1. Engineer IV, Mississippi Dept. of Transportation, Research Division, P. O. Box 1850, Jackson, MS 39215-1850; Adjunct Faculty Member, Mississippi State Univ., Starkville, MS (corresponding author).
2. Professor, Dept. of Civil and Environmental Engineering, Mississippi State Univ., P. O. Box 1798, Starkville, MS 39762.
3. Research Professor, Dept. of Civil and Environmental Engineering, Mississippi State Univ.. P. O. Box 9546, Starkville, MS 9762.