Business School University of Shanghai for Science and Technology Shanghai 200093 China;
Zhejiang university urban and rural planning&design institute Hangzhou 310023 China;
Zhejiang university urban and rural planning&design institute Hangzhou 310023 China;
School of Computer&Communication Engineering Changsha University of Science&Technology Changsha 410004 China;
Highway transportation; traffic volume limit; emission control; carbon monoxide.;