Dr. Butt is a Project Scientist and Sustainability Subject Project Manager working for the Pavement Research Center at University of California. Berkeley/Davis. He serves as a member of Center of Road2Science at KTH-Sweden, and is the reviewer of number of journals that include Journal of Cleaner Production, International Journal of LCA, IJPRT, Resources, Conservation and Recycling and others. Doing research and teaching are his passions.