1. Professor, School of Transportation Science and Engineering, Beihang Univ., Beijing 100191, China.
2. Professor, Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji Univ., Shanghai 201804, China.
3. Associate Professor, Dept. of Civil Engineering, Shanghai Univ., Shanghai 200444, China; Associate Professor, Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji Univ., Shanghai 201804, China (corresponding author).