liu.seSök publikationer i DiVA
Ändra sökning
Avgränsa sökresultatet
1 - 3 av 3
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Pérez Castro, Guillermo
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. Swedish National Road and Transport Research Institute (VTI).
    Johansson, Fredrik
    Swedish National Road and Transport Research Institute (VTI).
    Olstam, Johan
    Swedish National Road and Transport Research Institute (VTI).
    A Power-Based Approach to Model the Impact of Gradient in Bicycle Traffic Simulation2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    To simulate bicycle traffic accurately, it is essential to capture how bicyclists react to features of the infrastructure such as the longitudinal gradient of a bicycle path. Bicycling requires human-powered motion, and the power output provided by bicyclists differ significantly among bicyclists due to physical capabilities and preferences. Therefore, the objective of this paper is to investigate the connection between power output and gradient in bicycle traffic, with the purpose of developing a power-based model that predicts accurately the speed of bicyclists. Based on trajectory data of free-riding bicyclists travelling on a non-flat bicycle path segment, we estimate changes in power output as a function of gradient considering the physical forces acting on a bicycle. The results suggest a linear correlation between power output and gradient; while bicyclists increase their power output on the uphill as gradient increases, they decrease their power output on the downhill as gradient increases. By implementing this correlation into a traffic simulation algorithm, we show that the simulation captures well the impact of gradients in a population of bicyclists as it reproduces similar speed profiles. We conclude that bicyclists adapt their power output to compensate for the gradient and its associated change in speed, and that the impact of gradient varies greatly among bicyclists. Furthermore, we conclude that power-based modelling of free-riding bicyclists is an attractive alternative to investigate further.

  • 2. Beställ onlineKöp publikationen >>
    Pérez Castro, Guillermo
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Towards microscopic models for bicycle traffic simulation2023Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    As bicycling becomes an integral part of sustainable mobility, it becomes essential to enhance planning strategies that ensure bicycling as an efficient mode of transport. While traffic simulation has been extensively utilized for traffic planning of various modes of transport, this type of modeling support is largely lacking in the planning of bicycle traffic.

    Given the high heterogeneity in the characteristics of bicyclists, the use of microscopic traffic simulation, which incorporates the explicit inclusion of individual properties and preferences, becomes particularly useful for evaluating bicycle traffic performance.

    By examining real-world traffic, the objective of this thesis is to investigate essential requirements for microscopic modeling and simulation of bicycle traffic on off-street bicycle path segments, and to further develop and evaluate modeling approaches suitable for bicycle traffic. Understanding the fundamentals of how bicyclists interact with the infrastructure and other bicyclists is a necessary step towards accurate simulation of bicycle traffic.

    In this thesis, research gaps related to the evaluation of bicycle traffic performance and simulation are identified, and methods to validate bicycling data are proposed to determine its quality and suitability for traffic analysis. Furthermore, two distinct modeling approaches are investigated to simulate the impact of gradients in bicycle traffic. The first involves calibrating a car-based model using a widely-used microscopic traffic simulation software, and the second implements a power-based model rooted in the physical forces acting on a bicycle. Lastly, characteristics of bicycle traffic that are relevant for simulating bidirectional traffic are identified and described.

    The work in this thesis offers a starting point towards enhanced microscopic bicycle traffic simulation that effectively assist the planning of efficient bicycle traffic.

    Delarbeten
    1. How to Model the Effect of Gradient on Bicycle Traffic in Microscopic Traffic Simulation
    Öppna denna publikation i ny flik eller fönster >>How to Model the Effect of Gradient on Bicycle Traffic in Microscopic Traffic Simulation
    2022 (Engelska)Ingår i: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, Vol. 2676, nr 11, s. 609-620, artikel-id 03611981221094300Artikel i tidskrift (Refereegranskat) Published
    Abstract [en]

    Microscopic traffic simulation is a useful tool for the planning of motorized traffic, yet bicycle traffic still lacks this type of modeling support. Nonetheless, certain microscopic traffic simulators, such as Vissim, model bicycle traffic by applying models originally designed for car traffic. The gradient of a bicycle path has a significant impact on the speed of cyclists; therefore, this impact should be captured in microscopic traffic simulation. We investigate two calibration approaches to reproduce the effect of gradient on the speed of cyclists using the default driver behavioral model in Vissim. The first approach is to modify the simulated gradient to represent different values of the gradient-acceleration parameter: a fixed value that represents a decrease in the maximum acceleration that cyclists can apply on an uphill. The second approach is to adjust the maximum-acceleration function. We evaluate both approaches by applying a Vissim model of a bidirectional bicycle path with a 3% gradient in Stockholm. The results show that the current default implementation in the Vissim model underestimates the effect of gradient on speed. Moreover, the gradient-acceleration parameter does not directly reduce the maximum acceleration of all cyclists, but only of those cyclists riding above a certain speed. We conclude that by using a higher gradient-acceleration value than the default, we accurately estimate the observed mean speed on the uphill. However, neither of the investigated calibration approaches provides accurate estimates of the speed distributions. We emphasize the need for developing more accurate behavioral models designed for cyclists.

    Ort, förlag, år, upplaga, sidor
    Sage Publications Inc, 2022
    Nyckelord
    bicycle traffic and behavior; bicycle infrastructure design; gradient; speed; calibration; microscopic traffic simulation; Vissim
    Nationell ämneskategori
    Transportteknik och logistik
    Identifikatorer
    urn:nbn:se:liu:diva-186509 (URN)10.1177/03611981221094300 (DOI)000810319600001 ()
    Anmärkning

    Funding Agencies|Swedish Transport Administration (Trafikverket) via Centre for Traffic Research (CTR) [TRV 2019/84465]

    Tillgänglig från: 2022-06-29 Skapad: 2022-06-29 Senast uppdaterad: 2023-07-03Bibliografiskt granskad
    Ladda ner fulltext (pdf)
    fulltext
    Ladda ner (png)
    presentationsbild
  • 3.
    Perez Castro, Guillermo
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. Swedish Natl Rd & Transport Res Inst VTI, Linkoping, Sweden.
    Johansson, Fredrik
    Swedish Natl Rd & Transport Res Inst VTI, Sweden.
    Olstam, Johan
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. Swedish Natl Rd & Transport Res Inst VTI, Linkoping, Sweden.
    How to Model the Effect of Gradient on Bicycle Traffic in Microscopic Traffic Simulation2022Ingår i: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, Vol. 2676, nr 11, s. 609-620, artikel-id 03611981221094300Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Microscopic traffic simulation is a useful tool for the planning of motorized traffic, yet bicycle traffic still lacks this type of modeling support. Nonetheless, certain microscopic traffic simulators, such as Vissim, model bicycle traffic by applying models originally designed for car traffic. The gradient of a bicycle path has a significant impact on the speed of cyclists; therefore, this impact should be captured in microscopic traffic simulation. We investigate two calibration approaches to reproduce the effect of gradient on the speed of cyclists using the default driver behavioral model in Vissim. The first approach is to modify the simulated gradient to represent different values of the gradient-acceleration parameter: a fixed value that represents a decrease in the maximum acceleration that cyclists can apply on an uphill. The second approach is to adjust the maximum-acceleration function. We evaluate both approaches by applying a Vissim model of a bidirectional bicycle path with a 3% gradient in Stockholm. The results show that the current default implementation in the Vissim model underestimates the effect of gradient on speed. Moreover, the gradient-acceleration parameter does not directly reduce the maximum acceleration of all cyclists, but only of those cyclists riding above a certain speed. We conclude that by using a higher gradient-acceleration value than the default, we accurately estimate the observed mean speed on the uphill. However, neither of the investigated calibration approaches provides accurate estimates of the speed distributions. We emphasize the need for developing more accurate behavioral models designed for cyclists.

    Ladda ner fulltext (pdf)
    fulltext
1 - 3 av 3
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf