1. Graduate Research Assistant, Virginia Tech Transportation Institute, 3500 Transportation Research Bldg., Blacksburg, VA 24061. E-mail: edeleoni@vt.edu
2. Associate Professor, Virginia Tech, 3500 Transportation Research Bldg., Blacksburg, VA 24061. E-mail: flintsch@vtti.vt.edu
3. Senior Research Scientist, Virginia Transportation Research Council, 530 Edgemont Rd., Charlottesville, VA 22903. E-mail: Kevin.McGhee@VDOT.Virginia.gov