Date of Award

January 2017

Document Type


Degree Name

Master of Science (MS)


Mechanical Engineering

First Advisor

Cai Xia Yang


There are a variety of transit bus sizes and types that are suitable for different types of cities, services, and operations. The size of a bus has a direct effect on the operating costs due to fuel consumption. Also, selecting bus size properly is very important for correct functioning and the quality and service level of public transportation. A decision on selecting bus size, fuel type and model year can only be made after considering the demand for each of the service routes on the system, fuel cost, and emission level. It is necessary to provide engineering resources to the local transit service so that they can assign a right size and fuel type of bus to a specific route from the existing bus fleet. Accurate evaluation of fuel consumption is best assessed by comparative testing over relevant drive cycles. In this thesis, a computational model is developed to compare the fuel economy of city transit buses fueled by gasoline and diesel engines considering each bus service route, passenger load variation, and fuel type and bus size. We further explore the potential advantages of each model year and size of the bus for a specific route. Using this automatic calculation process, Transit agencies can develop and design future enhancement of transit services, improve operation efficiency, and environmental benefits of adding additional services with limited funding. This thesis would also be useful to examine the accuracy of projected operating costs and to support decision making on bus purchasing.