1. Graduate Research Assistant, Zachry Dept. of Civil Engineering, Texas A&M Univ., 3136 TAMU, College Station, TX 77843.
2. Assistant Transportation Researcher, Texas Transportation Institute, 3136 TAMU, College Station, TX 77843.
3. Senior Research Engineer, Texas Transportation Institute, 3136 TAMU, College Station, TX 77843.
4. Associated Professor, Zachry Dept. of Civil Engineering, Texas A&M Univ., 3136 TAMU, College Station, TX 77843 (corresponding author).
5. Division Head, Texas Transportation Institute, 3136 TAMU, College Station, TX 77843.