1. Director, Louisiana Transportation Research Center, 4101 Gourrier Ave., Baton Rouge, LA 70808.
2. Irma Louise Rush Stewart Distinguished Professor, Dept. of Civil and Environmental Engineering and Louisiana Transportation Research Center, Louisiana State Univ., 4101 Gourrier Ave., Baton Rouge, LA 70808 (corresponding author).
3. Associate Professor, Dept. of Civil and Environmental Engineering, Louisiana State Univ., PTF Hall, Room 3526C, Baton Rouge, LA 70803.