1. School of Transportation, Southeast Univ., No. 2, Southeast University Rd., Jiangning District, Nanjing 211189, China.
2. Associate Professor, Jiangsu Key Laboratory of Urban ITS, Jiangsu Collaborative Innovation Center of Modern Urban Traffic Technologies, School of Transportation, Southeast Univ., No. 2, Southeast University Rd., Jiangning District, Nanjing 211189, China.