[Libo, Zhou] Student, School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Wangjiali Road 960#, Changsha City, P.R.C,. E-mail:
[Qisen, Zhang] Professor, Changsha University of Science & Technology, Wangjiali Road 960#, Changsha City, P.R.C. E-mail:
[Yang, Xu] Senior Engineer, Hunan Traffic Design Institute, Wujialing Road, Changsha, P.R.C. E-mail:
[Hongxin, Guan] Associate Professor, School of Traffic and Transportation Engineering, Changsha University of Science & Technology, Wangjiali Road 960#, Changsha City, P.R.C. E-mail: