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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Seamless urban topographies: Integrating New Orleans' hard and soft infrastructure

January 2017 (has links)
The introduction of the automobile drastically changed the urban fabric of our cities. Cars offered unprecedented mobility, so middle-class Americans fled cities in the endless pursuit of personal space. It became necessary to construct a vast network of infrastructure to accommodate the infinite expansion of peripheral districts. So, in the mid-20th century, public works projects were undertaken throughout the country in order to modernize cities around the vehicle. There was great excitement over the engineering feat of the elevated freeway as "an urban sculpture for motion." 1 However, the inevitable enormity of vehicular infrastructure became problematic in historically dense urban centers. Architects and planners accepted the increasing importance of the automobile but were wary of its imposing infrastructure. They understood both the potential of freeways for expansion, as well as the drawbacks of their "mere physical form ... sheer bigness and muscularity." 2 Earlier projects were more mindful of urbanistic principles integrating topography and pedestrian movement into a sectionally-rich infrastructure. There were theoretical projects suggesting a "multilevel metropolis" 3 that argued for the careful integration of buildings and alternative transportation as a way to mitigate the impact of daunting elevated structures. Unfortunately, the rapid expansion of the interstate system began to ignore these strategies. Instead, most cities received the universally engineered solution to simply elevate the highway and obliterate anything in its path. Furthermore, the insertion of massive highway infrastructure occurred overwhelmingly through lower-class neighborhoods under the guise of fixing urban blight. Once vibrant neighborhoods were plowed over with asphalt and isolated from the rest of the city. Some fifty years later, the relevance of the automobile is dwindling, and designers are questioning this invasive highway infrastructure. The elevated highway became a physical and perceptual barrier that has inhibited the growth of countless urban communities. While the simplistic solution argues total removal, or capping, this process is expensive, unsustainable, and only masks the problem. These structures have a legacy and permanence as an architectural element, and have the potential to be part of a larger system for mobility. This thesis argues for the return to more sustainable solutions for a multilevel urban condition with the capacity to reconnect isolated spaces. / 0 / SPK / specialcollections@tulane.edu
2

Bundling Effects on Contract Performance of Highway Projects: Quantitative Analysis and Optimization Framework

Yu Qiao (6855683) 02 August 2019 (has links)
<div>The practice of project bundling, which involves combining multiple projects into a single multi-project contract, is in increased use at infrastructure agencies. Researchers have shown that this practice potentially reduces project cost but could cause undesirable consequences such as reduced market competition. For this reason, bundling policy needs to be guided by a determination of whether specific projects should be bundled, the bundling strategy in terms of bundle size, bundling combinations, geographical locations, and project scheduling, and the resulting outcome of each strategy in the terms of contract performance (overall cost and time duration, and cost and time overrun). Practitioners seeking answers to these questions continue to be stymied by the lack of quantified relationships between bundling alternatives and the resulting contract performance.</div><div>This dissertation addresses these questions by analyzing empirical data including the costs and durations of highway contracts and projects over a ten-year period. Using a variety of modeling approaches, the dissertation developed models to quantify the effects of bundling-related factors on the key contract performance measures (CPMs). The bundling related factors are contract size, bundle size, project combinations, project similarity and spatial proximity between bundled projects, and the CPMs are project cost and time performance, market competition, and the risks of cost overrun and project delay. Through the modeling process, the dissertation measured the effects of project similarity, economies of scale, economies of bundling, and economies of competition on bundling, and developed a novel technique to measure similarities between projects. Using the developed models, the dissertation then established an optimization framework to identify cost-effective bundling strategies. A greedy approach that minimizes the overall cost in a polynomial time was proposed to obtain heuristic solutions. The outcomes of this dissertation are twofold: first, it provides highway agencies with a quick, convenient and robust tool to design long-term cost-effective bundling strategies for any given pool of candidate projects; secondly, it provides guidelines and directions for future bundling policy formulation or evaluation. </div>
3

Impact of performance goal on the needs of highway infrastructure maintenance

Jaipuria, Sunny 14 February 2011 (has links)
Performance goals for a highway system are an indication of the desired system condition, and the level of service to be provided to its users. Setting the appropriate performance goals has a significant impact on the way highway agencies conduct business. With growing needs and limited resources, the consequences of setting different levels of performance goals should be examined and compared to optimize the highway infrastructure needs at the network level. Three interacting sets of costs are typically considered for a complete economic appraisal of highway projects: construction, maintenance and road use costs. Due to the shift in focus from design-and-build mode to the repair-and-maintain mode, this study focuses on maintenance related costs and the road user cost aspects only. Maintenance and rehabilitation activities on pavement infrastructure are ongoing processes that are required for the entire road network. This suggests that for long planning horizons and geographically extensive networks, their application usually results in significant financial needs. Typically, highway agencies have based their policy decisions such as the target condition levels for the system on the budget needs for maintenance and rehabilitation actions. Since in most cases, the funding needs exceed the available budget, the required preventive and routine maintenance activities suffer or are overlooked completely. Failure to timely apply these maintenance actions cause the pavements to deteriorate more rapidly into condition states that require for more expensive rehabilitation actions during the life cycle of the pavement. Over time, a vicious cycle is instigated in which the maintenance and rehabilitation needs of the network keep increasing each year. Although most highway administrators acknowledge the fact that pavement preservation is perhaps the most effective way of using the limited budgets available, the costs associated with deferring maintenance actions is oftentimes overlooked when establishing performance goals for the system. Road user costs in the form of costs for vehicle operation have been recognized as another large component of the total transportation related costs. These costs are then arguably the most important to consider for a complete economic appraisal. Ironically, they are also often disregarded while making important policy decisions. Other road user costs such as those related to the impact of traffic congestion and detours caused by construction and maintenance activities are difficult to quantify and were not accounted for in this study. Although it is widely accepted that establishing suitable performance goal is critical for system maintenance and preservation, a framework that considers the inter-relationship between conflicting objectives of minimum maintenance and rehabilitation costs, deferred maintenance costs, and vehicle operating costs to the users does not exist. This thesis proposes a methodological framework that is aimed at assisting highway agencies with the problem of objectively analyzing policy decisions in terms of the performance goals for their highway networks that would minimize the total transport costs to the society. In a case study of the proposed framework, the highway network managed by the Texas Department of Transportation was examined for different performance goals. The results from the case study indicate that setting lower performance goals lead to savings in the M&R needs, but at the same time, they also significantly increase the exogenous costs such as deferred maintenance costs and the vehicle operating costs. / text
4

Business Strategies to Improve On-Time Deliveries and Profits in Southcentral Alaska

Leaver II, Donald Richard 01 January 2015 (has links)
Traffic congestion can cause late deliveries, decreased profits from vehicle fuel idling in traffic, and delayed distribution in tight delivery windows. The focus of this study was on developing strategies that business leaders could use to increase on-time deliveries. The conceptual frameworks for this case study were systems theory, traffic equilibrium theory, bathtub theory, and kinematic wave theory. Data were collected from semistructured interviews with 6 delivery service leaders from 3 delivery businesses in Southcentral Alaska. In addition, secondary data were collected from government information. Interview responses were coded to identify trends including delivery time, business activity, and amount of roadway congestion. Two major themes emerged from the interviews: time of day affecting when traffic congestion occurred, and limited alternate transportation routes causing congestion in Southcentral Alaska. The findings indicated that the best strategy to help reduce traffic congestion involved instituting toll optimization and high occupant vehicles lanes. The implications for effecting social change include how business leaders can help reduce traffic congestion using toll optimization, and how high occupant vehicle lanes could encourage Southcentral Alaskans to carpool.
5

EIXO DE INTEGRAÇÃO VIÁRIA: IMPACTOS ECONÔMICOS E SOCIAIS DA BR 158 SOBRE AS CIDADES DO VALE DO ARAGUAIA MATO-GROSSENSE ENTRE 2000 E 2014

Demambro, Elizeu 07 March 2017 (has links)
Submitted by admin tede (tede@pucgoias.edu.br) on 2017-05-12T15:03:52Z No. of bitstreams: 1 ELIZEU DEMAMBRO.pdf: 2164594 bytes, checksum: 554f8463ef31b4577e5aa7e6b4f140f4 (MD5) / Made available in DSpace on 2017-05-12T15:03:52Z (GMT). No. of bitstreams: 1 ELIZEU DEMAMBRO.pdf: 2164594 bytes, checksum: 554f8463ef31b4577e5aa7e6b4f140f4 (MD5) Previous issue date: 2017-03-07 / This study seeks to determine the economic and social impacts that highway infrastructure projects caused in cities in the state of Mato Grosso, situated along the BR 158 Highway, such as Barra do Garças, Água Boa, Canarana and Confresa, in the period from 2000 to 2014. Firstly, the role of highway infrastructure investments in promoting the expansion of large monocultures, such as soybeans and corn, was identified. Then, the socioeconomic profile of the region of influence of the BR 158 Highway was characterized, encompassing demography, flow of employment, economic production, exports and imports of the cities, and other items. The study also verified the effects of highway infrastructure investments in the cities in question, in relation to small and medium-sized industrial and commercial segments. Lastly, it identified the goods that are transported and the highway support conditions from the perspective of truck drivers. The methodology used, which was quantitative and qualitative in nature, was supported by instruments, such as observation, interviews, document research and a literature review, with the data presented in the form of comments and tables. In assessing the economic and social impacts of the production changes in the Brazilian cerrado (tropical savanna ecoregion), as a result of highway infrastructure projects, the objective is to help explain the process of regional integration in Mato Grosso, in the current period, and chart it for the upcoming years, based on the infrastructure projects in question. / Com este trabalho procurou-se descobrir quais os impactos econômicos e sociais que as obras de infraestrutura viária desencadearam em municípios matogrossenses, situados ao longo da rodovia BR 158, como Barra do Garças, Água Boa, Canarana e Confresa, no período compreendido entre 2000 e 2014. Primeiramente, identificou-se o papel dos investimentos em infraestrutura rodoviária no estímulo à expansão das grandes monoculturas agrícolas, soja e milho. Na sequência, fez-se uma caracterização do perfil socioeconômico da região de influência da rodovia BR 158, abrangendo demografia, fluxo de emprego, produção econômica, exportação e importação dos municípios, entre outros. Também identificou-se a repercussão dos investimentos em infraestrutura rodoviária nos municípios em questão, para os pequenos e médios segmentos industriais e comerciais e, para finalizar, identificaram-se as mercadorias que são transportadas e as condições de suporte da rodovia na perspectiva dos caminhoneiros. A metodologia utilizada, de natureza quanti-qualitativa, foi auxiliada por instrumentos, como: a observação, a entrevista, a pesquisa documental e bibliográfica, sendo os dados apresentados, em forma de comentário e de tabelas. Ao avaliar os impactos econômicos e sociais das transformações produtivas, na área do cerrado brasileiro, derivados das obras de infraestrutura de rodovias, esperou-se contribuir para explicar a natureza do processo de integração regional em Mato Grosso, no período atual, e projetá-lo para os próximos anos, com base nas obras de infraestrutura em questão.
6

Business Strategies to Improve On-Time Deliveries and Profits in Southcentral Alaska

Leaver II, Donald Richard 01 January 2015 (has links)
Traffic congestion can cause late deliveries, decreased profits from vehicle fuel idling in traffic, and delayed distribution in tight delivery windows. The focus of this study was on developing strategies that business leaders could use to increase on-time deliveries. The conceptual frameworks for this case study were systems theory, traffic equilibrium theory, bathtub theory, and kinematic wave theory. Data were collected from semistructured interviews with 6 delivery service leaders from 3 delivery businesses in Southcentral Alaska. In addition, secondary data were collected from government information. Interview responses were coded to identify trends including delivery time, business activity, and amount of roadway congestion. Two major themes emerged from the interviews: time of day affecting when traffic congestion occurred, and limited alternate transportation routes causing congestion in Southcentral Alaska. The findings indicated that the best strategy to help reduce traffic congestion involved instituting toll optimization and high occupant vehicles lanes. The implications for effecting social change include how business leaders can help reduce traffic congestion using toll optimization, and how high occupant vehicle lanes could encourage Southcentral Alaskans to carpool.
7

Interchange Intervention: Inhabiting Urban Highway Infrastructure

Ashraf, Mohammed Imtiaz 18 November 2013 (has links)
Urban highway infrastructure in North America has been singularly designed for the automobile, severing parts of the urban fabric, blighting our once-thriving city centres and resulting in spaces that are void of the human scale. The Cogswell Interchange in Halifax, Nova Scotia, Canada is such an infrastructure, cutting through the downtown core and heritage district. This thesis investigates the Cogswell Interchange in an attempt to animate and enliven a dead urban space, reducing traffic and bringing new activity and life to the street. Reappropriating parts of vehicular infrastructure for cyclist and pedestrian use and creating a variety of activities and programs (gallery, gym, restaurant, park) enables an increased connectivity for pedestrians and cyclists and brings a more human-scale urbanity to the site. The infrastructure itself becomes a framework upon which to build, revisioned as an active, vibrant place which people can experience with a renewed sense of wonder and appreciation.
8

VEHICLE AUTONOMY, CONNECTIVITY AND ELECTRIC PROPULSION: CONSEQUENCES ON HIGHWAY EXPENDITURES, REVENUES AND EQUITY

Chishala I Mwamba (11920535) 18 April 2022 (has links)
Asset managers continue to prepare physical infrastructure investments needed to accommodate the emerging technologies, namely vehicle connectivity, electrification, and automation. The provision of new infrastructure and modification of existing infrastructure is expected to incur a significant amount of capital investment. Secondly, with increasing EV and CAV operations, the revenues typically earned from vehicle registrations and fuel tax are expected to change due to changing demand for vehicle ownership and amount of travel, respectively. This research estimated (i) the changes in highway expenditures in an era of ECAV operations, (ii) the net change in highway revenues that can be expected to arise from ECAV operations, and (iii) the changes in user equity across the highway user groups (vehicle classes). In assessing the changes in highway expenditures, the research developed a model to predict the cost of highway infrastructure stewardship based on current and/ or future system usage. <div><br></div><div>The results of the research reveal that CAVs are expected to significantly change the travel patterns, leading to increased system usage which in turn results in increased wear and tear on highway infrastructure. This, with the need for new infrastructure to support and accommodate the new technologies is expected to result in increased highway expenditure. At the same time, CAVs are expected to have significantly improved fuel economy as compared to their human driven counterparts, leading to a decrease in fuel consumption per vehicle, resulting in reduced fuel revenues. Furthermore, the prominence of EVs is expected to exacerbate this problem. This thesis proposed a revision to the current user fee structure to address these impacts. This revision contains two major parts designed to address the system efficiency and equity in the near and long term. For the near term, this thesis recommended a variable tax scheme under which each vehicle class pays a different fuel tax rate. This ensures that both equity and system efficiency are improved during the transition to ECAV. In the long term, this thesis recommended supplementing the fuel tax with a distance based VMT tax, applicable to electric vehicles.<br></div>

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