6 results on '"Guardrails"'
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2. Impact on driver behaviour of guardrails of different height in horizontal-vertical coordinated road scenarios with a limited available sight distance.
- Author
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Lioi, A., Hazoor, A., Castro, M., and Bassani, M.
- Subjects
- *
RURAL roads , *GUARDRAILS on roads , *ROADSIDE improvement - Abstract
• Traffic barriers are hard protection systems that also affect driver sight along curves. • The use of higher guardrails with respect to minimum standards should be carefully evaluated. • Guardrail height impacts on lateral and longitudinal driver behaviour. • The higher the barrier, the outermost the trajectories. • Male and female drivers behave differently, with males travelling at higher speeds than females. Drivers consider traffic barriers (e.g., guardrails) a protection system, a hard obstacle and a sight obstruction. Hence, the possibility of using containment level barriers which are higher and superior than the minimum required by current standards should be carefully evaluated. Moreover, research investigations into their impact on driver behaviour should be designed so as to distinguish between the effects associated with each of the three roles cited above. This driving simulation study investigates how drivers adapt their longitudinal and transversal behaviour when negotiating curves with guardrails of different heights on horizontal-vertical coordinated two–lane rural road settings, with consideration given solely to the sight obstruction effect of the guardrails. Fifty-four participants drove four out of the eighteen possible scenarios obtained when the same horizontal alignment is combined with three vertical profiles with three inner roadside treatments (no guardrails, 0.75 m two–wave and 0.95 m three-wave guardrails) and the two driving directions. Research outcomes confirm that guardrail height has a significant impact on lateral and longitudinal behaviour. With the minimum standard, i.e., the minimum height, drivers stay closer to the roadside, while higher guardrails result in drivers increasing their lateral distance. Speeds are influenced by the interaction between the guardrail and other geometric and human factors. Male and female drivers adapt differently to the limitation in the available sight distance caused by the guardrail: males increase their speed, adopting a more aggressive behaviour than females. Important safety implications due to the higher speeds and wider trajectories have to be considered at the design stage. [ABSTRACT FROM AUTHOR] more...
- Published
- 2022
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3. Development of MASH TL-2 Crashworthy W-Beam Terminals For Low-Speed/Volume Roads
- Abstract
The objective of this research was to design a simple low-cost guardrail terminal at Manual for Assessing Safety Hardware (MASH) Test Level 2 (TL-2) (44 mi/h) that assumed use of a current generic MGS W-beam guardrail, which is the most widely used guardrail in the country. The terminal design was tested and evaluated according to the safety-performance evaluation guidelines included in the second edition of MASH (1). The crash tests were performed in accordance with MASH TL-2. This report provides details on the development and simulations of different designs for the TL-2 W-beam end terminal, the crash tests and results, and the performance assessment of the TL-2 W-beam end terminal for MASH TL-2 gating terminal evaluation criteria. The final TL-2 W-beam end terminal design met the performance criteria for MASH Tests 2-35, 2-30, 2-31, and 2-37b for gating terminals. more...
- Published
- 2023
4. Cost-Benefit Analysis for Concrete vs. Metal Guardrails and Wood vs. Metal Posts for Signs and Guardrails
- Published
- 2023
5. Modelação numérica do comportamento de barreiras de segurança rodoviária a ensaios de impacto de acordo com a norma EN 1317
- Author
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Serra, Luís Miguel Oliveira, Dourado, N., and Universidade do Minho
- Subjects
Finite element method ,Standard EN 1317 ,Guardrails ,Impact analysis ,Engenharia e Tecnologia::Engenharia Mecânica ,Norma EN 1317 ,Análise do impacto ,Barreiras de segurança ,Método dos elementos finitos - Abstract
Dissertação de mestrado integrado em Engenharia Mecânica, A segurança rodoviária é fortemente dependente não só dos veículos circulantes, mas também dos dispositivos mecânicos existentes nas estradas. Assim, a avaliação do comportamento mecânico dos equipamentos de segurança rodoviária constitui uma tarefa de grande importância, que merece a atenção da Academia. Um exemplo destes equipamentos corresponde às barreiras de segurança rodoviária, dispostas junto às bermas das faixas de rodagem, sendo sua principal função a contenção das mais variadas tipologias de veículos, em caso de despiste. Este conjunto mecânico é categorizado segundo diferentes níveis de contenção que oferece, estando relacionados com diferentes graus de deformabilidade. Estes devem ser capazes não só de reter e redirecionar o veículo para a faixa de rodagem, mas também de assegurar que o evento não seja nem demasiado brusco, nem associado a desacelerações abruptas, de modo a não proporcionar danos corporais aos condutores e acompanhantes. Neste contexto, surge o método dos elementos finitos, que constitui uma ferramenta bastante útil tanto no projeto, como no desenvolvimento e avaliação de novas soluções construtivas, pelo que a sua utilização será fundamental no processo associado ao cumprimento dos níveis de desempenho exigidos pela legislação existente. Esta dissertação visa desenvolver modelos numéricos capazes de avaliar mecanicamente dois modelos de barreira de segurança rodoviária desenvolvidos para os níveis de contenção N2W2 e N2W3, aquando de um evento relacionado com o impacto de um veículo, definido de acordo com a normalização em vigor no nosso país. Estes eventos encontram-se dependentes de parâmetros relacionados com o tipo de veículo, com a sua velocidade de circulação, o ângulo de incidência da trajetória, entre outros, pelo que os ensaios utilizados na sua homologação deverão respeitar diretrizes estabelecidas pela norma EN 1317. Neste documento, para além da avaliação do comportamento mecânico dos conjuntos referidos, bem como do acordo numérico-experimental para os modelos de prumo analisados, foi ainda desenvolvido um estudo referente à interação destes componentes com vários tipos de solos. Posto isto, a partir dos modelos desenvolvidos, foram extraídos resultados relativos ao deslocamento máximo obtido na barreira, em resultado do impacto do veículo, sugerindo que nenhum dos modelos projetados (propostos pela empresa Metalogalva S.A.) permite alcançar o nível de contenção proposto, de acordo com as condições de certificação impostas pela norma EN 1317., Road safety is strongly dependent not only on the vehicles in circulation but also on the mechanical devices present on the roads. Therefore, assessing road safety mechanisms is a relevant task, that deserves Academy attention. An example of these mechanisms corresponds to road safety barriers, included on the sides of the carriageway, where their main function is to contain the most varied types of vehicles. This mechanical assembly is categorised according to different levels of containment related to different degrees of deformability. These must be able not only to retain and redirect the vehicle to the carriageway but also to ensure that this phenomenon is neither too abrupt, nor associated with sudden decelerations, so as not to provide bodily harm to drivers. The finite element method concerns a handy tool in the design, development and evaluation of new constructive solutions, so its use will be fundamental in the process associated with achieving the objectives. This dissertation aims to develop numerical models capable of mechanically evaluating two sets of road safety barriers, developed for containment levels N2W2 and N2W3, at the time of an impact event defined according to the indicated standardisation used in our country. These events depend on parameters related to the type of vehicle, its speed of movement, its angle of impact, among other things, so the tests used in their approval must comply with these guidelines. In this document, in addition to the mechanical assessment of the road safety barriers and the numerical-experimental agreement for the analysed prop models, a study concerning the interaction of these components with various types of soils was also conducted. After the development of the numerical models, the results of the maximum displacement obtained in the barrier at the end of the simulated event were extracted and they suggest that none of the models designed (proposed by Metalogalva S.A. company) for the proposed level of containment fully complied with the certification conditions imposed by the standard., Este trabalho teve o apoio da ANI – Agência Nacional de Inovação, através do projeto com a referência COMPETE-2020/03/SI/2017 Nº033497, intitulado “Barreiras de segurança rodoviária”, com acrónimo “BarRod”, através do Programa Operacional Competitividade e Internacionalização e o Programa Operacional Regional de Lisboa, apoiada pelo FEDER. more...
- Published
- 2022
6. Impact on driver behaviour of guardrails of different height in horizontal-vertical coordinated road scenarios with a limited available sight distance
- Author
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A. Lioi, A. Hazoor, M. Castro, and M. Bassani
- Subjects
Available sight distance ,Driving simulation ,Guardrails ,Driver behaviour ,Design decision ,Automotive Engineering ,Transportation ,Applied Psychology ,Civil and Structural Engineering - Published
- 2022
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