1. Professor, Intelligent Transportation System Research Center, Southeast Univ., Nanjing, Jiangsu 210096, PR China.
2. Ph.D. Candidate, School of Transportation, Southeast Univ., Nanjing, Jiangsu 210096, PR China (corresponding author).
3. Associate Professor, Intelligent Transportation System Research Center, Southeast Univ., Nanjing, Jiangsu 210096, PR China.
4. Nanjing Railway Construction Investment Co., Ltd., Xinjiekou St., Xuanwu District, Nanjing, Jiangsu 210005, PR China.