1. Associate Professor, College of Transport and Communications, Shanghai Maritime Univ., 1550 Haigang Ave., Shanghai 201306, China.
2. Professor, Dept. of Civil Engineering and Environment, Univ. of Wisconsin–Milwaukee, P.O. Box 784, Milwaukee, WI 53201 (corresponding author).
3. Associate Professor, College of Urban Railway Transportation, Shanghai Univ. of Engineering Science, Longteng Rd., Shanghai 201620, China.
4. Professor, College of Transport and Communications, Shanghai Maritime Univ., 1550 Haigang Ave., Shanghai 201306, China.