Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways

Detalhes bibliográficos
Autor(a) principal: António Lobo
Data de Publicação: 2013
Outros Autores: Carlos Rodrigues, António Couto
Tipo de documento: Artigo
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: https://hdl.handle.net/10216/85059
Resumo: Speed is a key performance measure in economic and environmental analyses of two-lane highways. Speed, combined with the percentage of time spent following, is also used in the assessment of level of service. Under free-flow conditions, the circulation of a given vehicle is not constrained by the presence of other vehicles, and the driver's speed choice reflects the driver's response to the geometric features of the road and roadside interference, as well as the driver's perception of risk. Many studies concerned with the effects of road characteristics, design features in particular, on vehicle speed have been conducted in several countries in recent decades. These studies have provided useful tools for modeling speed and evaluating alignment consistency. This paper presents an exponential free-flow speed model, applicable to both curves and tangents, developed for two-lane highways in Portugal. The variables included in the model are representative not only of the road element under consideration (curve or tangent) but also of the preceding road section and of the visual field downstream from the element. The results from this model are compared with other authors' results and with the guidelines in the Highway Capacity Manual 2010. In addition to the primary influence of the horizontal curvature on speed, the results show that other factors, such as the cross-sectional width, the density of access points, and the downstream visibility, are important.
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spelling Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane HighwaysEngenharia de infra-estruturas, Engenharia civilInfrastructures engineering, Civil engineeringSpeed is a key performance measure in economic and environmental analyses of two-lane highways. Speed, combined with the percentage of time spent following, is also used in the assessment of level of service. Under free-flow conditions, the circulation of a given vehicle is not constrained by the presence of other vehicles, and the driver's speed choice reflects the driver's response to the geometric features of the road and roadside interference, as well as the driver's perception of risk. Many studies concerned with the effects of road characteristics, design features in particular, on vehicle speed have been conducted in several countries in recent decades. These studies have provided useful tools for modeling speed and evaluating alignment consistency. This paper presents an exponential free-flow speed model, applicable to both curves and tangents, developed for two-lane highways in Portugal. The variables included in the model are representative not only of the road element under consideration (curve or tangent) but also of the preceding road section and of the visual field downstream from the element. The results from this model are compared with other authors' results and with the guidelines in the Highway Capacity Manual 2010. In addition to the primary influence of the horizontal curvature on speed, the results show that other factors, such as the cross-sectional width, the density of access points, and the downstream visibility, are important.20132013-01-01T00:00:00Zinfo:eu-repo/semantics/publishedVersioninfo:eu-repo/semantics/articleapplication/pdfhttps://hdl.handle.net/10216/85059eng10.3141/2348-02António LoboCarlos RodriguesAntónio Coutoinfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2023-11-29T13:19:39Zoai:repositorio-aberto.up.pt:10216/85059Portal AgregadorONGhttps://www.rcaap.pt/oai/openaireopendoar:71602024-03-19T23:38:32.996001Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways
title Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways
spellingShingle Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways
António Lobo
Engenharia de infra-estruturas, Engenharia civil
Infrastructures engineering, Civil engineering
title_short Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways
title_full Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways
title_fullStr Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways
title_full_unstemmed Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways
title_sort Free-Flow Speed Model Based on Portuguese Roadway Design Features for Two-Lane Highways
author António Lobo
author_facet António Lobo
Carlos Rodrigues
António Couto
author_role author
author2 Carlos Rodrigues
António Couto
author2_role author
author
dc.contributor.author.fl_str_mv António Lobo
Carlos Rodrigues
António Couto
dc.subject.por.fl_str_mv Engenharia de infra-estruturas, Engenharia civil
Infrastructures engineering, Civil engineering
topic Engenharia de infra-estruturas, Engenharia civil
Infrastructures engineering, Civil engineering
description Speed is a key performance measure in economic and environmental analyses of two-lane highways. Speed, combined with the percentage of time spent following, is also used in the assessment of level of service. Under free-flow conditions, the circulation of a given vehicle is not constrained by the presence of other vehicles, and the driver's speed choice reflects the driver's response to the geometric features of the road and roadside interference, as well as the driver's perception of risk. Many studies concerned with the effects of road characteristics, design features in particular, on vehicle speed have been conducted in several countries in recent decades. These studies have provided useful tools for modeling speed and evaluating alignment consistency. This paper presents an exponential free-flow speed model, applicable to both curves and tangents, developed for two-lane highways in Portugal. The variables included in the model are representative not only of the road element under consideration (curve or tangent) but also of the preceding road section and of the visual field downstream from the element. The results from this model are compared with other authors' results and with the guidelines in the Highway Capacity Manual 2010. In addition to the primary influence of the horizontal curvature on speed, the results show that other factors, such as the cross-sectional width, the density of access points, and the downstream visibility, are important.
publishDate 2013
dc.date.none.fl_str_mv 2013
2013-01-01T00:00:00Z
dc.type.status.fl_str_mv info:eu-repo/semantics/publishedVersion
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status_str publishedVersion
dc.identifier.uri.fl_str_mv https://hdl.handle.net/10216/85059
url https://hdl.handle.net/10216/85059
dc.language.iso.fl_str_mv eng
language eng
dc.relation.none.fl_str_mv 10.3141/2348-02
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dc.source.none.fl_str_mv reponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron:RCAAP
instname_str Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
instacron_str RCAAP
institution RCAAP
reponame_str Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
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