1. Assistant Professor, Dept. of Civil and Environmental Engineering, Seoul National Univ., 35-403 Gwanak-ro, Gwanak-ku, Seoul, Korea 151-744 (corresponding author).
2. Assistant Manager, Samsung Heavy Industries, 24th Fl. Samsung Life Insurance Seocho Tower, 1321-15 Seocho-2 dong, Seocho-gu, Seoul 137-857, Korea.
3. District Pavement Engineer, Texas Dept. of Transportation, Austin District, 7901 N. IH 35, Austin, TX 78753.
4. Associate Professor, Civil, Architectural, and Environmental Engineering Dept.–TRAN, Univ. of Texas, 1 Univ. Station C1761, Austin, TX 78712.
5. Research Engineer, Center for Transportation Research, Univ. of Texas, 1616 Guadalupe St., Suite 4.202, Austin, TX 78701.