1. A. Abdelghany, College of Business, Embry-Riddle Aeronautical University, 600 South Clyde Morris Boulevard, Daytona Beach, FL 32114.
2. Department of Civil and Environmental Engineering, Southern Methodist University, P.O. Box 750340, Dallas, TX 75275-0340.
3. Transportation Center, Northwestern University, 215 Chambers Hall, 600 Foster Street, Evanston, IL 60208.
4. Civil Engineering Department, King Abdul-aziz University, P.O. Box 80204, Jeddah 21589, Saudi Arabia.