Public transit systems are often accepted as energy and environmental improvements to automobile travel, however, few life cycle assessments exist to understand the effects of implementation of transit policy decisions. To better inform decision-makers, this project evaluates the decision to construct and operate public transportation systems and the expected energy and environmental benefits over continued automobile use. The public transit systems are selected based on screening criteria. Initial screening included advanced implementation (5 to 10 years so change in ridership could be observed), similar geographic regions to ensure consistency of analysis parameters, common transit agencies or authorities to ensure a consistent management culture, and modes reflecting large infrastructure investments to provide an opportunity for robust life cycle assessment of large impact components. An in-depth screening process including consideration of data availability, project age, energy consumption, infrastructure information, access and egress information, and socio-demographic characteristics was used as the second filter. The results of this selection process led to Los Angeles Metro’s Orange and Gold lines.

In this study, the life cycle assessment framework is used to evaluate energy inputs and emissions of greenhouse gases, particulate matter (10 and 2.5 microns), sulfur dioxide, nitrogen oxides, volatile organic compounds, and carbon monoxide. For the Orange line, Gold line, and competing automobile trip, an analysis system boundary that includes vehicle, infrastructure, and energy production components is specified. Life cycle energy use and emissions inventories are developed for each mode considering direct (vehicle operation), ancillary (non-vehicle operation including vehicle maintenance, infrastructure construction, infrastructure operation, etc.), and supply chain processes and services. In addition to greenhouse gas emissions, the inventories are linked to their potential for respiratory impacts and smog formation, and the time it takes to payback in the lifetime of each transit system.

Results show that for energy use and greenhouse gas emissions, the inclusion of life cycle components increases the footprint between 42% and 91% from vehicle propulsion exclusively. Conventional air emissions show much more dramatic increases highlighting the effectiveness of “tailpipe” environmental policy. Within the life cycle, vehicle operation is often small compared to other components. Particulate matter emissions increase between 270% and 5400%. Sulfur dioxide emissions increase by several orders of magnitude for the on road modes due to electricity use throughout the life cycle. NOx emissions increase between 31% and 760% due to supply chain truck and rail transport. VOC emissions increase due to infrastructure material production and placement by 420% and 1500%. CO emissions increase by between 20% and 320%. The dominating contributions from life cycle components show that the decision to build an infrastructure and operate a transportation mode in Los Angeles has impacts far outside of the city and region. Life cycle results are initially compared at each system’s average occupancy and a breakeven analysis is performed to compare the range at which modes are energy and environmentally competitive.

The results show that including a broad suite of energy and environmental indicators produces potential tradeoffs that are critical to decision makers. While the Orange and Gold line require less energy and produce fewer greenhouse gas emissions per passenger mile traveled than the automobile, this ordering is not necessarily the case for the conventional air emissions. It is possible that a policy that focuses on one pollutant may increase another, highlighting the need for a broad set of indicators and life cycle thinking when making transportation infrastructure decisions.

Urban green space is purported to offset greenhouse‐gas (GHG) emissions, remove air and water pollutants, cool local climate, and improve public health. To use these services, municipalities have focused efforts on designing and implementing ecosystem‐services‐based “green infrastructure” in urban environments. In some cases the environmental benefits of this infrastructure have been well documented, but they are often unclear, unquantified, and/or outweighed by potential costs. Quantifying biogeochemical processes in urban green infrastructure can improve our understanding of urban ecosystem services and disservices (negative or unintended consequences) resulting from designed urban green spaces. Here we propose a framework to integrate biogeochemical processes into designing, implementing, and evaluating the net effectiveness of green infrastructure, and provide examples for GHG mitigation, stormwater runoff mitigation, and improvements in air quality and health.

In 1974, with a relatively young and fast-growing city in front of them, the City Council of Phoenix, Arizona charged the Phoenix Planning Commission with studying potential plans for urban form. Through the help of over 200 citizens over the next eight months, the village concept was born. Characterized by an emphasis on community-level planning, unique neighborhood character, and citizen input, the village concept plan provides an compelling lens into decentralized planning. In 1979, the Village Concept, as part of the “Phoenix Concept Plan 2000,” was officially adopted by the Phoenix City Council and has remained a component of the city’s long-range planning ever since. Each village features a core of dense commercial and residential activity, with a surrounding periphery featuring varied densities and land usage. There were nine original villages outlined in 1979. As of today, there are 15 villages. Each village has a Village Planning Committee (VPC) made up of 15 to 21 citizens, each being appointed to the committee by the Phoenix Mayor and City Council. This exploratory study was born out of an interest in the Village Planning Committees and a desire to understand their function as a mechanism for citizen participation in urban planning and urban governance. Similarly, with the rapid onset of the automobile and freeway expansion in the decades after WWII, once-insolated communities in the Valley have become connected to each other in a way that raises questions about how to maintain neighborhood’s unique character while promoting sustainable growth and expansion of the city. Phoenix’s Urban Village Model attempts to answer those questions. The efficacy of the model can be considered from two perspectives––how does it aid in making land use decisions, and how does it promote citizen participation? While there is an extensive body of literature on neighborhood councils in the United States and plentiful analysis of the merits of such models as participatory mechanisms and devices of urban planning, there is a lack of discussion of Phoenix’s Urban Village Model. This thesis aims to include Phoenix in this growing body of work.

Much of modern urban planning in the United States is concerned with making cities more walkable. However, this is occurring as the urban landscape of the U.S. is altered radically by changes in crime patterns after the summer of 2020. This paper seeks to find out what the relationship is between walkability and crime in major U.S. cities after 2020. Using multiple linear regressions at the city and neighborhood scale, walkability is found to be a significant, positive predictor of 2019 violent crime rate, 2020 violent crime rate, 2020 property crime rate, and 2020 total crime rate at the city level. It was found to be a positive, but not significant predictor at the neighborhood level. Walkability has no protective influence against crime/rising crime, and it appears that as crime gets worse it tends to get worse in the cities that are more walkable, but other variables such as African American population are better determinants of crime. Urban planners should seek to increase walkability while also finding a way to mitigate potential exposure to crime.