1. Professor, Dept. of Civil Engineering, Univ. of Kentucky, 265 Raymond Building, Lexington, KY 40506-0281 (corresponding author).
2. Professor, Dept. of Civil, Environmental, and Architectural Engineering, Univ. of Colorado at Boulder, Campus Box 428, Boulder, CO 80309-0428.
3. Kentucky Transportation Cabinet—District 2, 1840 N. Main St., Madisonville, KY 42431.
4. Graduate Research Assistant, Dept. of Civil Engineering, Univ. of Kentucky, 161 Raymond Building, Lexington, KY 40506-0281.