1. Assistant Professor, Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji Univ., 4800 Cao’an Rd., Shanghai, People’s Republic of China.
2. Assistant Professor, Dept. of Civil Engineering and Mechanics, Univ. of Wisconsin at Milwaukee, P.O. Box 784, Milwaukee, WI 53201-0784.
3. Professor, Key Laboratory of Road and Traffic Engineering of the Ministry of Education, Tongji Univ., 4800 Cao’an Rd., Shanghai, People’s Republic of China.