Ruixiao Sun

Date of Award

Fall 2022

Document Type

Open Access Dissertation


Civil and Environmental Engineering

First Advisor

Yuche Chen


It is critical to reduce road transportation emissions, as it is the major source contributing to greenhouse gas emissions (GHGs) and air pollution. However, the increasing travel demand due to the rise of population and economy makes the task challenging. Mathematically, road transportation emissions can be minimized in the manner of reducing total vehicle miles traveled (VMT) and lowering vehicle emission rate. Many strategies have been proven viable for achieving transportation sustainability. For example, the total VMT can be reduced by switching low-occupancy transportation modes (i.e., driving alone) to high-occupancy transportation modes (i.e., public transit, ridesharing). The development of alternative-fuel vehicles (i.e., hybrid vehicles and electric vehicles) provides the prospect of minimizing vehicle emission rates or achieving net zero emissions. These strategies are active in urban transit and high-occupancy vehicle systems. Many studies focused on the field of urban transit and high-occupancy vehicle systems. However, there are several challenges and scientific gaps related to sustainability in this field. For example, the lack of investigation of energy estimation models for hybrid buses that can support energy-oriented transit operations. The need to develop an environmental impact evaluation framework for assess the energy and environmental impact of ridesharing services with consideration of individual level (i.e., agent) behavior changes. An energy-saving and time efficient charging system for electric buses on complex transit networks is required to developed in order to promote the emerging of electric buses in transit usage.


© 2022, Ruixiao Sun