1. Postdoctoral Research Scholar, Dept. of Civil and Environmental Engineering, Public Policy Center, Univ. of Iowa, 4117 Seamans Center, Iowa City, IA 52242-1527.
2. Associate Professor, Dept. of Civil and Environmental Engineering, Public Policy Center, Univ. of Iowa, 4117 Seamans Center, Iowa City, IA 52242-1527.
3. Assistant Director, National Center for Asphalt Technology, 277 Technology Pkwy, Auburn, AL 36830.