1. Transport Studies Group, University of Westminster, 35 Marylebone Road, London NW1 5LS, United Kingdom
2. Center for Urban Transportation Research, College of Engineering, University of South Florida, 4202 East Fowler Avenue, CUT 100, Tampa, FL 33620
3. Department of Civil and Environmental Engineering, University of South Florida, ENB 118, 4202 East Fowler Avenue, Tampa, FL 33620-5350