[1]Department of Engineering and Public Works City of Alpharetta GA 30009 USA;
[2]Department of Ciui;
Architectural and Environmental Engineering Illinois Institute of Technology Chicago IL 60616 USA;
[3]School of Highway Chang'an Uniuersity Xi'an 710064 China;
[4]Herbert S. Leuinson Transportation Consultant New Hauen CT 06492 USA;