Dow, the University of Missouri and the Missouri Department of Transportation are using single-use plastic waste as an alternative to stone, sand or gravel as an aggregate for asphalt. "In our work with Dow, we conducted accelerated laboratory testing to show that the waste plastic will not leach out of the asphalt, either via the presence of rainwater on the pavement or as a result of vehicles placing stress on the pavement surface," said Bill Buttlar of the University of Missouri.