1. School of Transportation and Logistics, Southwest Jiaotong University, Chengdu, Sichuan 611756, China
2. Chongqing Jiaotong University, Chongqing Key Laboratory of Traffic & Transportation, Chongqing 400074, China
3. Office of Science Research & Development, Southwest Jiaotong University, Chengdu, Sichuan 611756, China