1. Graduate, Ministry of Education Key Laboratory for Urban Transportation Complex Systems Theory and Technology, Beijing Jiaotong Univ., Beijing, China 100044 (corresponding author).
2. Professor, State Key Laboratory of Rail Traffic Control and Safety, Beijing Jiaotong Univ., Beijing, China 100044.
3. Professor, Ministry of Education Key Laboratory for Urban Transportation Complex Systems Theory and Technology, Beijing Jiaotong Univ., Beijing, China 100044.