1. Assistant Professor, Dept. of Civil and Environmental Engineering, Rutgers Univ., Piscataway, NJ 08854 (corresponding author).
2. Founder, Professor of Engineering, Director, Dept. of Civil and Environmental Engineering, Illinois Center for Transportation, Univ. of Illinois at Urbana-Champaign, Urbana, IL 61801.
3. Assistant Professor, Dept. of Civil and Environmental Engineering, Rice Univ., Houston, TX 77251.