1. School of Traffic and Transportation Engineering, Changsha Univ. of Science and Technology, Changsha 410114, CN (Corresponding author), e-mail: zjhtamu@gmail.com
2. School of Traffic and Transportation Engineering, Changsha Univ. of Science and Technology, Changsha 410114, CN.
3. Jiangxi Ganyue Expressway Co. Ltd, Nanchang 330029, CN.