This study compares the modeled exhaust emissions for heavy-duty diesel vehicles of various weights traveling two different bi-directional routes through the Burlington, Vermont, area. The two routes are I- 89/I-189, between the junction at US-7 and Exit 16 in Colchester, and US-7, between the same two locations. Currently, heavy vehicles exceeding 80,000 pounds are prohibited from traveling on the analyzed section of interstate highway without permit due to federal regulations, and instead travel through the Burlington area along the designated US-7 truck route. For the analysis, real-world velocity, acceleration, and roadway grade data are used to model the pollutant emissions using the Comprehensive Modal Emissions Model to ascertain the differences in emissions, if any, between the interstate and US-7 routes. Results indicated that overall emissions inventories and per-mile emission rate were lower by up to about 50% for the I-89/I-189 routes compared to the US-7 routes. However, emissions of NOx were very similar between the counterpart routes, and in one case, the southbound interstate\u2019s NOx emissions were greater than US-7, by approximately 2-6% depending on vehicle weight. Lastly, there would be an overall savings in diesel fuel use up to approximately one gallon per truck traveling on I-89/I-189 compared to US-7
