Date of Award

Spring 1-1-2017

Document Type


Degree Name

Master of Science (MS)

First Advisor

Shelly L. Miller

Second Advisor

Michael Hannigan

Third Advisor

Darin Toohey


This research examined the major pollutants produced by diesel-powered engines within the city of Boulder, Colorado: particulate matter, black carbon, and nitrogen oxides. Ozone was studied due to its secondary formation from nitrogen oxides. Summer and Winter measurements were taken next to the Boulder Downtown Bus Station, for one week in each season. It was not possible to estimate bus emissions due to variability in the number of vehicles and buses traveling in the study corridor.

Bicycle rides were carried out to capture fresh emissions on-road. Black carbon concentration peaked when chasing certain buses, while emissions from other buses were low. Passenger vehicle emissions were not reflected in the black carbon levels.

With the use of MOVES and R-Line, the impact of buses on the concentration of pollutants was analyzed. Results showed the fraction of NOx and PM that could be attributable to buses was between 24-40% and 16-45%, respectively.