1. Professor, Changsha Univ. of Science and Technology; and Associate Professor, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, Knoxville, TN 37996 (corresponding author).
2. Research Associate, Louisiana Transportation Research Center, Baton Rouge, LA 70808.
3. Postdoctoral Research Associate, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, Knoxville, TN 37996.