1. School of Civil and Transportation Engineering, Ningbo University of Technology, Ningbo 315211, China
2. Universität Duisburg-Essen, Duisburg 47057, Germany
3. Department of Transportation Engineering, Tongji University, Shanghai 201804, China
4. Intelligent Transport System (ITS) R & D Center, Shanghai Urban Construction Design and Research Institute (Group) Co., Ltd., Shanghai 201804, China
5. School of Traffic and Transportation, Lanzhou Jiaotong University, Lanzhou 730070, China