1. Graduate Research Assistant, School of Civil Engineering and Environmental Science, Univ. of Oklahoma, Norman, OK.
2. Asphalt Lab Manager, School of Civil Engineering and Environmental Science, Univ. of Oklahoma, Norman, OK.
3. Associate Research Engineer, Texas Transportation Institute, Texas A&M Univ., Bryan, TX.
4. Postdoctoral Research Associate, School of Civil Engineering and Environmental Science, Univ. of Oklahoma, Norman, OK.
5. David Ross Boyd Professor and Aaron Alexander Professor of Civil Engineering, Alumni Chair Professor of Petroleum and Geological Engineering, and Director, Southern Plains Transportation Center, Univ. of Oklahoma, Norman, OK.