1. School of Economics, Hainan University, Haikou, Hainan, China
2. Key Laboratory of Road and Traffic Engineering of Ministry of Education, Tongji University, Shanghai, China
3. Department of Civil, Architectural and Environmental Engineering, Austin, Texas, United States
4. School of Civil and Environmental Engineering, University of New South Wales, Sydney, New South Wales, Australia
5. College of Civil Engineering and Architecture Zhejiang University, Hangzhou, Zhejiang, China