Thesis (Civil Engineering)--École polytechnique fédérale de Lausanne, 2002. / PDF document ; contains 333 pages, with illustrations and charts (some col.). "Thèse no. 2568 (2002)." Includes bibliographical references.

Thesis (M.S.)--Virginia Polytechnic Institute and State University, 1991. / Vita. Abstract. Includes bibliographical references (leaves 70-73). Also available via the Internet.

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Ground transportation systems are essential for the mobility of people, goods and services. Thus, making sure these systems are resilient to the impact of natural and man-made disasters has become a top priority for engineers and policy makers. One of the major obstacles for increasing the resilience of ground transportation systems is the lack of a measuring framework. Such measuring framework is critical for identifying needs, monitoring changes, assessing improvements, and performing cost-benefit analysis. This research addresses this problem by developing a traffic-based framework for measuring the resilience of ground transportation systems under normal and extreme conditions. The research methodology consisted of: (1) creating a microscopic traffic model of the road under study, (2) simulating different intrusions and interventions, and (3) measuring the resilience of the system under the different scenarios using the framework developed. This research expanded the current definition of infrastructure resilience, which includes the assessment of system performance versus time, to add a third dimension of resilience for ground transportation system's applications, namely: location. This third dimension considers how the system changes along the different locations in the network, which reflects more accurately the continuous behavior of a ground transportation network. The framework was tested in a 24 km segment of Interstate 95 in Virginia, near Washington, D.C. Four hazard conditions were simulated: inadequate base capacity, traffic incidents, work zones, and weather events. Intervention strategies tested include ramp meters and the use of the shoulder lane during extreme events. Public policy was also considered as a powerful intervention strategy. The findings of this research shed light over the current and future resilience of ground transportation systems when subject to multiple hazards, and the effects of implementing potential interventions. / Ph. D. / Ground transportation systems are essential for the mobility of people, goods and services. Thus, making sure these systems are <i>resilient</i> to the impact of natural and manmade disasters has become a top priority for engineers and policy makers. Disaster resilience is defined as the ability of a system to withstand the impact of a disaster and recover as quickly as possible. One of the major obstacles for increasing the resilience of ground transportation systems is the lack of a measuring framework. Such measuring framework is critical for identifying needs, monitoring changes, assessing improvements, and performing cost-benefit analysis. This research addresses this problem by developing a traffic-based framework for measuring the resilience of ground transportation systems under normal and extreme conditions. The research methodology consisted of: (1) creating a microscopic traffic model of the road under study, (2) simulating multiple hazards and mitigation strategies, and (3) measuring the resilience of the system under the different scenarios using the framework developed. This research expanded the current definition of infrastructure resilience, which includes the assessment of system performance versus time, to add a third dimension of resilience for ground transportation system’s applications, namely: location. This third dimension considers how the system changes along the different locations in the network, which reflects the continuous behavior of a ground transportation network. The framework was tested in a 24 km segment of Interstate 95 in Virginia, near Washington, D.C. Four hazard conditions were simulated: inadequate base capacity, traffic incidents, work zones, and weather events. Intervention strategies tested include ramp meters and the use of shoulder lanes. Public policy was also considered as a powerful intervention strategy. The findings of this research shed light over the current and future resilience of ground transportation systems when subject to multiple hazards, and the effects of implementing potential interventions.

Thesis (Ph. D. in Civil Engineering)--University of California, Berkeley, 2006. / Cover title. "Fall 2006." Includes bibliographical references (leaves 292-300). Also available online.

Driver behaviour has become an important aspect of transport research and over the years a considerable number of car following models have been developed. However, many of these models do not accurately simulate actual driving behaviour due to a lack of suitable qualitative and quantitative data. Moreover, the inclusion of socioeconomic variables in the existing models to ascertain the effect on car following behaviour is lacking. This research underlines the need to further investigate driving behaviour and car following models and to develop techniques to provide a better understanding of driver-vehicle interactions during car following. It investigates data collection techniques and develop better techniques to enhance and improve the collection of microscopic driver behaviour and traffic flow data. This study developed a novel data collection technique which involved instrumenting a private vehicle with front and rear advanced radar sensors, both forward and rear facing video-audio recorders connected to GPS based time series speed and distance measurement devices, an in-vehicle computer logging vehicle speed and a CAN monitoring interface user program to provide real time monitoring and display of data. This system has been utilised to collect a more enhanced and reliable microscopic driver behaviour data in three consecutive vehicles movements which represents an improvement from previously used systems. Three different versions of the GHR car following model were produced for: car following car, truck following car and car following truck. Further analysis of the GHR model showed that in the case of car following car, car drivers responses to the lead car are more obviously stronger than in the case of truck following a car. A distance-based car following model and distance-based two-leader car following model that predict the safe following distance of following vehicles were developed to provide a better understanding of driver behaviour. An extension of these models to include gender, corridor (road) type and vehicle occupancy showed evidence of statistical significance of these variables on driver behaviour. A bus following model that predicts the “following distance” also has been calibrated to describe the interactions between a bus and a car within urban-rural driving conditions. In addition, data analysis showed that drivers were inconsistent with their driving behaviour and that there was variability in driving behaviour across the drivers observed in keeping a safe or desired following distance. This study provides a platform for a number of future research agendas including data collection techniques for collection of driver behaviour data; evaluation of different ITS technologies; impact assessment of ACC on driver safety and improvement of traffic microscopic simulation tools in order to strengthen their ability to simulate realistic transport problems for efficient and effective transportation systems.

Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 1980. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / by Li-Moon Wann. / M.S.

Vegetation growing on railway trackbeds and embankments present potential problems. The presence of vegetation threatens the safety of personnel inspecting the railway infrastructure. In addition vegetation growth clogs the ballast and results in inadequate track drainage which in turn could lead to the collapse of the railway embankment. Assessing vegetation within the realm of railway maintenance is mainly carried out manually by making visual inspections along the track. This is done either on-site or by watching videos recorded by maintenance vehicles mainly operated by the national railway administrative body. A need for the automated detection and characterisation of vegetation on railways (a subset of vegetation control/management) has been identified in collaboration with local railway maintenance subcontractors and Trafikverket, the Swedish Transport Administration (STA). The latter is responsible for long-term planning of the transport system for all types of traffic, aswell as for the building, operation and maintenance of public roads and railways. The purpose of this research project was to investigate how vegetation can be measured and quantified by human raters and how machine vision can automate the same process. Data were acquired at railway trackbeds and embankments during field measurement experiments. All field data (such as images) in this thesis work was acquired on operational, lightly trafficked railway tracks, mostly trafficked by goods trains. Data were also generated by letting (human) raters conduct visual estimates of plant cover and/or count the number of plants, either on-site or in-house by making visual estimates of the images acquired from the field experiments. Later, the degree of reliability of (human) raters' visual estimates were investigated and compared against machine vision algorithms. The overall results of the investigations involving human raters showed inconsistency in their estimates, and are therefore unreliable. As a result of the exploration of machine vision, computational methods and algorithms enabling automatic detection and characterisation of vegetation along railways were developed. The results achieved in the current work have shown that the use of image data for detecting vegetation is indeed possible and that such results could form the base for decisions regarding vegetation control. The performance of the machine vision algorithmwhich quantifies the vegetation cover was able to process 98% of the image data. Investigations of classifying plants from images were conducted in in order to recognise the specie. The classification rate accuracy was 95%. Objective measurements such as the ones proposed in thesis offers easy access to the measurements to all the involved parties and makes the subcontracting process easier i.e., both the subcontractors and the national railway administration are given the same reference framework concerning vegetation before signing a contract, which can then be crosschecked post maintenance. A very important issue which comes with an increasing ability to recognise species is the maintenance of biological diversity. Biological diversity along the trackbeds and embankments can be mapped, and maintained, through better and robust mo nitoring procedures. Continuously monitoring the state of vegetation along railways is highly recommended in order to identify a need for maintenance actions, and in addition to keep track of biodiversity. The computational methods or algorithms developed formthe foundation of an automatic inspection system capable of objectively supporting manual inspections, or replacing manual inspections.

The objective of this study is to set a methodology for the economic evaluation of high speed ground transportation systems. The main objective of this study is to establish a systematic framework, in order that planners can quickly understand and analyze the implications that different policies have on the life-cycle of the transportation system. The methodology is adaptable for different modes and also for different locations at which similar systems could be implemented. The mode under consideration here is that of Magnetically levitated vehicles and the study area is the Northeast corridor of the United States. The economic evaluation is based on a Systems Dynamics simulation model. The model incorporates socioeconomic parameters, trip generation, mode split, traffic engineering, economic parameters and elements of mass transportation. The interactions within these subsystems and between them are studied through various policy analysis which were conducted. The range of policy covers socioeconomic parameters, traffic strategies and economic parameters. Life cycle costs and revenues are the key performance indicators. Parameters such as elasticity values were assumed based on previous studies conducted in other locations. Revenues from fares is the only benefit considered for implementation of the new transportation system. The model has been developed so that it can be expanded so as to include various other benefits from maglev implementation. The model is highly flexible and can be used for a wide range of policy analysis. With regard to magnetic levitated transportation system it was found to be an economically feasible transportation alternative to solve the problems facing high speed inter-city travel. The life cycle costs of such a venture were found to be highly sensitive to the cost of power and the elasticity values associated with the trip generation model. / Master of Science

The current debate on transport policy in the UK is focused on the need for a sustainable transport system. Buses play a vital role in achieving this, as they are the most frequently used and most accessible mode of public transport. However, the literature shows that the delivery of sustainable transport policies is not producing the desired outcomes (Hull, 2009) and the application of such policies in real situations remains inconsistent. This is evident across the UK where there has been a decrease in bus patronage and bus mileage. To address this gap, the aim of this research is to identify why bus policies are not imple-mented successfully at a local level and to provide recommendations for implementation and decision making that will aid policy makers, local authority staff, regional transport partnerships, bus operating companies and other practitioners working within the field of transport. A mixed methodology was chosen for this research and is divided into three key stages to address the research problem. The first methodology included an online ques-tionnaire and 143 questionnaires were sent to all public transport officers in Great Britain. 80 surveys were returned giving a response rate of 56%. The second methodology in-cluded telephone interviews conducted with 10 of those public transport officers who responded to the questionnaire in order to elicit a deeper understanding of the results, which could not be achieved from the questionnaire results alone. Finally, the third meth-odology included four case studies on specific bus schemes within Great Britain. These case studies were the Quality Contract Scheme in Tyne and Wear, Fastlink Scheme in Glasgow, Bus Priority Scheme in Solihull and Smart Ticketing Scheme in Dundee. While the questionnaires and telephone interviews provide an overview of bus policy imple-mentation across Great Britain, the multiple case studies were required to investigate the topic in depth, thus identifying the greatest barriers to bus policy implementation. Analysis of the three sets of data is based on the application of a new decision support frame-work developed in this research. The findings in this thesis reveal that local authorities in Great Britain are under-performing in the implementation of bus policy due to the barriers they face. The greatest barriers to implementation include the lack of a policy document; the characteristics of the organisation; availability of resources; intra-organisation support and communication; economic, social and political environments; and opposition, conflict, and ambiguities. Overall, this research has identified several concerns with bus policy implementation. The most obvious concern is the unclear link between policy objectives and measures and the setting and monitoring of performance targets. Meanwhile, the deregulation of the bus sector in the UK means that, in some cases, a lack of control over the implementation of certain measures places limits on policy implementation and results in the frequent im-plementation of policy measures that are achievable rather than those that are necessary to the achievement of policy objectives. The findings from this research also help policy-makers and transport planners to predict what makes implementation successful and to address problems and issues through improved policies and regulations, as well as to an-ticipate and plan for likely barriers. Moreover, addressing these barriers can help tackle the decline in bus mileage and bus usage across Great Britain.