1. Professor, Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji Univ., Shanghai 201804, China (corresponding author).
2. Graduate Research Assistant, Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji Univ., Shanghai 201804, China.
3. Professor, Dept. of Civil, Construction, and Environmental Engineering, Univ. of Alabama, Tuscaloosa, AL 35487.
4. Associate Professor, Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji Univ., Shanghai 201804, China.