1. Graduate Research Assistant, Dept. of Civil, Construction, and Environmental Engineering, Iowa State Univ., Ames, IA.
2. Pitt-Des Moines, Inc.; Endowed Professor of CCEE, ISU Site Director of FAA Partnership to Enhance General Aviation Safety, Accessibility and Sustainability (PEGASAS) Center of Excellence (COE) on General Aviation, and Director of Program for Sustainable Pavement Engineering and Research (PROSPER), CCEE, Iowa State Univ., Ames, IA.
3. Assoicate Director of PROSPER and Research Scientist of Institute for Transportation, Iowa State Univ., Ames, IA.