1. Ph.D. Student, Texas A&M Univ., 3136 TAMU College Station, TX-77843 (corresponding author).
2. Associate Professor, Zachry Dept. of Civil Engineering, Texas A&M Univ., 3136 TAMU College Station, TX-77843.
3. Senior Research Engineer, Texas Transportation Institute, 3135 TAMU College Station, TX 77843-3135.