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.
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.
Sketches Count: The Mies Van Der Rohe’s Dirksen Courthouse Archive Redrawn

(Georgia Institute of Technology, 2023-12-06) Park, James

Mies van der Rohe’s Everett McKinley Dirksen United States Courthouse in Chicago built in 1964 is arguably one of the most significant buildings in the history of judicial architecture in the United States and abroad because of its transformative role in the formulation of the conventions underlying contemporary courthouse design. Archived in the Mies van der Rohe Archive at the Museum of Modern Art New York, a significant resource associated with the design of the courthouse is the extensive documentation of the design process at the office of Mies. This body of work consists of 135 sketches, diagrams, and drawings, features alternative solutions, variational schemes, and sectional innovations, and provides an untapped resource to allow a closer look at the expressive range of the architectural language and the technical innovations proposed by one of the most influential architects of the twentieth century. The research takes on the Mies van der Rohe Archive and begins to flesh out the implicit design possibilities that the preliminary representations from the design process of the Dirksen Courthouse present: Are all these possibilities parts of the final scheme that was promoted in the end? If not, are there common themes that pervade each one of them? How important are some design ideas that belong exclusively to some of them but did not appear in the final design? To speculate these in depth, how much effort would it take to complete each of the design variations outlined by the preliminary representations? Can they be completed given the clues in the final design? If not, is it because they are not productive or they are just not compliant with the final scheme? In the end, how significant is this design process to contemporary courthouse design? The work here attempts to address these questions through a formal specification of a shape grammar that foregrounds common characteristics and unique ideas presented in the set of preliminary representations. Ambitiously, the work proposes a formal reconstruction of the final courtroom floor plan of the Dirksen Courthouse and an automated completion of the preliminary representations of key courtroom floor design variations from the design process of the courthouse, materializing the unrealized possibilities embodied in them. More specifically, a generative description of Mies van der Rohe’s courthouse design language is presented in the form of a shape grammar designed and implemented in the Shape Machine, a pioneering recursive shape rewriting technology. The grammar is proposed as an open-ended set of shape rules that can be readily expanded to complete an increasing number of design variations documented in the archive and generate some hypothetical ones that can be, in principle, generated by this dynamic grammar. Significantly, at any moment, new shape rules can be introduced seamlessly, as an intrinsic part of the design process of the grammar, without requiring the reformatting of existing rules or advocating the design of a singular Miesian grammar. The work concludes with a critical assessment of the sequences of the rule applications for the generation of complete courtroom floor plans. The contributions of the dissertation are (a) a generative description of Mies van der Rohe’s courthouse design language in the form of a shape grammar that is designed based on the final design of the Dirksen Courthouse and its design process documented in the Mies van der Rohe Archive at the Museum of Modern Art New York; (b) a formal reconstruction of the final courtroom floor plan of the courthouse; (c) an automated completion of the preliminary representations of key courtroom floor design variations from the design process of the courthouse; (d) a critical account on the significance of the design process of the courthouse in the contemporary courthouse design discourse with an emphasis on the innovative sectional idea of the courtrooms as an unrealized possibility in the making of the final courtroom floor plan, which still remains to be rediscovered in the designing of new courthouses; and (e) some speculations on the significance of the computational method developed for the research in the field of shape computation and on its potential role in bridging the gaps between sketching, diagramming, drafting, and modeling in the digital workflows of architects and designers.
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.
Blockchain-enabled Smart Contract System for Creating System-based Trust in Subcontracting Process

(Georgia Institute of Technology, 2023-03-27) Yoon, Jong Han

The unethical practices of bid shopping and peddling during the subcontractor procurement process can reduce trust between the general contractor (GC) and subcontractors (Subs) and lead to low-quality work, claims and disputes, schedule delays, and cost overruns. Despite the adverse impacts of these unethical practices on construction projects, the construction industry still lacks an ethical and trustworthy subcontracting process to prevent bid shopping and peddling. Furthermore, the transactional relationships between the GC and Subs in construction projects make profit-driven pursuits tempting, thereby increasing opportunistic behaviors. This dissertation contributes to the body of knowledge by developing a framework based on a blockchain-enabled smart contract system to address these unethical practices, thus establishing the subcontracting process grounded on system-based trust. Blockchain provides tamper-proof and decentralized data storage, and smart contracts enable an automatic contract execution by leveraging the data stored in Blockchain. The proposed framework employing the above advantages is demonstrated through a pilot test, and its feasibility and effectiveness are validated through a survey with nine professionals who had sufficient years of experience in the construction industry. The validation results show that the framework can prevent the aforementioned unethical practices and enable Subs to fairly compete for bid awards with proper budgets. In addition to the development of a subcontracting process leveraging a blockchain-enabled smart contract system, this dissertation contributes to the body of knowledge by providing a game-theoretic framework that the GCs and Subs can use to quantify and evaluate the outcomes of their strategic behaviors (e.g., trust-driven vs profit-driven behaviors) in the subcontracting process. Game theory in the framework enables mathematically analyzing and comparing the payoffs of strategic behaviors, using Nash Equilibrium. This dissertation also contributes to the body of knowledge by empirically verifying the effects of system-based trust created by a blockchain-enabled smart contract system on GCs’ and Subs’ strategic behaviors by conducting role-playing simulations. The developed game-theoretic-framework-based analysis of the simulations demonstrates that the blockchain-enabled smart contract effectively promotes trust-driven behaviors by enhancing system-based trust, thereby leading to a win-win game for the GC and Subs in the subcontracting process. These valuable findings establish the foundation for a transformative subcontracting process that is more ethical and grounded on system-based trust. Moreover, the findings can help the construction industry deepen its understanding of the significance of trust-driven behaviors in the subcontracting process. The findings also promote the enforcement of trust-driven behaviors by enhancing system-based trust through blockchain technology.
Enhancing Organizational Transformation for Design-Build Infrastructure Projects: Design Liability, Construction Quality Assurance, and New Engineering Leadership Requirements

(Georgia Institute of Technology, 2022-07-29) Lee, Jung Hyun

Major transportation infrastructure projects have used alternative project delivery, such as design-build (DB), to streamline and expedite project delivery, transferring many roles and responsibilities from state departments of transportation (DOTs) to private actors. One challenge that state DOTs face in their major DB projects is ensuring that the DB team upholds the highest standards of design and construction quality in the integrated design and construction environment. The overarching objectives of this study are to support decision-makers in streamlining project delivery by identifying challenges related to understanding gaps between public owners' expectations and the industry's perception and suggesting recommendations to mitigate the gaps. Most specifically, this study addresses issues found in DB transportation infrastructure projects and recommends innovative solutions to overcome those issues in the following areas: (1) design liability, (2) construction quality assurance, and (3) a new engineering leadership requirement on the DB team. This study utilizes a mixed-method research methodology, combining quantitative and qualitative techniques to identify key areas of variances in the integrated DB infrastructure projects. The data in this study come from a survey and semi-structured interviews. Because of the interdisciplinary nature of the research, it is necessary to capture several viewpoints from a wide range of subject-matter experts (SMEs) from multiple domains, including design consultants, highway contractors, public owners, owner representatives, insurance and legal advisors, and construction engineering and inspection (CEI) specialists. The results show that SMEs had considerably different perceptions regarding the frequency and severity of design claim sources in the DB environment. Inconsistencies between CEI perceptions and DOT requirements for quality assurance roles and responsibilities are identified. The results also highlight that a new engineering leadership requirement on the DB team will add value to large and complex projects. This study contributes to the body of knowledge in proactive design and construction quality management by providing decision-makers insights into design liability issues and opportunities to reduce them, providing guidance on reinforcing the quality assurance program for current and future DB projects, and mitigating gaps between the DOT's expectations and the industry's perceptions. The findings of this study have important implications for future practice and offer constructive guidance on streamlining project delivery in the DB transportation infrastructure market.
Haptic Interface Design Support: Assisting Designers in Analyzing the Design Space of and Prototyping Haptic Interfaces

(Georgia Institute of Technology, 2022-05-27) Lin, Hongnan

Haptic interfaces, which enable human-computer interaction through touch, have the potential to benefit a wide range of life activities, including communication, education, creation, entertainment, and transportation. The development of practical haptic interface design requires the involvement of designers with their user-centered design perspectives and creative design expertise. Designers entering the haptic domain need support. Previous efforts have focused on providing hardware and software platforms for designers to design haptic experiences on top. In this dissertation, we study how to support designers to create new haptic hardware with emerging technologies. Specifically, we focus on two main challenges: analyzing the design space of haptic interfaces and prototyping haptic interfaces. Our inquiry is embodied in two projects respectively: Hapticology and FlexHaptics. In both projects, we design, build, and evaluate artifacts, i.e. tools and approaches, to transform haptic interface design from its current state to a preferred state and reflect on implications for future efforts on supporting designing haptic interfaces. Hapticology project proposes a rational design process for haptic interfaces adapted from design space analysis and morphological analysis. It provides a combination of design artifacts needed to perform the analysis, including a space of design options, discussions of the impact of the design options, and data visualization of the design options and impacts. FlexHaptics project studies the prototyping problem, focused on passive haptic interfaces. FlexHaptics method to design passive haptic interfaces comprises the modules, mathematical models, and editor. It combines important advantages of previous techniques, including extensive and fine-tunable haptic profiles and computer-aided design and fabrication. It also introduces beam structures to the field of passive haptic interfaces, which benefit predictable haptic properties, accessible fabrication, and compact form factors. The workshop explores passive haptic inputs with novice designers using FlexHaptics method. It reveals the design process followed by novice designers, challenges encountered in designing haptic hardware, and informs implications for future design support for creating passive-haptic interfaces. The two projects form a T-shape research structure; Hapticology builds the horizontal line as it navigates through extensive possibilities of haptic interface designs, and FlexHaptics builds the vertical line as it focuses on one haptic interface type identified from Hapticology and dives into the design processes. Synthesizing the findings from the projects, we discuss haptic interface design processes integrating the outcomes of this work and depict a framework to promote innovation in haptic interfaces.
Development and evaluation of a design tool for occupational therapists to facilitate co-design of assistive technology with designers

(Georgia Institute of Technology, 2022-05-05) Lee, Su Jin

Development of effective assistive technology (AT) for individuals for disabilities necessitates close collaboration between occupational therapists (OTs) and designers. Currently, their successful collaboration is hampered by absence of a common language; as a result, clinical insight necessary for creating effective AT are poorly integrated into the design process. This problem can be attributed, in large part, to OTs’ inability to communicate with designers in design-actionable language. For successful ATs to be developed, OTs must be able to translate their clinical understanding of task-performance deficits into task-relevant design attributes that are necessary for designers to make informed design decisions. To enhance OT’s ability to communicate their expertise to designers and, therefore, be a better co-design partner in the co-design process, the aims of this dissertation were to: 1) develop the Dyadic Transfer Performance Instrument (DTPI), a tool designed to help OTs articulate, in design-relevant terms, clinical knowledge pertinent to designing AT interventions for caregiver-assisted transfers, 2) Conduct co-design workshops to engage OTs and designers to i) identify task-related problems with transfers from a pre-recorded video; ii) generate concepts for AT solutions, with and without DTPI, for a real-life case (based on a caregiving dyad experiencing transfer performance difficulties), and 3) Evaluate the usefulness of the DTPI, as measured by the extent to which its use: 1) increases OT’s active engagement in the co-design process; 2) increases OT’s use of design-relevant terms, and 3) improves the experience of participants during the co-design process. The primary output of this dissertation is a tool that empowers OTs to be co-equals in the co-design process, a pre-requisite for co-design teams to create more informative design criteria grounded in task-relevant design characteristics. The DTPI consists of several features: 1) a tag function that allow users to analyze environmental interactions during performance at fine-gained task levels, 2) prompts that facilitate consideration of all relevant design characteristics and attributes, and 3) compilation of data to easily visualize results in a way that supports generating design insights. Analysis of the co-design workshops indicate that the DTPI helps OTs to anchor their clinical assessments in more design relevant terms, increase the efficiency at which their assessments are communicated to designers, and increase their proactive contribution in the brainstorming phase of the co-design process. This project has several short- and long-term outcomes. Most immediately, it demonstrates the feasibility of a tool-mediated co-design method to foster more effective collaboration between OTs and designers. Adoption of more effective co-design methods will, over time, result in more effective AT solutions for transfer performance for which there are persisting unmet needs. Further, more effective AT solutions will improve transfer performance, thus enabling individuals aging with disability to remain at home longer, as well as reduce the physical strain on caregivers.
Human-building interaction: Supporting students’ performance and wellbeing through built environments on campus

(Georgia Institute of Technology, 2022-05-03) Kim, Yujin

Facility management aims to ensure buildings' quality and components to support occupants in achieving their goals and objectives. Campus environments play a vital role in student success by providing supportive spaces for learning, living, resting, and socializing. However, studies about the built environment of higher education have mainly focused on the ways of learning and teaching instead of physical components, and built environments on campus and their effects on students have been little studied. This study aims to 1) propose and investigate a theoretical framework on the relationship between built environments and students’ outcomes (i.e., academic performance and wellbeing) in higher education and 2) identify the preferred physical and functional environments on campus depending on student activities. This study proposed a theoretical framework based on the socio-materiality theory to explain the complex relationship between materiality and social practice in built environments. The proposed framework was tested in three-fold. First, study 1 investigated how students’ space usage of a library changed after the COVID-19 pandemic and was related to indoor environmental features. Data were collected via survey with 66 responses in pre-pandemic and interviews with 12 students during the pandemic. One of the main findings was that, even though students used the library less during the pandemic, they expected to use it as much as pre-pandemic or even more after the pandemic. Furthermore, students required different environmental features depending on their purpose of space usage, and the physical environment cultivated a sense of belonging and community. Second, study 2 tested the restorative effect in indoor settings using an eye-tracking device. Data were collected through a true experiment with 34 students randomly assigned to biophilic vs. non-biophilic design settings. The findings indicated that biophilic design itself was not decisive to restorative effects. Students in both settings selectively looked at nature-like (natural material) and views of nature and reported restoration effects. Lastly, study 3 analyzed how multi-dimensional environments (i.e., physical and functional environments) affected students’ outcomes in dormitories. A total of 128 self-reported survey responses revealed that the physical and functional environments were related to each other and directly and indirectly affected students’ perceived learning performance and wellbeing. In conclusion, this thesis provides a theoretical framework to explain the iterative process of physical and functional environments on campus and empirical evidence of the importance of built environments for enhancing student experiences and supporting different activities, such as learning, collaborating, socializing, and resting. For this, academic leadership, building managers, and designers should actively adopt the evidence-based design approach to provide appropriate environments and support student activities.
Product Model Exchange Standards for Cast-in-Place Reinforced Concrete: Implementation Methods, Value Considerations, and Application to Design Indicators

(Georgia Institute of Technology, 2022-04-27) Garcia Bottia, Leonardo

Building Information Modeling (BIM) has changed the way information in design and construction is communicated by allowing the possibility of exchanging project models and data together. To optimize the process, standards have been developed to define what is required in each exchange and how to represent it. For several years Cast-in-Place (CIP) reinforced concrete (RC), one of the most important construction materials worldwide, has been subject to considerable efforts toward the development of its standards. However, the monolithic nature of the material and its complex supply chain makes it difficult for this development to be properly carried out. This dissertation presents the results of a study with four key aims: (1) identify how exchange standards for CIP RC fit into current engineering and construction practices, (2) develop the requirements and methods for implementation, (3) study the value considerations of implementing the standards in practice, and (4) apply the information available in exchange standards to enhance the design and construction processes through the estimation of design indicators. This research is developed in the context of the undergoing efforts of the American Concrete Institute (ACI) to develop industry-wide standards for CIP RC concrete. To map the current engineering practices and challenges regarding CIP RC model exchanges, the dissertation presents the results of an ethnographic-action study performed to allow a description of current behaviors, the acquisition of qualitative data regarding the advantages of implementing BIM standards on a practical level, and to inform of potential additional requirements for standardization. To assist the implementation of standards in practice, this dissertation presents a set of methods for implementation that adapt to current tools and practices. To study the value considerations of implementing exchange standards, the same CIP RC processes captured in the ethnographic study are reproduced using the methods developed for model exchange standards. Finally, the study presents the results of a logistic regression model developed to use the parametrized information made available through these exchanges, to estimate indicators that improve the design and construction processes. In conclusion, this research provides recommendations to further develop CIP RC modeling and exchange standards, studies how design and construction practice aligns with new CIP RC standard workflows, provides methods for implementation, and develops a model useful to predict design indicators during early stages using the valuable information embedded in CIP RC exchange standards.