1. Ph.D. Student, School of Transportation, Southeast Univ., Nanjing, Jiangsu 210096, P.R. China.
2. Professor, School of Transportation, Southeast Univ., Nanjing, Jiangsu 210096, P.R. China.
3. Professor, School of Transportation, Southeast Univ., Nanjing, Jiangsu 210096, P.R. China (corresponding author).
4. Master Student, School of Transportation, Southeast Univ., Nanjing, Jiangsu 210096, P.R. China.