1. School of Highway, Chang’an University, Middle-section of Nan-er Huan Rd., Xi’an, Shaanxi 710064, P. R. China (Corresponding author), e-mail: zhelu@chd.edu.cn, https://orcid.org/0000-0001-6877-9426
2. School of Highway, Chang’an University, Middle-section of Nan-er Huan Rd., Xi’an, Shaanxi 710064, P. R. China, https://orcid.org/0000-0001-9342-861X (Z.F.)
3. Jilin Provincial Transport Scientific Research Institute, 908 Jinhua St., Chaoyang District, Changchun, Jilin 130012, P. R. China
4. Shandong Transportation Service Center, Jinan, 29 Shungeng Rd., Shizhong District, Jinan, Shandong 250014, P. R. China
5. Highway Bureau of Shanxi Province, 71 Shifan St., Xiaodian District, Taiyuan, Shanxi 030006, P. R. China