1. Department of Civil Engineering, University of Texas at Tyler, RBS 1006, 3900 University Boulevard, Tyler, TX 75799.
2. Center for Transportation Research, University of Texas at Austin, 1 University Station, C1761, Austin, TX 78712.
3. Department of Civil, Architectural, and Environmental Engineering, University of Texas at Austin, 1 University Station, C1761, Austin, TX 78712.