1. Assistant Professor, Beijing Key Laboratory of Traffic Engineering and College of Metropolitan Transportation, Beijing Univ. of Technology, Chaoyang District, Beijing 100124, China (corresponding author).
2. Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Wisconsin-Platteville, 137 Ottensman Hall, 1 University Plaza, Platteville, WI 53818.
3. Research Engineer, National Engineering Research Center of Road Maintenance Technologies and RoadMainT Co. Ltd., Bldg. No. 7, Block 9, Dijin Rd., Haidian District, Beijing 100095, China.
4. Professor and Gilbert, Cooper, W&W Steel Chair, School of Civil and Environmental Engineering, Oklahoma State Univ., Stillwater, OK 74074.