1. Civil and Environmental Engineering, Villanova University, 800 E. Lancaster Ave., Villanova, Pennsylvania 19085, United States
2. RAND Corporation, 1776 Main Street, Santa Monica, California 90401 United States
3. Department of Civil and Environmental Engineering, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 United States
4. Department of Engineering and Public Policy, Carnegie Mellon University, 5000 Forbes Avenue, Pittsburgh, Pennsylvania 15213 United States