1. Ph.D. Candidate, The Key Laboratory of Road and Traffic Engineering, Ministry of Education, Tongji Univ., Shanghai 201804, China (corresponding author).
2. Professor, The Key Laboratory of Road and Traffic Engineering, Ministry of Education, Tongji Univ., Shanghai 201804, China.
3. Ph.D. Candidate, Centre for Pavement and Transportation Technology, Dept. of Civil and Environmental Engineering, Univ. of Waterloo, Waterloo, ON, Canada N2L 3G1.
4. Senior Engineer, Gansu Province Transportation Planning, Survey & Design Institute, Yanbei Rd. 1689, Lanzhou 730000, China.