Global ETD Search

11	Roadside Ditch Design and Erosion Control on Virginia Highways Stallings, Sheila Lynne 23 September 1999 (has links) The state of roadside ditch design and performance has become a topic of concern for the Virginia Department of Transportation. Erosion failures of roadside ditches have occurred frequently enough to indicate that it may be desirable to revise the current design practice. Through the Virginia Transportation Research Council, VDOT has sponsored this research to investigate the state of design practice for these structures and to explore revisions to the design process resulting in a more economical design. To investigate the erosion problems, various VDOT personnel at each of Virginia's nine Construction Districts were interviewed with the intent to gain an understanding of roadside ditch performance in each District. When possible, field visits were made to sites experiencing erosion failure and soil samples were collected for analysis. In addition, experiences and design procedures in neighboring states were reviewed, with the objective of determining if similar problems have been experienced, and if so, how they have been addressed. The survey of other states included nine states, and a site visit to the Mount Airy District of the North Carolina Department of Transportation. A study of the literature relating to the hydraulic performance of unlined and lined ditches was also performed, with the objective of researching available stability criteria used in ditch design and determining if suitable values of Manning's n are being used in Virginia design. The results of this study presented in this thesis represent the best recommended roadside ditch design practice based on current available research. Recommendations include revisions to the current relationship of soil type and maximum allowable velocity, revisions to the application of Manning's n for various lining conditions, and suggestions to improve the overall design and construction process based on surveyed VDOT experience, surrounding states and current research. Future research will be necessary to improve the scientific bases for these recommendations / Master of Science roadway ditches ditch design Virginia Transportation Research Council Virginia Department of Transportation
12	Description and critical analysis of the management of road and transportation research in the Republic of South Africa Van der Walt, Nicolaas 07 1900 (has links) The dissertation gives the background to the need for management of roads and transportation research in the Republic of South Africa. The close co-operation between researcher and end-user of research findings in the above-mentioned fields and its application into practice, is described. The advent of autonomy of research institutions in 1986, highlighted the need for a structured approach for the management of road and transportation research. Tasks, previously undertaken mainly by the Division for Road and Transport Research of the Council for Scientific and Industrial Research on behalf of the South African road and transportation authorities, had to be taken over by the Department of Transport. A transition period of five years was given (from 1987 to 1992) to implement a suitable scientifically sound system. Details towards co-ordination and formalising of needs such as determination, prioritisation, allocation, funding and control of transportation research are given. / Public Administration and Management / M.A. (Public Administration) Autonomy of research Commercialisation and privatisation Department of Transport Formalising of needs Management Road and transportation research 388.072068
13	Description and critical analysis of the management of road and transportation research in the Republic of South Africa Van der Walt, Nicolaas 07 1900 (has links) The dissertation gives the background to the need for management of roads and transportation research in the Republic of South Africa. The close co-operation between researcher and end-user of research findings in the above-mentioned fields and its application into practice, is described. The advent of autonomy of research institutions in 1986, highlighted the need for a structured approach for the management of road and transportation research. Tasks, previously undertaken mainly by the Division for Road and Transport Research of the Council for Scientific and Industrial Research on behalf of the South African road and transportation authorities, had to be taken over by the Department of Transport. A transition period of five years was given (from 1987 to 1992) to implement a suitable scientifically sound system. Details towards co-ordination and formalising of needs such as determination, prioritisation, allocation, funding and control of transportation research are given. / Public Administration and Management / M.A. (Public Administration) Autonomy of research Commercialisation and privatisation Department of Transport Formalising of needs Management Road and transportation research 388.072068
14	Proposals for the co-ordination of formal public passenger transport in the Johannesburg area Wentzel, Frederick 28 August 2012 (has links) M.Comm. / Formal public transport has an important function to fulfill, both in terms of service provision and also in the broader context of the economy. This is so because so many workers live in dispersed areas and are dependent on public transport to arrive at work. This point is especially valid with regard to the Soweto area, which is one of the most heavily populated areas in South Africa, providing a large workforce to South Africa's most important economic region — the Witwatersrand. The main theme of this study is that all "formal" passenger transport operators in the Soweto area need to be integrated and that structural co-ordination should take place. This includes service provision in terms of routes and schedules as well as the ticketing system. This study provides an overview of the activities of the "formal" operators in the Soweto area. The conclusion that can be drawn is that the current "formal" service leaves considerable scope for improvement. It is also clear from the reports that have been quoted in this study that the minimum levels of service are not being achieved. Hence, this study proposes new road-based routes and schedules aimed at improving the coordination of bus and rail transport in the Soweto and surrounding areas. This study also proposes an integrated ticketing system, which is aimed at forming the basis for effective co-ordination. The purpose of these proposals is to assist the yet-to-be-established Transport Authorities to make decisions that will guide the co-ordination process in the right direction. The study also investigates other aspects that influence the "formal" public transport system. These include Government Policy, national objectives, ticketing systems and coordination. These aspects, combined with current research and schedules will be used as the basis where-upon new suggestions are made. The study emphasises that the suggestions made will not necessarily improve cost effectiveness but are primarily aimed at improving upon the current service. The study suggests however, that any additional funding that may be needed will be a moderate amount with regard to macro-economic variables, and at the same time will improve the quality of life of the community and will help in achieving national transport objectives as envisaged by the Moving South Africa study project. It is also suggested in this study that the time for meaningless debate is over and that the time has arrived to implement practical solutions with regard to the formal public passenger transport system in South Africa. Transportation and state - South Africa.
15	Understanding Travel Modes to Non-work Destinations: Analysis of an Establishment Survey in Portland, Oregon Muhs, Christopher D. 21 June 2013 (has links) During the past three decades, research in travel behavior has generally proceeded from broad-level, aggregate analysis of mode share--the proportions of walking, bicycling, transit, and vehicle travel occurring in traffic analysis zones, census tracts, neighborhood, or other geographical units--to fine-grained, disaggregate analysis of mode choices and other trip-making attributes at the individual level. One potential issue is whether there are differences in the types of conclusions drawn from results of analyses performed at these different levels, as these results directly inform transportation planning and policy. This thesis aims in part to confirm whether the types of conclusions drawn from different levels of analysis are different, and to what extent. We also examine the relationships between the built environment and non-work travel choices from a unique analysis perspective. To do this, we use data from a 2011 travel intercept survey in the Portland, Oregon metropolitan region that was administered at convenience store, bar, and restaurant establishments. We estimate, for each of the travel modes--walk, bicycle, and automobile--two analysis models: one binary logistic regression model for mode choice of the individual traveler going to the establishment and one multiple linear regression model for mode share of shoppers at the establishment. Both models control for socio-demographics, trip characteristics, and built environment measures of travelers. For the binary logistic regression models, the data are disaggregate and particular to the individual traveler. These models also controlled for attitudes and preference towards travel modes. For the multiple regression models, data are aggregated to the establishment. The built environment data in each model represent characteristics of urban form surrounding the establishment. The data being oriented to the destination-end of the trip, as well as providing controls on land use make this analysis unique in the literature, as most non-work travel studies use residential-based data. Results suggest that analyses performed at the two different levels provide policy-relevant but somewhat different conclusions. In general, characteristics of the individual and the trip have stronger associations with mode choices of individuals than when aggregated to the establishment and analyzed against the mode share patterns of shoppers. Instead, mode shares have stronger relationships with characteristics of the built environment. The built environment surrounding the destination has a much more pronounced association with mode shares at the establishment than with mode choices of individuals. The results highlight the usefulness of simple aggregate analysis, when appropriate. We also find large differences between modes in which characteristics are important for mode choice and mode share. Walking and automobile models behave somewhat similarly but in opposite directions, while bicycling behaves quite differently. These differences suggest on their own a move away from non-motorized travel to be considered as equivalent or assessed as one item in research and in practice. Civil Engineering Urban Studies and Planning
16	Transférabilité d'une modélisation-simulation multi-agents : le comportement inter-gares des voyageurs de la SNCF lors des échanges quai-train / Transferability of an agent-based model and simulation : the inter-station passengers behavior of SNCF passengers during platform-train exchanges Elleuch, Fatma 19 March 2019 (has links) Les travaux de cette thèse portent sur la définition et la validation d’une méthode de modélisation-simulation de foule permettant le transfert des principes et des mesures établis dans un contexte source d'observations vers des contextes cibles, non observables a priori. A partir de l'observation de comportements de piétons d’un contexte environnemental, social et urbain, nous inférons les règles et des motivations, rendant possible la modélisation et la simulation du comportement individuel de piétons dans ce contexte source, puis à évaluer la transférabilité du modèle dans un autre contexte cible. Nous appuyons nos travaux sur un cas réel. Il s’agit de la simulation du comportement des voyageurs entrants et sortants des trains dans une gare à fort trafic. Après une revue des théories, de modèles de simulation, nous retenons une approche basée sur la simulation microscopique d’agents sociaux, situés, basée sur les motivations. Nous argumentons le choix par le fait que, par rapport à une simulation de foule classique elle, a priori, l’avantage de favoriser la transférabilité. L’objectif de cette simulation est d’étudier, entre autres, les évolutions architecturales des stations permettant de raccourcir les temps d’arrêt des trains. / This thesis focuses on the definition and the validation of a crowd-simulation modeling method. This method allows transferring principles and measurements established in a source observation context to a target one. From the observation of pedestrian behavior in a social and urban context, our approach infers rules and motivations in order to model and simulate the individual pedestrian behavior in this source context. This allows, in a second step, to evaluate the transferability of the model to a given target context. Our work is based on a real case: the simulation of the passenger’s behavior while boarding and alighting trains (platform-train exchange) in a high-traffic station (dense situation). Starting from the state of the art of theories, models and types of simulation, we choose an approach based on the microscopic simulation of social agent’s motivation. This choice relies mainly on the fact that, compared to a classic crowd simulation, it has, a priori, a better transferability potential. The goal of this type of simulation is to study the architectural evolutions of the stations that could allow to control or shorten train dwell times. Système multi-Agents Modèle microscopique Transférabilité Approche motivationnelle Contexte Ferroviaire Recherche sur les transports Agent-Based system Microscopic model Transferability Motivational Approach Railway context Transportation research 003.3 302.330 113
17	GIS-based Episode Reconstruction Using GPS Data for Activity Analysis and Route Choice Modeling / GIS-based Episode Reconstruction Using GPS Data Dalumpines, Ron 26 September 2014 (has links) Most transportation problems arise from individual travel decisions. In response, transportation researchers had been studying individual travel behavior – a growing trend that requires activity data at individual level. Global positioning systems (GPS) and geographical information systems (GIS) have been used to capture and process individual activity data, from determining activity locations to mapping routes to these locations. Potential applications of GPS data seem limitless but our tools and methods to make these data usable lags behind. In response to this need, this dissertation presents a GIS-based toolkit to automatically extract activity episodes from GPS data and derive information related to these episodes from additional data (e.g., road network, land use). The major emphasis of this dissertation is the development of a toolkit for extracting information associated with movements of individuals from GPS data. To be effective, the toolkit has been developed around three design principles: transferability, modularity, and scalability. Two substantive chapters focus on selected components of the toolkit (map-matching, mode detection); another for the entire toolkit. Final substantive chapter demonstrates the toolkit’s potential by comparing route choice models of work and shop trips using inputs generated by the toolkit. There are several tools and methods that capitalize on GPS data, developed within different problem domains. This dissertation contributes to that repository of tools and methods by presenting a suite of tools that can extract all possible information that can be derived from GPS data. Unlike existing tools cited in the transportation literature, the toolkit has been designed to be complete (covers preprocessing up to extracting route attributes), and can work with GPS data alone or in combination with additional data. Moreover, this dissertation contributes to our understanding of route choice decisions for work and shop trips by looking into the combined effects of route attributes and individual characteristics. / Dissertation / Doctor of Philosophy (PhD) GPS time use diary episode extraction multinomial logit travel behavior mode detection episode reconstruction GIS map-matching route choice path size logit potential path area scale estimation Python ArcGIS activity analysis trip reconstruction smartphone global positioning system geographic information system toolkit work trip shop trip potential activity location land use activity episode travel episode stop episode transferability scalability modularity scripting big data travel survey respondent burden preprocessing multipath error tracking purpose detection segmentation data filter data smoothing fuzzy logic neural network decision tree rule-based algorithm trajectory point road network network dataset gateway shortest path horizontal dilution of precision HDOP commonality factor mode transfer point Halifax Nova Scotia Space-Time Activity Research variance inflation factor shapefile comma-separated values traveling salesman problem data mining branch-and-bound algorithm pedestrian network alternative route observed route route efficiency route attributes distance time heading bearing duration acceleration latitude longitude coordinate overlay analysis intersect shopping module data logger walk likelihood ratio test classification table path generation kappa statistic degrees data collection transportation research automate framework ArcToolbox spatio-temporal navigation positioning trace path spatial data topology horizontal accuracy SPSS Stata spatial resolution temporal resolution household survey trip reporting proximity analysis DMTI Desktop Mapping Technologies Inc. road intersection route overlap left turn right turn location analysis time geography spatial statistics buffer analysis cycling bus transit public transportation GEOIDE AGILE data need raw data urban canyon endpoint data cleaning elevation satellite outliers automatic processing nearest node classifier classification method short trip multi-point

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