findings and Recommendations, written by research supervisor Phillip T. Nash and project director Rebecca Davio.Testing post-consumer and factory wasteThe State Highway 31 trial tested two different sources of waste shingles to find out whether their origins or processing affected pavement performance. One 1,000-foot test section used five per cent po...