1. College of Transportation Engineering, Tongji University, Shanghai 201804, China
2. Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji University, Shanghai 201804, China
3. College of Higher Technical, Shanghai Maritime University, Shanghai 201306, China
4. Shanghai Key Laboratory of Rail Infrastructure Durability and System Safety, Shanghai 201804, China
5. Department of Urban Management, Kyoto University, Kyoto 615-8540, Japan
6. Department of Civil and Environmental Engineering, University of Wisconsin-Milwaukee, PO Box 784, Milwaukee, WI 53211, USA