1. Postdoctoral Researcher, Dept. of Civil, Environmental and Architectural Engineering, Univ. of Kansas, 2159A Learned Hall, 1530 West 15th St., Lawrence, KS 66045 (corresponding author).
2. Commonwealth Chair Professor of Transportation Engineering, Dept. of Civil Engineering, Univ. of Kentucky, 259 Raymond Building, Lexington, KY 40506.
3. Professor of Civil Engineering, Institute for Transportation, Dept. of Civil, Construction, and Environmental Engineering, Iowa State Univ., 2711 South Loop Dr., Suite 4700, Ames, IA 50010.