1. Beijing Key Laboratory of Traffic Engineering, Beijing University of Technology, Beijing, China;
2. Key Laboratory of Road and Traffic Engineering of the Ministry of Education, College of Transportation Engineering, Tongji University, Shanghai, China;
3. Link Lab & Department of Engineering Systems and Environment, University of Virginia, Charlottesville, VA, USA;
4. Department of Civil, Environmental, and Geo-Engineering, University of Minnesota, Minneapolis, MN, USA