1. College of Transportation Engineering, Chang’an University, Xi’an, Shaanxi, China
2. School of Transportation, Southeast University, Nanjing, Jiangsu, China
3. Department of Science, Technology and Informatization, China Academy of Railway Sciences Corporation Limited, Beijing, Hebei, China
4. Department of Engineering, Nottingham Trent University, Nottingham, UK
5. Department of Engineering, University of Cambridge, Cambridge, UK