1. School of Transportation Engineering, Shandong Provincial Key Laboratory of Road and Traffic Engineering in Colleges and Universities, Shandong Jianzhu University, No. 1000 Fenming Rd., Jinan, Shandong, PR China (Corresponding author), e-mail: zhaopinhui08@163.com, https://orcid.org/0000-0002-8252-6967
2. School of Transportation Engineering, Shandong Provincial Key Laboratory of Road and Traffic Engineering in Colleges and Universities, Shandong Jianzhu University, No. 1000 Fenming Rd., Jinan, Shandong, PR China
3. School of Transportation Engineering, Shandong Provincial Key Laboratory of Road and Traffic Engineering in Colleges and Universities, Shandong Jianzhu University, No. 1000 Fenming Rd., Jinan, Shandong, PR China (Corresponding author), e-mail: renruibochina@126.com