1. School of Engineering, Tibet University, Lhasa, Tibet, China
2. School of Transportation, Southeast University, Nanjing, Jiangsu, China
3. Jiangsu Key Laboratory of Urban ITS, Southeast University, Nanjing, Jiangsu, China
4. Research Center for Internet of Mobility, Southeast University, Nanjing, Jiangsu, China
5. Department of Civil and Environmental Engineering, University of Wisconsin–Madison, Madison, WI