Doctor of Philosophy with a Major in City and Regional Planning

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Publication Search Results

Now showing 1 - 10 of 53
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    Breaking Myths behind "Bikelash": Empirical analyses on the role of protected bike lanes on creating a sustainable, equitable, and safer transportation environment
    (Georgia Institute of Technology, 2023-12-10) Hwang, Uijeong
    While cycling is recognized as an eco-friendly alternative to carbon-emitting vehicles and a facilitator of physical activity, opposition to cyclists and bike lanes—termed “bikelash”—persists. This resistance stems from various concerns, ranging from the belief that bike lanes are underutilized and thus a waste of public space to fears that they may exacerbate traffic congestion or even contribute to urban gentrification. Through three detailed studies, this dissertation aims to provide empirical evidence challenging common perceptions and to reshape the narrative surrounding bike lanes. The first study investigates how bike lanes sway individuals' transportation choices, especially favoring non-automotive travel. It employs a novel approach by conducting a route-level analysis using origin-destination data from household travel surveys to simulate potential cycling routes. This study finds that bike lanes significantly encourage the use of walking, cycling, and public transit, thereby reducing car dependency. Notably, it demonstrates the potential of bike lanes to bridge mobility gaps in diverse socio-economic settings, even in underserved neighborhoods. The second study examines how the perception of streetscapes and different types of bike lanes interact to influence cycling behaviors. Utilizing computer vision to interpret perceptual attributes from crowdsourced street view images, the research reveals that the presence and type of bike lanes significantly influence cycling frequency, moderated by the visual perception of streetscape safety. Protected bike lanes are shown to be more effective in areas perceived as less safe, emphasizing their role in equitable transportation. The final paper delves into the safety impact of bike lanes, particularly focusing on near-miss incidents. It utilizes crowdsourced data to examine the risk of near misses in relation to street design and types of bike lanes. The findings indicate that protected bike lanes significantly reduce the risk of near misses, while striped lanes adjacent to street parking increase safety hazards. This challenges existing assumptions about bike lane safety and calls for a strategic shift towards protected bike lanes. This dissertation contributes to practical applications by providing critical empirical evidence to guide urban infrastructure planning and policymaking. The findings support a shift towards protected bike lanes, emphasizing their role in enhancing safety and increasing cycling frequency. The dissertation advocates for a holistic approach in urban transportation planning, promoting inclusive, sustainable, and safer urban environments.
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    Connectivity for whom and at what cost: contesting network infrastructure duality in urban planning
    (Georgia Institute of Technology, 2023-12-10) Liang, Xiaofan
    In our increasingly interconnected urban environment, the growth and expansion of network infrastructure play a pivotal role. This infrastructure encompasses transportation systems that facilitate movements and social amenities that foster community bonds, bringing influence and growth to a place. However, network infrastructure can also encode inequality and exclusion: barricaded highways, railways, and airports can replace local social infrastructure and impose physical barriers to local mobility flows; they are also prone to car-oriented urban forms that are unfriendly to pedestrians and bikers. Prior studies often focus on network infrastructure in its own locale or abstract it into spatial social networks, represented as nodes and edges on maps. Such simplification overlooks how network infrastructure sustains spatial and social connections in the built environment and fails to account for the complex and sometimes conflicting functions such infrastructure provides for different demographics and connection types. This dissertation introduces an exploratory framework about network duality, delving into the nuanced yet often contradictory dynamics of urban networks. This framework argues that connectivity is a multifaceted urban phenomenon embedded in network infrastructure that can induce duality, such as connecting one population while excluding the other, exhibiting influence in one system yet causing inequality in another, or co-existing with other infrastructure in some places but not others. Mitigating this duality is important for an inclusive and equitable network society. The critical inquiries are two-fold. First, what types of connectivity are prioritized or supported by urban infrastructure, for whom, at where, and at what cost? Second, what are some strategies (e.g., approaches, toolbox, and practices) that planners can use to mitigate the harmful effects of network infrastructure duality (e.g., exclusion and inequality), especially on marginalized communities? The three papers take different perspectives to answer these big questions. The first paper explores how the AeroATL Greenway Plan reconnects Aerotropolis communities when Hartsfield-Jackson Atlanta International Airport presents a barrier to local mobility flows. The second paper examines the social costs (such as losing social ties and memories) of demolishing a historic street for a new subway station in Guangzhou, China. The third paper answers where social infrastructure exists near subway stations and what factors influence the degree of their co-existence. All three papers use participatory computational approaches, including participatory GIS, participatory modeling, and volunteered geographic information from OpenStreetMap, to contest the inequality in the existing connectivity scheme.
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    Rethinking Megaregions: A Network Approach
    (Georgia Institute of Technology, 2023-04-27) Yoo, Chisun
    The emergence of a new scale, the megaregion, is one of the prominent issues in regional planning. Megaregions are concentrations of population, employment, and infrastructure and reflect the economic geography of countries, producing a majority of economic output. Accordingly, analyzing, delineating, and planning for megaregions are imperative in developing governance and policies, thereby assuring megaregions promote sustainability and economic competitiveness. One of the significant challenges is delineating megaregions. Well-defined boundaries are a desirable precondition for spatial planning at any scale. Nevertheless, the delineations of megaregions to date have several shortcomings, requiring new approaches. This dissertation delineated megaregions in the US using the network analysis approach, conceptualizing megaregions as a multiplex network of freight flow, human flow (commute & non-commute), chain and franchise business, and cultural connection networks. The first analysis constructed and analyzed the freight flow network between counties. Publicly available freight data was first disaggregated to the county level using a machine learning algorithm. Then the county-level freight flow network was constructed and analyzed. The second analysis used a private-sourced mobility pattern data that includes both commute and non-commute trips to identify the human flow network. These first two analyses examined the economic relationship that binds places into a megaregion. The third analysis constructed and analyzed a two-mode network consisting of chain and franchise business and their locations was constructed. The fourth analysis explored shared cultural identity among places by analyzing cultural heritages and their architectural styles. From the National Register of Historic Places data, a two-mode network consisting of two types of nodes – architectural styles and counties was constructed to identify regions connected by the traces of cultural heritages. In the final analysis, the networks were flattened with standardization and weighting, and analyzed to identify Cores, Sub-Cores, and Hinterlands of megaregions, as well as their functional regions. Ultimately, the dissertation delineated and proposed 12 new megaregions in the United States. These new megaregions consist of 124 Cores, 494 Sub-Cores, and 575 Hinterlands. Despite their small physical occupancy, the megaregions have more than 80% of population and employment, indicating their socioeconomic importance. This dissertation contributed to the literature and guides policymakers at different scales by identifying and delivering a comprehensive figure of megaregions in the US. By analyzing a set of different connections and spatial interactions, this dissertation provided the most comprehensive map of megaregions in the US. Furthermore, as the author explored several facets of megaregion forming, it contributed to several fields, including regional planning, transportation planning, regional economic development, regional governance, and cultural geography.
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    Social Learning for Social Transformation: A Case for Economic Democracy
    (Georgia Institute of Technology, 2022-03-14) Igietseme, Nene Veronica
    This research investigates planning theory and education from a critical race and radical planning perspective. While planning theory includes strands that explore the social determinants of health, regime power, and equity planning, it will often miss how these operate as interconnected economic, political, and ideological forces that maintain mass imprisonment, poverty, and neoliberalism as the dominant development paradigm. This study explores the relationship between racial capitalism, regime power, and collaborative rationality and the impact of capitalist institutions and planning on neighborhood development. It concludes with suggestions for the social learning that must occur in order to reorient students and professional planners, as well as the field, to social transformation.
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    Investigating Travel Behavior in Transit-Oriented Development: Toward Sustainable and Multimodal Mobility
    (Georgia Institute of Technology, 2021-12-14) Choi, Yunkyung
    An extensive literature has shown that transit-oriented development residents (TOD) have lower automobile use and diverse travel modes due to easy access to transit, better walkability, and proximity to various amenities. While such benefits of TOD are generally expected, the degree to which TODs influence travel behavior is still debatable. Besides, TOD implementation differs by context, and not all transit areas are developed along TOD principles. This variation in transit areas leads to different impacts on transportation outcomes. Although different TOD typologies have been developed in past studies, they are limited to a particular city or region. The other ongoing debate in land use and travel behavior field is the emergence of new mobility services that enable users to utilize a mode of transport on an as-needed basis. Recent advances in information technologies have facilitated new mobility services that meet travelers’ diverse needs, such as transportation network companies (TNCs), ridesharing, car sharing, bike sharing, microtransit, and shared autonomous vehicles. While new mobility services are expected to play an important role—either positive or negative—in planning how TODs can be implemented, the impacts and consequences of such services on traditional modes of transport such as public transit are still not well understood. In doing so, this dissertation investigates different modes of transportation in TOD areas by posing the following research questions: 1) do people walk more in transit-oriented developments? 2) are residents more multimodal in transit-oriented developments? and 3) what is the potential impact of new mobility services on public transit demand? For the first question, this dissertation addresses the effect of rail transit access on walking behavior in TOD areas. TODs are compared to other similar areas without rail transit access to determine whether people are more likely to walk in TODs for purposes other than transit use in Atlanta. The second question is addressed by identifying different TOD types on their impacts on residents’ multimodal behavior to capture various conditions of existing TODs and their heterogeneous outcomes. This research identifies different types of 4,400 transit areas—a half-mile buffer area from rail station—in the U.S. and develops several analytic models to explain the multimodal traveler behavior in the 2017 NHTS. The third question examines the potential impacts of TNCs on transit demand in Chicago, with a particular focus on understanding heterogeneity in the effects by employing fixed effects panel regression models. By investigating various travel behavior around transit station areas, this dissertation provides insights on how TODs can be better implemented to promote sustainable and multimodal travel behavior.
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    Assessing mental wellbeing in urban areas using social media data: understanding when and where urbanites stress and de-stress
    (Georgia Institute of Technology, 2021-12-10) Dutt, Florina
    Are Americans more stressed out by living in dense, urbanized areas or less dense, car-oriented areas? To answer this question, can we use people's expressions of stress in different environments to understand what kinds of spaces help them de-stress? This study uses stress levels of geolocated tweets to help us answer such inquiries and resolve the longstanding disparities between the field of psychology and urban planning about mental health impacts of cities. This is important because more than 75 percent of Americans are moderately stressed. Long-term stress is associated with mental health disorders, including sleeplessness, anxiety, and depression. Additionally, chronic stress is linked to physical ailments, including high blood pressure, cardiovascular diseases, and diabetes. The psychology literature claims that urban areas witness elevated levels of mental health problems, manifested as stress, mood disorders, and anxiety issues. Density, crowding, traffic, crime, and pollution are identified as stressors associated with urban living conditions. Contending this claim, the urban planning literature positions stress in the context of longer commutes, lack of accessibility, and social isolation that comes with suburban living conditions. Urban Planners and urban designers have advocated for density. With rapid urbanization, 60 percent of the world population will live in urban areas by 2030, making it crucial for urban planners to address these disparities to support the mental wellbeing of the urbanites. This research uses multi-headed attention transformer model to classify tweets (token sequences), and assesses the stress levels of custom-defined assessment grids of ten acres within the city area of Atlanta and Boston. The assessed stress level of these assessment grids is called the mental wellbeing score (MWS). Mental wellbeing score is defined in this research as a measure of `mental wellbeing' of any given grid (higher score is better). Using this measure, the research investigates the relationship between mental wellbeing and built environment characteristics in urban areas to uncover the impact of long-term stress triggered by the conditions of the built environment in urban settings. In summary, the results of the exploration shed light on three critical aspects: 1. Mental wellbeing score increases with increasing urbanness. 2. The mental wellbeing score increases with the increase in the diversity of escape facilities, including green parks, open spaces, and other points of interest. 3. The mental wellbeing score is positively impacted by accessible high-density spaces with high symbolic value. The research also investigates the impact of safety perception and socio-economic status on mental wellbeing scores. The results show that addressing socio-economic disparity, crime, and investment in green infrastructure can improve mental wellbeing of urbanites. The methods and findings of the research show that 'urban areas' can positively impact mental health if designed appropriately. Furthermore, this study can empower urban planners and policymakers to develop tools to assess the mental wellbeing of urbanites, adjust infrastructure needs, and improve the urban amenities that support mental wellbeing.
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    White Spatial Planning Practices: Deconstructing Narratives around Race, Space, and Privilege
    (Georgia Institute of Technology, 2021-10-29) OConnell, Katie
    Racial inequality in the United States persists across multiple measures of health, wealth, and education despite changes in laws and policies to end de jure segregation. One reason is the way representations of space reproduces cycles of benefit to white people. This dissertation seeks to answer a central question: What is the role of white privilege in the production of space? To answer the overarching question in this dissertation, I ask four supporting questions 1) what are the changes in Black-white equality since the 1950s across multiple measures, including education, criminal justice, citizenship rights, health, housing, and poverty? 2) what is the relationship between abstract space and white privilege? 3) what have been the dominant discourses used in Atlanta's planning-related documents that ultimately justified the displacement of Black communities during urban renewal and the BeltLine redevelopment projects? 4) what counter-narratives did Black communities in Atlanta use to challenge white spatialities? A better understanding of whiteness and space guides planners to reframe urban problems not as the disadvantages found in communities of color but that of reproducing benefits for white people.
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    Measuring Street-Level Walkability through Big Image Data and Its Associations with Walking Behavior
    (Georgia Institute of Technology, 2021-07-26) Koo, Bon Woo
    The built environment characteristics associated with walkability range from neighborhood-level urban form factors to street-level urban design factors. However, many existing walkability measures are primarily based on neighborhood-level factors and lack consideration for street-level factors. Neighborhood-level factors alone can be limited in representing various needs of pedestrians. While pedestrians seek to fulfill their needs for accessibility, safety, comfort, and pleasurability, neighborhood-level factors tend to be limited to capturing the accessibility of the built environment (i.e., having places to go to and being physically connected to those places). The high-order needs (i.e., safety from crime, comfort from vehicular traffic, and aesthetic pleasurability) can be more closely proxied by street-level factors. Also, past studies suggested that certain street-level factors may weaken (or strengthen) the effect of neighborhood-level factors on walking behavior, which can be particularly important for disadvantaged populations who tend to be less responsive to neighborhood-level factors. However, measuring street-level factors often requires extensive manual labor and tends to be resource-intensive, resulting in the omission of street-level factors in widely used walkability measures such as Walk Score. This dissertation uses street view images and computer vision to overcome these challenges in measuring street-level factors and expands the literature by examining their association with walking mode choice. This dissertation first applies a pre-trained computer vision model to street view images and measure mesoscale (i.e., a midlevel spatial scale between macro and microscale) factors of walkability. It finds that the mesoscale factors have a significant contribution to walking mode choice models, and the contribution is greater than that from neighborhood-level factors. Next, the dissertation develops a method for automatically auditing walkability factors in microscale (i.e., the smallest spatial scale that pertains to the most fine-grain design details and their qualities) using the combination of computer vision, street view images, and geographic information systems. The validation results demonstrate moderate to high reliability between audit results by automated audit method and a trained human auditor. Finally, the dissertation uses automatically audited microscale factors to unpack the reasons for the weaker relationship between neighborhood-level factors and disadvantaged populations’ walking behavior. The result shows that microscale factors play a sizable role in moderating the effect of neighborhood-level factors. Collectively, this dissertation demonstrates the potential of using street view images and computer vision for research on the built environment-walking relationship and for collecting data on street-level factors over expansive geographic areas, a task that has traditionally been prohibitively expensive. The theoretical and methodological contributions of this dissertation help urban planners and designers understand the physical condition of their cities at street-level and make targeted interventions that are effective and equitable.
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    The serious potential of fun games: a new model for public engagement
    (Georgia Institute of Technology, 2020-04-25) Barchers, Camille Victoria
    This dissertation examines the relationship between game playing and social learning in public participation activities and whether and to what extent participants demonstrate enhanced collaborative decision making (collective intelligence) as a result. This research highlights the potential of Internet Communication Technology (ICT) to advance public engagement activities and demonstrates how planners might practically and intentionally design small group activities to promote collaborative processes. This dissertation used an experimental research design to test the extent to which an online role-playing game created opportunities for participants to experience social learning and whether or not this intervention lead to differences in collective intelligence between control and treatment groups. Additional analysis was conducted to measure the extent to which reported social learning and collective intelligence influenced planning outcomes such as commitment, creativity and consensus. Results of this work clarify the importance of social learning as a variable of interest for planners. Treatment groups demonstrated more equal turn-taking in review of descriptive statistics and social learning was found to be positively correlated with perceptions of consensus. This research also provides new perspectives on public participation and civic engagement. The impacts of this research are important not only for planners, but for all institutions that rely on collaborative decision making and need to understand group processes.
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    Travel behavior dynamics from a longitudinal perspective in Indonesia
    (Georgia Institute of Technology, 2020-04-22) Widita, Alyas Abibawa
    This dissertation links urbanization phenomenon with the literature of travel behavior, particularly as it relates to its interaction with the built environment. The aim is to extend the collective understanding of how the dynamic characteristics of the built environment might influences travel behavior. In addressing this gap, this dissertation proposes three research questions using Indonesia as the case study. The first research question explores travel behavior changes from the lens of rural urban migration. It finds that relocating to urban areas could reduce household transportation expenditure, as a proxy for travel demand, by approximately ten percent relative to the ones who remained rural. The second research question addresses the natural growth aspect by examining how changes in the built environment influence transportation expenses over time for urban non movers. It finds the modest, inelastic, and insignificant relationship between gross household density and household transportation expenditure. The third research question examines which life stage could the built environment influences present walking behavior. It finds that higher exposure to dense environments during childhood could induce a greater likelihood of maintaining walking habits during adulthood. Collectively, results highlight the notion of ‘windows of opportunity’, where travel behavior might be shaped through life events and past experiences. Moreover, findings also underline the relative importance of compact and connected environments to shape travel behavior.