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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.
21

Analysing truck position data to study roundabout accident risk

Kamla, Jwan Jameel Shekh Mohammed January 2016 (has links)
In order to reduce accident risk, highway authorities prioritise maintenance budgets partly based upon previous accident history. However, as accident rates have continued to fall in most contexts, this approach has become problematic as accident ‘black spots’ have been treated and the number of accidents at any individual site has fallen. Another way of identifying sites of higher accident risk might be to identify near-miss accidents (where an accident nearly happened, but was avoided), which are likely to be much more prolific than actual accidents, therefore they are useful in identifying high-risk sites. The principal aim of this research is to analyse potentially unsafe truck driving conditions that involving harsh braking incidents (HBIs) that may indicate accident risk. Most modern truck fleets now record position as part of fleet management. This research used position data collected by a truck fleet management company for 8000 trucks in the United Kingdom (UK) over a 2-year period (2011-2012) to identify incidents of harsh braking. This data was compared with STATS19 accident data events (specifically truck accidents) occurring in 70 selected roundabouts (284 approaches) over an 11-year period (2002-2012), to test the hypothesis that the HBIs could represent accident near-misses and therefore increased accident risk. The data used for model prediction comprised all vehicle accidents, truck accidents, HBIs, geometric properties, and traffic characteristics for whole roundabouts, within the circulatory lanes, and at approaches to the selected roundabouts. Random-parameters negative binomial (NB) count data models were used to estimate model parameters and the models were compared with fixed-parameters NB count data models. It was found that random-parameters count data models provide better goodness of fit and more variables were found to be significant, giving a better prediction of events. It is concluded that HBIs are influenced by traffic and geometric variables in a similar way to total and truck accidents, therefore they may be useful in considering accident risk at roundabouts. They are a source of higher volumes of data than accidents, which is important in considering changes or trends in accident risk over a much shorter time. The most important variables were Average Annual Daily Traffic (AADT) and percentage of truck traffic, which were found to have a positive influence on accidents and HBIs. Regarding the geometric variables, signalisation, circulatory roadway width, number of arms and two-lane indicator were the most important factors influencing accidents and HBIs. In addition to these models, numbers of HBIs was used as an independent variable in the models of total and truck accidents, along with traffic and geometric variables. From the results it can be concluded that at all approaches, HBIs are related to total accidents along with traffic and geometric variables, which can be used to study safety measures. A good predictive model for truck accidents at M-class approaches based on HBI, traffic and geometric parameters was identified that can be used for prioritising safety at these approaches in order to make roundabouts safer. For A- and B-class approaches a better fit model were identified when HBI were used as input variable along with traffic and geometric variables compared to the model without using HBI as input variable, but the influence of HBIs was negative (high HBIs with low numbers of accidents) which is probably an indicator of future accident risk in these locations. For at-grade roundabouts, a better fit model was obtained for total and truck accidents when it is compared to the model without HBIs, but the influence of HBIs was negative; this is probably an indicator of high accident risks in these at-grade roundabouts, however further investigation is required with more observations. These results for truck HBIs could help highway authorities to identify sites of increased accident risk more rapidly and without waiting for an accident history to develop.
22

Upwardly mobile : private transport, regeneration and environment in the Thames Gateway

Lucas, Karen January 1998 (has links)
The thesis presents case study research into private vehicle use as it relates to the process of regeneration in the Thames Gateway. In doing so, it investigates two key contemporary transport policy issues. The first is the burgeoning debate surrounding the nature and extent of the relationship between transport investment and economic activity. Secondly, it explores the ways and means of encouraging more environmentally sustainable and equitable forms and levels of personal mobility. It argues that, in their present form, regeneration strategies will undermine attempts to promote and implement sustainable transport policies in the area. Part One of the thesis is a review of the theoretical literature and central government policy that focuses on the role of transportation in the regeneration process. It explores the implications of the new sustainability agenda for private car use against the background of the Thames Gateway. It concludes that the Thames Gateway offers both the physical opportunity for, and the legislative will to plan land use and transport together in an integrated manner. It recognises that the strategy needs to be capable of supporting the increased need for accessibility which regeneration requires, whilst simultaneously reducing many of the negative impacts of unfettered use of the private car. The chapter identifies a number of potential constraints on the realisation of such an approach at the delivery stage. Part Two presents the findings of the first stage of the empirical research. Through an analysis of local plans and proposals and interviews with key actors, it investigates the extent to which centrally defined policy is being adopted and applied at the local point of delivery. It finds that, despite incorporation of the rhetoric of sustainability within local development plans, fundamental contradictions in terms of the principles of sustainability exist within the transport policy statements of some authorities. Furthermore, sustainable policy aims, as they relate to planning the location and transportation needs of new developments, are often not applied in practice. Part Three assesses the implications of the current transport strategy on private car use in the Thames Gateway for future sustainability targets. It uses the data collected through the research from a local travel survey of car users, currently resident in the Thames Gateway area, to make projections for future car use in the context of a regenerated scenario, developed according to the present land use and transport policy framework. Future levels of CO2 emissions arising from private vehicle use are estimated on the basis of current car use, identified within the survey sample population and proportionately extrapolated to the wider population. These are set against the wider context of national figures for CO2 emissions and internationally binding government agreements to reduce these by the year 2005. On the basis of the evidence presented, the research concludes that the projected levels of CO2 emissions arising from increased private vehicle use in the Thames Gateway, as a outcome of the regeneration process and based on a 'do nothing' transport policy scenario, run counter to the principles of sustainability.
23

A study of individual travel behaviour in Edinburgh, to assess the propensity to use non-motorised modes

Ryley, Timothy John January 2005 (has links)
No description available.
24

Taxi licensing, regulation and control : an analysis of taxi supply in medium sized UK cities

Cooper, James Michael January 2007 (has links)
The primary objective of this thesis is to provide a new approach to optimizing the supply of taxis as applied in UK cities. Taxi supply, both in the UK and elsewhere, is controlled by a series of regulations (defined in relation to controls affecting Quantity, Quality and Economics - QQE) that influence the ability of the market to respond structurally - in terms of access to the market, and operationally - affecting the ability to provide services within the market. This thesis identifies the existing structures in taxi regulation. It explores legislative disagreement and differences in both academic and practitioner literature and perspectives. The thesis provides both a new approach to, and a new model of, taxi regulation, which accommodates existing differences in regulatory structures. The thesis builds on existing methods applied in determining individual elements of control - which may be appropriate to some elements of control but fail to address a full cross section of impacts - and provides an enhanced approach and new modelling framework for taxi regulation. In constructing this approach use has been made of both survey and case study methodologies. Survey data has been collected from two surveys, of 52 cities and 21 licensing authorities respectively. The case studies used are of Glasgow! and West Dunbartonshire(2). The thesis concludes that existing approaches to regulation are conducted in separate regulatory domains without sufficient comprehension of the impacts of action in one regulatory domain on another. It also concludes that the instruments used in the assessment of the impacts of regulation on taxi supply are insufficiently specified and inadequately coordinated. It is possible to identify issues across regulatory domains that can be improved to better optimize supply appropriate in any given circumstance to the benefit of existing and potential passengers - this includes those with particular access needs. In optimizing supply, awareness of the needs of the taxi industry and its regulators has been an important element of consideration. The thesis makes recommendations for alterations in the application of standard methods of assessment of taxi supply. 1 Although central to the Strathclyde conurbation, the Glasgow licensing area relates to the central city area only (Clydebank, Paisley, etc. being included in separate council licensing areas). The city is thus defined as medium sized location. 2 Further focus city material bas been collected from Belfast and Edinburgh, which is included in comparison within the text, and summarised in the appendices of this document.
25

Future of interactive technologies

Mohammed, Nadia January 2011 (has links)
The concept of interactivity continuously enhances our day-to-day living, allowing us to experience a more convenient and enjoyable life style. Existing analogue technologies such as the internet, mobile phone and satellite have now entered their digital phase, making it possible to increase their capacity for interactivity. The technologies which provide this increased interactivity, namely the internet, mobile and television, are classed as interactive technologies. Television has been successful at marketing, having launched an interactivity interface known as iTV which initially offered superior commercial prospects. However, after a decade, the iTV industry is still quite young and has not reached its full potential. This thesis adopts a range of research methodology with which to forecast the future of interactive technologies, especially interactive TV (iTV). The uptake of new interactive technologies depends on many factors, notably the existing infrastructure in the country of adoption, cultural attitudes to new technology, the radicalism of the technology, social influences and interactions and ease of use, quality and cost. Beyond these, many other significant factors influence the acceptance of interactive technologies, the focus of this thesis is to ascertain the importance of those factors mentioned on technology adoption. This study has adopted technological and judgemental forecasting techniques to predict the future of interactive technologies, following which Cross- Cultural and Technology Acceptance studies were carried out to investigate interactive technology adoption. In the Cross-Cultural study, survey data were collected from the UK, Hong Kong and Pakistan so as to examine cultural factors pertaining to the likelihood of adoption, while Growth Curves were used to model and forecast future levels of adoption. Then technology trends in different countries were collected from the global marketing database Euromonitor. The Growth Curves, applied to a selection of interactive technologies, were evaluated and compared to identify the most useful model with which to forecast the future of interactive technologies. The findings identified the Bass Model, Simple Logistic Model and Gompertz Model as the most suitable models for the purpose, with different models identified as best for different cultures. The Judgemental study established that WWW will be the dominant service provider for financial services such as banking or financial products, while iTV will be the dominant service provider for entertainment. WWW will in fact be the dominant provider for most of the services, followed by iTV and then WAP. It is most likely that WWW, WAP and iTV will exhibit technology convergence in 20 years' time and in all probability will converge into WWW. Further to this the Cross-Cultural study confirmed that there are significant differences between cultures regarding the acceptance of interactive technologies, as it is affected by demographic and social interactions and influences. In addition, the study showed that each interactive technology has its own significant elements which influence its acceptance. Overall, the key elements identified as influencing acceptance of interactive technologies were Knowledge and Confidence, followed by the number of hours the individual spends with his or her family. The Technology Acceptance study identified a technology acceptance model for each interactive technology: WWW, WAP and iTV, which established the factors expected to influence the future growth of the technology. Managing these significant elements will assist further in promoting the growth of interactive technologies
26

The governance of Libyan ports : determining a framework for successful devolution

Ghashat, Hesham January 2012 (has links)
Following a period of isolation, and particularly since the lifting of sanctions imposed by the United Nations at the beginning of the 1990s in 2003, Libya's economy has witnessed a remarkable growth with a corresponding increase in external trade. The country's economic policy has changed and become more liberalised; involving a move towards a market economy, an increase in the participation of the private sector in all economic activities, and diversification of the sources of national income. At the port sector level Libya aims to rehabilitate and modernise the container port sector, in order to cope with the technological development that has occurred in the global shipping and port industry. The future of the sector will also involve moving beyond serving the local trade; there is a desire to convert one or more of country's ports into a hub in the Mediterranean region, and as a gateway serving the trade oflandlocked countries. Many researchers have suggested that to handle changes in the operational environments at the ports the structure of the port should be an organic one in order to secure port responsiveness. Organic structure can be achieved via implementation of a devolution policy, and over the past two decades, devolution of port governance has proved to be one way of enhancing the efficiency of ports and of handling port authorities/governments strategy shifts. Furthermore; thus far changes in governance structure, via the implementation of devolution policy, have assisted in resolving port problems, which include physical, management and administration. This research contributes significantly to the literature in the field of ports' studies; offering the policy makers of Libya with a guide for the best way to govern the port sector in Libya and outlining the steps that need to be followed to achieve this. To achieve this, the thesis reviews the policy of port devolution, and the current situation within Libya's port industry in detail; discussing the challenges' facing the Libyan port sector (container and general cargo ports). Empirically, the necessity for the devolution of Libya's ports is examined with a matching framework analysis and this is further demonstrated via a stakeholders' attitudinal survey, including suggestions for the best future governance structure and the expected impact of adopting a devolution policy. The findings are validated using a Delphi survey; the technique was utilised to deduce the critical determinants for the successful implementation of a port devolution policy in Libya. The findings reveal that in order to help the sector to survive in the existing competitive environment, the technical performance of Libya's ports needs to be improved. A fundamental change to the governance structure of the sector is perceived as a top priority for enhancing its performance; the results confirm that the allocation of responsibility for port functions does not fall neatly into the categories proposed in the widely-accepted port privatisation matrix, and is instead subject to different factors, e.g. the country's financial capabilities. A further contribution is that stakeholder interests were used as a basis for measuring the performance of the new governance structure. The analysis indicates that changes in port governance structure are widely expected to have a positive impact, leading to benefits for the majority of port stakeholders. However, the success of the devolution policy was found to be determined by factors beyond the selection of an appropriate governance structure and stakeholder satisfaction; some of the success factors identified relate to the institutional environment of the port sector. By combining the findings of the primary surveys with the literature, a systematic integrated vision for the success of port devolution in Libya is proposed.
27

The role of logistical structure in the development of rail freight services in Great Britain

Woodburn, Allan G. January 2000 (has links)
Modal shift from road to rail for freight movements is a potential means by which the negative environmental and social impacts of such transport can be reduced. As such it features strongly in contemporary transport policies in Great Britain. This thesis examines the interactions between logistical structure and freight modal choice, to determine the extent to which rail's mode share is likely to be increased. The research assesses the influence of recent logistical changes both within companies and along supply chains on mode choice and identifies the likelihood of future changes resulting in greater rail usage. A combined approach involving a postal questionnaire survey and in-depth company interviews was adopted. Further, to consider the interactions between the supply of rail freight services and their level of uptake, original databases of rail freight services at the disaggregated level have been constructed and analysed for the years 1991, 1997, 1998, 1999 and 2000. The research thus provides a greater understanding of the importance of modal choice in individual firms' logistical decision-making processes, as well as through supply chains from source to customer. Key logistical issues that have affected, and are likely to affect, mode choice are identified and utilised to assess the potential for rail. Significant potential for modal shift is found to exist though many obstacles are also identified for many types of movement, relating to both supply- and demand-side factors. The importance of a coherent transport policy to deal with these obstacles to allow rail freight to meet its potential is highlighted.
28

Traffic and road sign recognition

Fleyeh, Hasan January 2008 (has links)
This thesis presents a system to recognise and classify road and traffic signs for the purpose of developing an inventory of them which could assist the highway engineers' tasks of updating and maintaining them. It uses images taken by a camera from a moving vehicle. The system is based on three major stages: colour segmentation, recognition, and classification. Four colour segmentation algorithms are developed and tested. They are a shadow and highlight invariant, a dynamic threshold, a modification of de la Escalera's algorithm and a Fuzzy colour segmentation algorithm. All algorithms are tested using hundreds of images and the shadow-highlight invariant algorithm is eventually chosen as the best performer. This is because it is immune to shadows and highlights. It is also robust as it was tested in different lighting conditions, weather conditions, and times of the day., Approximately 97% successful segmentation rate was achieved using this algorithm. Recognition of traffic signs is carried out using a fuzzy shape recogniser. Based on four shape measures - the rectangularity, triangularity, ellipticity, and octagonality, fuzzy rules were developed to determine the shape of the sign. Among these shape measures octangonality has been introduced in this research. The final decision of the recogniser is based on the combination of both the colour and shape of the sign. The recogniser was tested in a variety of testing conditions giving an overall performance of approximately 88%. Classification was undertaken using a Support Vector Machine (SVM) classifier. The classification is carried out in two stages: rim's shape classification followed by the classification of interior of the sign. The classifier was trained and tested using binary images in addition to five different types of moments which are Geometric moments, Zernike moments, Legendre moments, Orthogonal Fourier-Mellin Moments, and Binary Haar features. The performance of the SVM was tested using different features, kernels, SVM types, SVM parameters, and moment's orders. The average classification rate achieved is about 97%. Binary images show the best testing results followed by Legendre moments. Linear kernel gives the best testing results followed by RBF. C-SVM shows very good performance, but v-SVM gives better results in some case.
29

Pedestrian right-of-way violations at signalised pedestrian crossings in Edinburgh

Alnaqbi, Khalfan Saeed January 2013 (has links)
The review of available literature related to pedestrian accidents indicates that the occurrence of pedestrian accidents is influenced by a diverse range of factors. However, few empirical studies have documented the effects of distance of pedestrian accidents from pedestrian crossing area or junction. The few studies which investigated the impact of the distance from the crossing line on pedestrian accidents, suggest that the longer the distance from road crossing facilities, the higher the likelihood of a pedestrian accident. With respect to the influence of the type of pedestrian crossing on the incidence of pedestrian accidents, a substantial body of literature has found that the types of pedestrian crossing indeed affect the frequency of pedestrian collisions. Additionally, all the available studies reviewed indicated the positive impact of signalised crossings on the reduction of pedestrian collision risk. Data from STATS19 show that pedestrian severity rates are higher over the pedestrian crossing points or within 50 meters of pedestrian crossing facilities than those away from it. This is contrary to the expectations that accidents should be least over these crossing facilities. This study investigates in more detail the factors that affect accident occurrence at signalised pedestrian junction and pelican or similar type of crossing facilities in the Scotland area. The main objective of this current research has been to investigate those factors most commonly associated with pedestrian injury severity at a pedestrian crossing or within 50m of one. Accident data of 14 years (from 1993 until 2006) in selected sites show that 942 pedestrian accidents occurred on or within 50m of a signalised pedestrian crossing area. Grid references of accident locations as well as locations of pedestrian crossings were obtained from the STATS 19 database and the local city council. The data was used to identify the locations of accidents relative to the location of pedestrian crossing facilities. In terms of severity of injuries models, results suggest that pedestrians from the older group received more severe injuries, compared with those from younger groups. Again, this finding underlines the importance of regulations and subsequent enforcement of traffic laws that protect and promote the safety of older pedestrians. The models also showed an association between the severity of injury and the type of pedestrian crossing. Since more KSI accidents have been associated with pelican crossings, there may be a need to undertake raising awareness and education for pedestrians to improve pedestrian safety. In terms of ROW models; it was shown that turning manoeuvres were more likely to violate pedestrian's ROW and result in accidents than other types of manoeuvres. Moreover, the model showed that heavy-goods vehicles and cars are associated with pedestrian's ROW, as compared to other types of vehicles. The various issues related to accidents resulting from pedestrian right-of-way can be effectively resolved by rationalisation of pedestrian crossing types; and provision of education with regards to the rules and responsibilities of both pedestrians and drivers at all available crossings. The models developed to profile pedestrian accidents in Edinburgh suggest that the highest number of pedestrian accidents occurred at pedestrian crossing lines; and that the number of pedestrian accidents decreased when moving away from pedestrian crossing lines or within 50 metres of pedestrian crossing lines. These have serious implications in terms of requiring improvements to pedestrian crossing facilities that can then ensure better pedestrian visibility and provide the public with more protection from moving vehicles. Moreover, another implication of this finding is that more regulatory instruments must be revalidated and further developed, since there are no laws to prevent pedestrians from crossing the road at certain points. The only laws being enforced in the UK are those relating to the prohibition of walking on motorways or slip roads but not regarding loitering on pedestrian crossings. Therefore, the guidelines specified in the Highway Code to deal with pedestrian behaviour while crossing the road have to be revisited and further developed. The results show that accidents rates decrease as distance increase from the pedestrian crossing facilities. The most risky locations are those at the pedestrian crossings or within 10 meters and the distance from 10 to 30 meters before the pedestrian crossing facilities. Analysis of pedestrian accidents rates and severities for each of pelican and signalised crossings were discussed. An investigation of right-of-way violations associated with pedestrian accidents at pedestrian crossing areas or within 50 metres of the same was carried out. Modelling accidents rates and severities at these pedestrian crossings is also presented in this thesis. Multinomial logit, ordinal and probit logit and binary logit modelling are used to analyse the results.
30

Investigation of driving cycles as tools to assess travel demand management in Edinburgh and Abu Dhabi

Al Zaidi, Ahmed January 2013 (has links)
Traffic congestion today is a major problem in almost all of the metropolitan areas of the world. An increasing level of congestion results in negative impacts on the urban environment. These include environmental pollution, energy problems and traffic accidents. The analysis of these problems and the predictions of the impacts of any transport policies that could be devised to deal with them are very critical to their success. Traffic problems are almost the same in most modern cities either in developed countries or less economically developed countries. The driving cycle for a vehicle is the representation of a speed–time sequenced profile, which is developed for a specific area or city. It is an important requirement in the evaluation of the driver's behaviour and the performance of vehicles for a number of applications, mainly in the area of environmental studies. For example, fuel consumption and emissions' predictions need information input on the characteristics of driving patterns of traffic. The applications of driving cycle analysis can be extended however, to many more other areas. The motivation for this research is to investigate the detailed impacts of travel demand management (TDM) measures, that are already in application. This is to improve the network performance, using driving cycle analysis. It is important to explicitly assess these measures using a micro-level detailed approach in order to comprehend overall results in terms of emissions and network performance. These understandings will benefit government agencies and policy makers in their planning and appraisals. It will also benefit public transport providers to improve their service in attracting and retaining their customers. The developments of the real world driving cycles in Edinburgh and Abu Dhabi have been presented in this research. The analysis of real world data, which has been obtained from monitoring traffic conditions in both cities using the GPS tracking of traffic, is presented. This data was collected from trips which have been carried out on a number of traffic corridors in both cities. The assessment of various parameters of traffic (i.e. speed, time percentage spent on acceleration, deceleration, idling, cruising and cycle duration) and their statistical validity, produced a real world driving cycle for the buses as well as the private cars. Two TDM measures have been considered; bus lanes and traffic calming measures. At each corridor, a handheld GPS device was used to record speed, acceleration, deceleration and distances driven. This data enabled the analysis of driving cycles for the buses and for the private cars. The driving cycle analysis and investigations have further been investigated using regression analysis techniques. The results suggest that the approach shows potential but further research is needed with more data available. The results suggest that the driving cycle analysis approach would be very useful to have a better understanding of driving behaviour and also the detailed impacts of the transport policies on traffic. In terms of bus lanes and traffic calming measures, the results show some positive impacts of these policies, while there are evidences of some negative impacts as well. These findings would be very valuable for the policy decision makers. It is recommended from this research that the driving cycle analysis could be utilised effectively in the assessment of TDM measures. Further investigations and analysis of driving cycle is urgently recommended in a number of research directions. Combined GIS and GPS data could also enhance the development in this research.

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