TRB 08-1311 Link-Based Emission Factors for Heavy-Duty Diesel Trucks Based on Real-World Data H. Christopher Frey, Ph.D. Professor, Department of Civil, Construction and Environmental Engineering North Carolina State University Campus Box 7908, Raleigh, NC 27695-7908 frey@ncsu.edu Nagui M. Rouphail, Ph.D. Director, Institute for Transportation Research and Education (ITRE) Professor, Department of Civil, Construction and Environmental Engineering North Carolina State University Centennial Campus Campus Box 8601, Raleigh, NC 27695-8601 rouphail@ncsu.edu Haibo Zhai Graduate Research Assistant Department of Civil, Construction and Environmental Engineering North Carolina State University Campus Box 7908, Raleigh, NC 27695-7908 hzhai2@ncsu.edu Text words 4841 plus 2500 words for 10 Tables/Figures= 7341 Words