1. Professor, School of Transportation, Southeast Univ., No. 2 Sipailou, Nanjing 210096, China; Professor and Chair, American Advanced Technology, LLC, Potomac, Catholic Univ. of America, 620 Michigan Ave., N.E., Washington, DC 20064.
2. Ph.D. Candidate, School of Transportation, Southeast Univ., No. 2 Sipailou, Nanjing 210096, China (corresponding author).