1 Urban Transport Research Center, School of Traffic and Transportation Engineering, Central South University, Changsha 410075, China.
2 Department of Psychology, College of Arts and Sciences, University of Alabama at Birmingham, Birmingham, AL 35294, USA.
3 Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University, Changsha 410078, China.
4 Department of Epidemiology and Health Statistics, Xiangya School of Public Health, Central South University, Changsha 410078, China. huguoqing009@gmail.com.