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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.
11

Método para análise da consistência geométrica de rodovias brasileiras de pista simples

García, Daniel Sergio Presta January 2008 (has links)
Via, condutor e veículo são os principais componentes de um sistema viário. A segurança viária decorre de como estes agentes se relacionam entre si. Esta relação pode ser avaliada através da velocidade operacional que o condutor aplica em seu veículo segundo a percepção de conforto e segurança repassada pela rodovia. A análise da consistência geométrica é uma ferramenta de análise para rodovias de pista simples que permite identificar o padrão de utilização das mesmas, através de modelos de estimativa da velocidade operacional e de critérios classificatórios. A análise de consistência geométrica vem sendo utilizada como ferramenta para avaliar problemas de projeto e operação de rodovias existentes e em projeto. A Federal Highway Administration – FHWA recomenda a utilização deste tipo de análise para avaliar a segurança viária de rodovias de pista simples. Os modelos utilizados na análise de consistência geométrica estão calibrados para condicionantes culturais do condutor, de veículos e de rodovias dos Estados Unidos. Assim, a aplicação direta do software IHSDM – Interactive Highway Safety Design Model em rodovias de pista simples do Brasil não é recomendada. A presente Tese propõe um método para análise da consistência geométrica de rodovias brasileiras de pista simples. O método utiliza modelos próprios para estimativa da velocidade operacional, critérios de aplicação das taxas de aceleração e desaceleração e propõe um índice para classificação das rodovias por quilômetro e por trecho: o ICG (índice de consistência geométrica). No estudo de caso, 14 trechos rodoviários, totalizando 225 quilômetros, são submetidos à análise pelo método proposto. A classificação obtida é confrontada com quatro índices de acidentes distintos, resultantes de uma base de dados de acidentes de seis anos, com 14.608 ocorrências. O resultado deste confronto apresenta uma correlação entre o índice de consistência geométrica por trecho, proposto, e o índice de acidentes totais e parciais de 0,59. O valor obtido confirma a relação prevista entre a freqüência de acidentes e indicadores de consistência geométrica, verificada pela FHWA, surpreendendo pela sua intensidade. O melhor desempenho do índice proposto é associado a sua composição, contemplando os critérios de segurança I (consistência do projeto) e II (consistência da velocidade operacional) e ao comportamento verificado em condutores brasileiro, menos sensíveis a restrições geométricas. / The highway, the individual users and the vehicle are the main agents of a traffic system. Traffic safety is determined by how these agents interconnect. Such relation may be assessed by the observation of the operational speed the driver uses in the vehicle according to his perception of comfort and safety of the roadways. The design consistency analysis is an assessment tool for rural two-lane highways which allows the identification of their usage patterns by using operational speed estimate models and sorting criteria. The design consistency analysis has been used as a tool to assess project and operation flaws of existing highways and projects to construct new highways. The Federal Highway Administration – FHWA recommends the use of this kind of analysis to assess the traffic safety of rural two-lane highways. The models used for the design consistency analysis are calibrated to the conditional cultural aspects of United States of America’s drivers, vehicles and highways. Therefore, the straight application of IHSDM – Interactive Highway Safety Design Model software in Brazilian rural two-lane highways is not recommended. This doctoral thesis aims at presenting a method of design consistency analysis of Brazilian rural two-lane highways. Such method uses original models for estimating the operational speed, new criteria for application of acceleration vehicle dynamics rate and introduces a new index to classify highways by kilometer and by segment: the ICG or Design Consistency Index. In this case study, 14 roadway segments – of a total of 225 kilometers – were analyzed by the proposed method. The resulting classification was compared to four other accident indexes from a database of 14,608 official records collected in six years. The result of this comparison leads to a correlation between the proposed design consistency index by highways segment and the total and partial accident index of 0.59. The result confirms the foreseen relation between the accident frequency and the design consistency indicators verified by FHWA – and its intensity is astonishing. The best performance of the proposed index is associated to its composition, which involves the safety criteria I (design consistency) and II (operational speed consistency), and to the behavior observed in Brazilian drivers, less sensitive to geometric restrictions.
12

<b>New Approaches to Improving Highway Design, Safety, and Visual Presentation</b>

Xiaoqiang Hu (17485461) 30 November 2023 (has links)
<p dir="ltr">Accurate traffic information plays a crucial role in developing appropriate pavement designs. However, the existing traffic design input module often falls short in accurately describing the real traffic conditions on Indiana highways. Furthermore, a range of issues related to vehicle classification, transit bus traffic characterization, semi-truck platooning, pavement friction assessment, and highway model representation have been identified. This study aims to improve the design, safety, and visual presentation of highways in Indiana. In the realm of design, real-world traffic data will be collected and processed, while a traffic database of urban buses will be established. Both an axle-based digital classification method and a model-based image classification method will be introduced to categorize unclassified vehicles. The updated vehicle class distributions and axle load distributions will serve as pivotal traffic inputs for pavement design. Regarding safety considerations, a model for two-semi-truck platooning will be developed to determine safe and optimal headways. Characteristics pertinent to semi-truck platoons will be outlined and discussed. Additionally, a series of laboratory and field tests will be conducted to assess the frictional properties and performance of aggregates and colored pavements, thereby refining roadway safety measures. In the realm of visual presentation, the Building Information Modeling (BIM) framework will be applied to convert, enrich, and extend a highway model. A BIM-centered repository will be created, amalgamating a wealth of information encompassing traffic specifics and project particulars into an integrated visual platform. Moreover, Open BIM processes will be implemented, streamlining the exchange of highway data and ensuring seamless compatibility of models. The results of this study can offer valuable insights to drive improvements in highway design, safety, and visual presentation throughout Indiana.</p>
13

Improved road design for future maintenance : analysis of road barrier repair costs

Karim, Hawzheen January 2008 (has links)
<p>The cost of a road construction over its service life is a function of the design, quality of construction, maintenance strategies and maintenance operations. Unfortunately, designers often neglect a very important aspect which is the possibility to perform future maintenance activities. The focus is mainly on other aspects such as investment costs, traffic safety, aesthetic appearance, regional development and environmental effects.</p><p>This licentiate thesis is a part of a Ph.D. project entitled “Road Design for lower maintenance costs” that aims to examine how the life-cycle costs can be optimized by selection of appropriate geometrical designs for the roads and their components. The result is expected to give a basis for a new method used in the road planning and design process using life-cycle cost analysis with particular emphasis on road maintenance.</p><p>The project started with a review of literature with the intention to study conditions causing increased needs for road maintenance, the efforts made by the road authorities to satisfy those needs and the improvement potential by consideration of maintenance aspects during planning and design.</p><p>An investigation was carried out to identify the problems which obstruct due consideration of maintenance aspects during the road planning and design process. This investigation focused mainly on the road planning and design process at the Swedish Road Administration. However, the road planning and design process in Denmark, Finland and Norway were also roughly evaluated to gain a broader knowledge about the research subject. The investigation was carried out in two phases: data collection and data analysis. Data was collected by semi-structured interviews with expert actors involved in planning, design and maintenance and by a</p><p>review of design-related documents. Data analyses were carried out using a method called “Change Analysis”. This investigation revealed a complex combination of problems which result in inadequate consideration of maintenance aspects. Several urgent needs for changes to eliminate these problems were identified.</p><p>Another study was carried out to develop a model for calculation of the repair costs for damages of different road barrier types and to analyse how factors such as road type, speed limits, barrier types, barrier placement, type of road section, alignment and seasonal effects affect the barrier damages and the associated repair costs. This study was carried out using a method called the “Case Study Research Method”. Data was collected from 1087 barrier repairs in two regional offices of the Swedish Road Administration, the Central Region and the Western Region. A table was established for both regions containing the repair cost per vehicle kilometre for different combinations of barrier types, road types and speed limits. This table can be used by the designers in the calculation of the life-cycle costs for different road barrier types.</p>
14

Improved Road Design for Future Maintenance - Analysis of Road Barrier Repair Costs

Karim, Hawzheen January 2008 (has links)
The cost of a road construction over its service life is a function of the design, quality of construction, maintenance strategies and maintenance operations. Unfortunately, designers often neglect a very important aspect which is the possibility to perform future maintenance activities. The focus is mainly on other aspects such as investment costs, traffic safety, aesthetic appearance, regional development and environmental effects. This licentiate thesis is a part of a Ph.D. project entitled “Road Design for lower maintenance costs” that aims to examine how the life-cycle costs can be optimized by selection of appropriate geometrical designs for the roads and their components. The result is expected to give a basis for a new method used in the road planning and design process using life-cycle cost analysis with particular emphasis on road maintenance. The project started with a review of literature with the intention to study conditions causing increased needs for road maintenance, the efforts made by the road authorities to satisfy those needs and the improvement potential by consideration of maintenance aspects during planning and design. An investigation was carried out to identify the problems which obstruct due consideration of maintenance aspects during the road planning and design process. This investigation focused mainly on the road planning and design process at the Swedish Road Administration. However, the road planning and design process in Denmark, Finland and Norway were also roughly evaluated to gain a broader knowledge about the research subject. The investigation was carried out in two phases: data collection and data analysis. Data was collected by semi-structured interviews with expert actors involved in planning, design and maintenance and by a review of design-related documents. Data analyses were carried out using a method called “Change Analysis”. This investigation revealed a complex combination of problems which result in inadequate consideration of maintenance aspects. Several urgent needs for changes to eliminate these problems were identified. Another study was carried out to develop a model for calculation of the repair costs for damages of different road barrier types and to analyse how factors such as road type, speed limits, barrier types, barrier placement, type of road section, alignment and seasonal effects affect the barrier damages and the associated repair costs. This study was carried out using a method called the “Case Study Research Method”. Data was collected from 1087 barrier repairs in two regional offices of the Swedish Road Administration, the Central Region and the Western Region. A table was established for both regions containing the repair cost per vehicle kilometre for different combinations of barrier types, road types and speed limits. This table can be used by the designers in the calculation of the life-cycle costs for different road barrier types.
15

Improved road design for future maintenance : analysis of road barrier repair costs

Karim, Hawzheen January 2008 (has links)
The cost of a road construction over its service life is a function of the design, quality of construction, maintenance strategies and maintenance operations. Unfortunately, designers often neglect a very important aspect which is the possibility to perform future maintenance activities. The focus is mainly on other aspects such as investment costs, traffic safety, aesthetic appearance, regional development and environmental effects. This licentiate thesis is a part of a Ph.D. project entitled “Road Design for lower maintenance costs” that aims to examine how the life-cycle costs can be optimized by selection of appropriate geometrical designs for the roads and their components. The result is expected to give a basis for a new method used in the road planning and design process using life-cycle cost analysis with particular emphasis on road maintenance. The project started with a review of literature with the intention to study conditions causing increased needs for road maintenance, the efforts made by the road authorities to satisfy those needs and the improvement potential by consideration of maintenance aspects during planning and design. An investigation was carried out to identify the problems which obstruct due consideration of maintenance aspects during the road planning and design process. This investigation focused mainly on the road planning and design process at the Swedish Road Administration. However, the road planning and design process in Denmark, Finland and Norway were also roughly evaluated to gain a broader knowledge about the research subject. The investigation was carried out in two phases: data collection and data analysis. Data was collected by semi-structured interviews with expert actors involved in planning, design and maintenance and by a review of design-related documents. Data analyses were carried out using a method called “Change Analysis”. This investigation revealed a complex combination of problems which result in inadequate consideration of maintenance aspects. Several urgent needs for changes to eliminate these problems were identified. Another study was carried out to develop a model for calculation of the repair costs for damages of different road barrier types and to analyse how factors such as road type, speed limits, barrier types, barrier placement, type of road section, alignment and seasonal effects affect the barrier damages and the associated repair costs. This study was carried out using a method called the “Case Study Research Method”. Data was collected from 1087 barrier repairs in two regional offices of the Swedish Road Administration, the Central Region and the Western Region. A table was established for both regions containing the repair cost per vehicle kilometre for different combinations of barrier types, road types and speed limits. This table can be used by the designers in the calculation of the life-cycle costs for different road barrier types. / QC 20101112

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