1. Ph.D. Student, Dept. of Civil, Construction, and Environmental Engineering, Colorado State Univ., Fort Collins, CO 80523-1372.
2. George T. Abell Professor in Infrastructure, Dept. of Civil, Construction, and Environmental Engineering, Colorado State Univ., Fort Collins, CO 80523-1372 (corresponding author).
3. Associate Professor, Dept. of Civil and Environmental Engineering, Michigan Technological Univ., Houghton, MI 49931.