Title: Essays on Transportation
Description: This dissertation provides three examples of how considering interactions across transport modes as well as land use systems is important for addressing the biggest challenges in sustainable development, particularly climate change and growing inequality. In the first essay, I explore path dependency in urban form for U.S. cities built around rail transit prior to the automobile. I find that these cities continue to be denser and have lower per capita transportation emissions than cities that came of age after the automobile. I estimate the size of the effect and how long it lasts. The built environment is durable, and urban infrastructure is costly to alter post-construction, so land use and transport decisions made early in a city’s history can have a lasting environmental impact. The second essay exploits a natural experiment to quantify the impact of bikesharing on bus transit ridership in New York City. This work demonstrates one way in which shared modes impact pre-existing public transit systems, which is particularly important as these systems are expanding and operating outside of traditional public agencies.

The way these modes work together determines the overall quality of the transport network. The third essay discusses the concept of accessibility and how accessibility measures can be used in the case of Nairobi to explore the dynamics of social exclusion across modes, residential location, and income. This dissertation provides three examples of how sustainability goals may fall short if transportation is not viewed as a multimodal system that interacts with and shapes urban form.