1. Qinghai Provincial Highway Bureau, Xining, Qinghai, People’s Republic of China; School of Automotive and Traffic Engineering, Wuhan Univ. of Science and Technology, Wuhan, Hubei, People’s Republic of China.
2. Faculty of Architecture, Civil and Transportation Engineering, Beijing Univ. of Technology, Beijing, People’s Republic of China; Qinghai Provincial Highway Bureau, Xining, Qinghai, People’s Republic of China.
3. School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, People’s Republic of China (corresponding author).
4. School of Transportation Science and Engineering, Harbin Institute of Technology, Harbin, Heilongjiang, People’s Republic of China.
5. Institute of Railway Engineering, China Academy of Railway Sciences, Beijing, People’s Republic of China.