ScienceDaily (Oct. 6, 2010) — Iowa State University's Christopher Williams was just trying to see if adding bio-oil to asphalt would improve the hot- and cold-weather performance of pavements. What he found was a possible green replacement for asphalt derived from petroleum. That finding will move from Williams' laboratory at the Institute for Transportation's Asphalt Materials and Pavements Program at Iowa State to a demonstration project this fall. The project will pave part of a Des Moines bicycle trail with an asphalt mixture containing what is now known as Bioasphalt.
http://www.sciencedaily.com/releases/2010/10/101006145049.htm