Thesis (M.S.)--Ohio University, March, 1994. / Title from PDF t.p.

Thesis (M.S.)--Ohio University, March, 1998. / Title from PDF t.p.

Thesis (M.S.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains viii, 86, 82 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 85-86).

Thesis (M.S.)--Ohio University, March, 1999. / Title from PDF t.p.

Thesis (Ph. D.)--University of Rhode Island, 2004. / Typescript. Includes bibliographical references (leaves 233-243).

Thesis (MBA)--Stellenbosch University, 2013. / ENGLISH ABSTRACT: The study involved a detail empirical investigation into the different road studs in use on South Africa’s national road network and how they performed on the network under different road conditions in order to establish which road stud, under what conditions, offers best value for money in terms of life-cycle cost for the South African National Roads Agency Limited. These main questions were asked: What is the most cost-effective/value-for-money stud option for SANRAL to choose for each of the specified road categories? Under which conditions do the studs perform differently and what is the most likely mode of failure of specific studs linked to a specific road condition and road category? The South African and Australian road stud standards were reviewed to gain understanding of which criteria one has to consider when evaluating road studs and what information would be needed for the research. Similar studies on road studs were reviewed to compare the criteria that were looked at, namely Guidelines for the use of Raised Pavement Markers, developed by the Department of Transport in the United States, and Feasibility of using accelerated pavement testing to evaluate the long term performance of raised pavement markers, a research paper by the Florida Department of Transport. This research made use of a standardised questionnaire containing questions on various elements found to be key to the road stud performance. The study was done on approximately 4 659 km of roads in SANRAL’s Western region, consisting of the Western Cape and Northern Cape. From the literature review, it was identified that there is a need for the SABS standards to be updated to include the testing of structural properties of studs. SANRAL should look at the lack in specification requirements when asking for the installation of road studs. From the data available it was observed that the preferred studs were the Ferro Lynx followed by the STA+52 stud. They are predominantly used on the roads that were included in the survey. They perform well on the national roads. The data suggests that these two studs and the Rhino stud are the best-performing studs with the least dislodgement and loss in reflectivity. The STA+52 and Rhino stud, however, are fairly new on the market and more data for theirs full life cycle should be obtained for further monitoring The regression analysis indicated that 36 per cent of the variation in the reflectivity of the Ferro Lynx stud can be explained by the surface width of the road, the traffic volume measured as ELVS and the period installed. All the coefficients were significant with a 5 per cent significance. The prediction tables on the weighted data set, indicated that one should always consider width of road when choosing a road stud and that the reflectivity of studs deteriorates most on the narrower roads.

No description available.

Este trabalho visa propor um sistema consorciado para a manutenção da sinalização urbana em municípios de pequeno porte. A viabilidade do uso do consórcio foi verificada através da análise comparativa de custos e da carga operacional de uma central de atendimento para todas as cidades e da instalação de um centro de serviços em cada cidade. Um sistema de informações geográficas (TransCAD) foi usado para simular dois cenários: o serviço de manutenção a partir de uma central que atende todas as cidades versus um centro de atendimento em cada cidade. A viabilidade do uso do consórcio intermunicipal proposto é demonstrada através de um estudo de caso compreendendo 18 cidades na região central do estado de São Paulo. Os resultados finais mostram que os objetivos iniciais propostos foram alcançados. / The objective of this research was to propose the use, by small towns, of intercity consortia for the maintenance of traffic signs and road markings at urban intersections. The comparison was made in terms of total costs and operational load for a central service center, as opposed to the costs and operational loads of service centers located in each town. A geographical information system (TransCAD) was used to simulate two scenarios: maintenance services from a central location, serving all participating towns versus the use of a service center in each town. The feasibility of the proposed approach was demonstrated by a case study for 18 towns in the central region of the state of São Paulo. The final results prove that the initial objectives were achieved.

Este trabalho visa propor um sistema consorciado para a manutenção da sinalização urbana em municípios de pequeno porte. A viabilidade do uso do consórcio foi verificada através da análise comparativa de custos e da carga operacional de uma central de atendimento para todas as cidades e da instalação de um centro de serviços em cada cidade. Um sistema de informações geográficas (TransCAD) foi usado para simular dois cenários: o serviço de manutenção a partir de uma central que atende todas as cidades versus um centro de atendimento em cada cidade. A viabilidade do uso do consórcio intermunicipal proposto é demonstrada através de um estudo de caso compreendendo 18 cidades na região central do estado de São Paulo. Os resultados finais mostram que os objetivos iniciais propostos foram alcançados. / The objective of this research was to propose the use, by small towns, of intercity consortia for the maintenance of traffic signs and road markings at urban intersections. The comparison was made in terms of total costs and operational load for a central service center, as opposed to the costs and operational loads of service centers located in each town. A geographical information system (TransCAD) was used to simulate two scenarios: maintenance services from a central location, serving all participating towns versus the use of a service center in each town. The feasibility of the proposed approach was demonstrated by a case study for 18 towns in the central region of the state of São Paulo. The final results prove that the initial objectives were achieved.

<p>A complete prototype system for measuring vehicle lateral position has been set up during the course of this master’s thesis project. In the development of the software, images acquired from a back-ward looking video camera mounted on the roof of the vehicle were used. </p><p>The problem of using computer vision to measure lateral position can be divided into road marking detection and lateral position extraction. Since the strongest characteristic of a road marking image are the edges of the road markings, the road marking detection step is based on edge detection. For the detection of the straight edge lines a Hough based method was chosen. Due to peak spreading in Hough space, the difficulty of detecting the correct peak in Hough space was encountered. A flexible Hough peak detection algorithm was developed based on an adaptive window that takes peak spreading into account. The road marking candidate found by the system is verified before the lateral position data is generated. A good performance of the road marking tracking algorithm was obtained by exploiting temporal correlation to update a search region within the image. A camera calibration made the extraction of real-world lateral position information and yaw angle data possible. </p><p>This vision-based method proved to be very accurate. The standard deviation of the error in the position detection is 0.012 m within an operating range of ±2 m from the image centre. During continuous road markings the rate of valid data is on average 96 %, whereas it drops to around 56 % for sections with intermittent road markings. The system performs well during lane change manoeuvres, which is an indication that the system tracks the correct road marking. This prototype system is a robust and automatic measurement system, which will benefit VTI in its many driving behaviour research programs.</p>