1. Associate Professor, Beijing Key Laboratory of Traffic Engineering, Beijing Univ. of Technology, 100 Pingleyuan, Chaoyang District, Beijing 100124, China (corresponding author).
2. Master’s Student, Beijing Key Laboratory of Traffic Engineering, Beijing Univ. of Technology, 100 Pingleyuan, Chaoyang District, Beijing 100124, China.
3. Beijing Key Laboratory of Traffic Engineering, Beijing Univ. of Technology, 100 Pingleyuan, Chaoyang District, Beijing 100124, China.