1. Graduate Research Assistant, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana–Champaign, Urbana, IL 61801 (corresponding author).
2. Bliss Professor of Engineering, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana–Champaign, Urbana, IL 61801.
3. Research Assistant Professor, Dept. of Civil and Environmental Engineering, Univ. of Illinois at Urbana–Champaign, Urbana, IL 61801.
4. Specialist, Pavement Division, Danish Road Directorate, 27 Havnegade St., 1058 Copenhagen, Denmark.