1. Jiangsu Key Laboratory of Traffic and Transportation Security, Huaiyin Institute of Technology, Huaian 223003, China
2. School of Transportation, Southeast University, Nanjing 210096, China
3. Faculty of Management Engineering, Huaiyin Institute of Technology, Huaian 223003, China
4. Department of Civil and Environmental Engineering, The Pennsylvania State University, State College, PA 16802, USA