1. Research Civil Engineer, U.S. Army Engineer Research and Development Center, 3909 Halls Ferry Road, Vicksburg, MS 39180 (corresponding author).
2. Assistant Director, National Center for Asphalt Technology, 277 Technology Parkway, Auburn, AL 36830.
3. Emeritus Professor, Industrial and Systems Engineering, 3301 Shelby Center, Auburn Univ., AL 36849.