1. Research Assistant, Dept. of Civil, Construction, and Environmental Engineering, Iowa State Univ., 394 Town Engineering Bldg., Ames, IA 50011 (corresponding author).
2. Professor, Dept. of Civil, Construction and Environmental Engineering, Iowa State Univ., 490 Town Engineering Bldg., Ames, IA 50011.
3. Associate Professor, Dept. of Statistics, Iowa State Univ., 2417 Snedecor Bldg., Ames, IA 50011.
4. Assistant Professor, Dept. of Civil, Construction and Environmental Engineering, Iowa State Univ., 474 Town Engineering Bldg., Ames, IA 50011.
5. Associate Professor, Institute for Transportation, Iowa State Univ., Ames, IA 50011.
6. Bituminous Engineer, Office of Materials, Iowa Dept. of Transportation, Ames, IA 50011.
7. Postdoctoral Researcher, Dept. of Civil, Construction and Environmental Engineering, Iowa State Univ., 403 Town Engineering Bldg., Ames, IA 50011.