1. Professor, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, 3106 NCEL 205 N. Mathews Ave., Urbana, IL 61801.
2. Postdoctoral Researcher, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, 3129a NCEL 205 N. Mathews Ave., Urbana, IL 61801.
3. Principal Engineer, Association of American Railroads, Transportation Technology Center, Inc., P.O. Box 11130, 55500 DOT Rd., Pueblo, CO 81001.
4. Engineer, Association of American Railroads, Transportation Technology Center, Inc., P.O. Box 11130, 55500 DOT Rd., Pueblo, CO 81001.