1. Graduate Research Assistant, Texas A&M Transportation Institute, Texas A&M Univ. (TAMU) System, 3135 TAMU, College Station, TX 77843-3135 (corresponding author).
2. Associate Research Scientist, Texas A&M Transportation Institute, Texas A&M Univ. System, 3135 TAMU, College Station, TX 77843-3135.
3. Professor, Zachry Dept. of Civil Engineering, Texas A&M Univ., 3135 TAMU, College Station, TX 77843-3135.