1. Ph.D. Candidate, School of Qilu Transportation, Shandong Univ., 250002 Jinan, China.
2. Professor, School of Qilu Transportation, Shandong Univ., 250002 Jinan, China; formerly, School of Civil Engineering, Univ. of Leeds, LS2 9JT Leeds, UK (corresponding author). ORCID: .
3. Associate Professor, School of Qilu Transportation, Shandong Univ., 250002 Jinan, China.
4. Professor, School of Qilu Transportation, Shandong Univ., 250002 Jinan, China.