1. Univ. of Illinois at Urbana-Champaign, Newmark Civil Engineering Laboratory, MC 250, Urbana, IL 61801; presently, 1572 Leyden St., Denver, CO 80220.
2. Associate Professor and Director of Railroad Engineering Program, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana-Champaign, Newmark Civil Engineering Laboratory, MC 250, Urbana, IL 61801.