1. State Key Laboratory of Automotive Safety and Energy, Tsinghua University, Beijing 100084, China
2. Hunan Key Laboratory of Smart Roadway and Cooperative Vehicle-Infrastructure Systems, Changsha University of Science and Technology, Changsha, Hunan 410114, China
3. Key Laboratory of Safety Design and Reliability Technology for Engineering Vehicle, Changsha University of Science and Technology, Changsha, Hunan 410114, China
4. Department of Statistics, Columbia University in the City of New York, NY 10031, USA