1. Research Assistant Professor, Center for Transportation Research, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, 309 Conference Center Bldg., Knoxville, TN 37996-4133.
2. Professor and CATSS Executive Director, Center for Advanced Transportation Systems Simulation, Univ. of Central Florida, Orlando, FL 32816-2450 (corresponding author).
3. Research Associate, Environmental Sciences Division, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831-6036.
4. Research Professor, Dept. of Civil and Environmental Engineering, Univ. of Tennessee, 62 Perkins Hall, Knoxville, TN 37996-2010.