1. Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Missouri, E2503 Lafferre Hall, Columbia, MO 65211 (corresponding author).
2. Associate Professor, School of Civil Engineering, Purdue Univ., 550 Stadium Mall Drive, West Lafayette, IN 47907.
3. Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Missouri, E2509 Lafferre Hall, Columbia, MO 65211.
4. Professional Services Industries, Federal Highway Administration Turner-Fairbank Highway Research Center, McLean, VA 22101.