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  • 1.
    Allström, Andreas
    et al.
    Trivector .
    Olstam, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Thorsson, Tobias
    WSP .
    Analys av modeller för beräkning av framkomlighet i korsningar2008Report (Other academic)
  • 2.
    Aria, Erfan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, Faculty of Science & Engineering.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Swedish National Rd and Transport Research Institute VTI, Linkoping, Sweden.
    Schwietering, Christoph
    Schwietering Traff Engineers, Germany.
    Investigation of Automated Vehicle Effects on Drivers Behavior and Traffic Performance2016In: INTERNATIONAL SYMPOSIUM ON ENHANCING HIGHWAY PERFORMANCE (ISEHP), (7TH INTERNATIONAL SYMPOSIUM ON HIGHWAY CAPACITY AND QUALITY OF SERVICE, 3RD INTERNATIONAL SYMPOSIUM ON FREEWAY AND TOLLWAY OPERATIONS), ELSEVIER SCIENCE BV , 2016, Vol. 15, p. 761-770Conference paper (Refereed)
    Abstract [en]

    Advanced Driver Assistance Systems (ADAS) offer the possibility of helping drivers to fulfill their driving tasks. Automated vehicles (AV) are capable of communicating with surrounding vehicles (V2V) and infrastructure (V2I) in order to collect and provide essential information about the driving environment. Studies have proved that automated driving have the potential to decrease traffic congestion by reducing the time headway (THW), enhancing the traffic capacity and improving the safety margins in car following. Despite different encouraging factors, automated driving raise some concerns such as possible loss of situation awareness, overreliance on automation and system failure. This paper aims to investigate the effects of AV on drivers behavior and traffic performance. A literature review was conducted to examine the AV effects on drivers behavior. Findings from the literature survey reveal that conventional vehicles (CV), i.e. human driven, which are driving close to a platoon of AV with short THW, tend to reduce their THW and spend more time under their critical THW. Additionally, driving highly AV reduce situation awareness and can intensify driver drowsiness, exclusively in light traffic. In order to investigate the influences of AV on traffic performance, a simulation case study consisting of a 100% AV scenario and a 100% CV scenario was performed using microscopic traffic simulation. Outputs of this simulation study reveal that the positive effects of AV on roads are especially highlighted when the network is crowded (e.g. peak hours). This can definitely count as a constructive point for the future of road networks with higher demands. In details, average density of autobahn segment remarkably improved by 8.09% during p.m. peak hours in the AV scenario, while the average travel speed enhanced relatively by 8.48%. As a consequent, the average travel time improved by 9.00% in the AV scenario. The outcome of this study jointly with the previous driving simulator studies illustrates a successful practice of microscopic traffic simulation to investigate the effects of AV. However, further development of the microscopic traffic simulation models are required and further investigations of mixed traffic situation with AV and CV need to be conducted.

  • 3.
    Bergh, Torsten
    et al.
    Swedish Transport Adm, Sweden; Movea Trafikkonsult, Sweden.
    Remgard, Mats
    Swedish Transport Adm, Sweden.
    Carlsson, Arne
    Swedish National Rd and Transport Research Institute, Linköping, Sweden.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Swedish National Road and Transport Research Institute, Linköping, Sweden.
    Strömgren, Per
    Movea Trafikkonsult, Sweden.
    2+1-roads Recent Swedish Capacity and Level-of-Service Experience2016In: INTERNATIONAL SYMPOSIUM ON ENHANCING HIGHWAY PERFORMANCE (ISEHP), (7TH INTERNATIONAL SYMPOSIUM ON HIGHWAY CAPACITY AND QUALITY OF SERVICE, 3RD INTERNATIONAL SYMPOSIUM ON FREEWAY AND TOLLWAY OPERATIONS), ELSEVIER SCIENCE BV , 2016, Vol. 15, p. 331-345Conference paper (Refereed)
    Abstract [en]

    The first Swedish 2+1 median barrier road was opened in 1998. The concept was to retrofit the standard existing two-lane 13 m paved width cross-section at 90 and 110 kph posted speed limit without widening. This design has one continuous lane in each direction, a middle lane changing direction every one to three kilometres with a median barrier separating the two traffic directions. Today over 2 700 km 2+1 median barrier roads are opened for traffic. AADTs vary from some 3 000 to 20 000 with an average just below 10 000 nowadays normally with 100 kph. The concept has lately been enhanced also to cover the existing 9 m paved width cross-section. The design concept is the same from a drivers viewpoint, one continuous lane in each direction with a middle lane changing direction and a separating median barrier. This is created by introducing a continuous median barrier and adding overtaking lanes within an overtaking strategy. The differences are the existence of 1+1-sections, less overtaking opportunities and a slightly more narrow cross-section. Some 15 projects are opened. The purpose of this paper is to summarize present knowledge on level-of-service issues as they are presented in Swedish design and assessment guidelines and to give an overview of field measurements and theoretical analytical and simulation studies supporting the recommendations.

  • 4.
    Bergman, Astrid
    et al.
    Trivector Traffic, Lund, Sweden.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Allström, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Analytical traffic models for roundabouts with pedestrian crossings2011Conference paper (Refereed)
    Abstract [en]

    Roundabouts have become a more common type of intersection in Sweden over the last 30 years. In order to evaluate the roundabout level-of-service both analytical models and simulation models are being used. Analytical traffic models for intersections, such as the Swedish capacity model Capcal, has difficulties estimating the level-of-service of a roundabout if there are pedestrians and cyclists at crossings located close to the roundabout. It is well known that a crossing located after a roundabout exit can cause an up-stream blocking effect that affects the performance of the roundabout. But how the upstream blocking effect depends on the different flows of vehicles and pedestrians is not known. In this paper an existing analytical model by Rodegerdts and Blackwelder has been investigated and compared to simulations in VISSIM and measurements from Swedish roundabouts. The purpose of this investigation is to examine if the model by Rodegerdts and Blackwelder is suitable for implementing into existing analytical models such as Capcal. The results show that the model by Rodegerdts and Blackwelder can estimate if a capacity loss will occur, but the magnitude of this loss is more difficult to evaluate. The conclusion and recommendation is that the model by Rodegerdts and Blackwelder should be implemented into the Swedish capacity model Capcal. The model by Rodegerdts and Blackwelder is to be used as a warning system if the results in Capcal are too uncertain to use for analysis of the roundabout performance.

  • 5.
    Bernhardsson, Viktor
    et al.
    Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Trafikanalys och logistik, TAL.
    Olstam, Johan
    Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Trafikanalys och logistik, TAL.
    Effektiva omkörningsfält på 2+1-vägar: trafiksimuleringar av olika utformningsalternativ ur ett framkomlighetsperspektiv2017Report (Other academic)
    Abstract [en]

    The traffic performance at oncoming lane separated highways with alternating dedicated overtaking lanes (so called 2+1 roads), is dependent on the share of two lane segments (also known as the share of overtaking length). In order to maximize utilization and traffic performance, the configuration of the overtaking lanes should be designed to avoid congestion and delays. Short overtaking lanes implies limited time of queue discharge, but gives frequently recurring possibilities to overtake. Increased lengths of overtaking lanes imply the possibility to overtake several vehicles per overtaking lane, but increases the risk of catching up slower vehicles since the configuration also results in increased lengths of one lane segments.

    This report presents a traffic simulation study of how different configurations affects the throughput at 2+1 roads. The results indicate that overtaking lanes between 1 050 and 1 400 meters result in shortest travel time. However, the differences are small (~0.4 seconds/km) and not statistically significant. Thus, the benefit of optimizing the configuration in terms of throughput could be questioned. Based on the results, it becomes reasonable to question the concept of designing 2+1 roads with long overtaking lengths (which corresponds to the recommendations from the Swedish Transport Administration (Trafikverket)). The major risk of catching up a slower vehicle at the one lane segments obviously affects the travel time.

  • 6.
    Bång, Karl-Lennart
    et al.
    Kungliga Tekniska Högskolan, KTH, Stockhollm.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Köhler, Joakim
    WSP, Parsons Brinckerhoff, UK.
    Wahlstedt, Johan
    Kungliga Tekniska Högskolan, KTH, Stockholm.
    Andersson, Jonas
    Tyréns AB, Stockholm.
    Handbok för kapacitetsanalys med hjälp av simulering2014Report (Other academic)
    Abstract [sv]

    Syftet med föreliggande handbok är att beskriva hur trafiksimulering kananvändas som en alternativ metod eller komplement till analytiska metoderför att bestämma kapacitet och framkomlighet. Liksom metodbeskrivningarnai TRV2013/64343 är beskrivningarna avsedda att kunna användas för att medhjälp av trafiksimulering uppskatta effekterna av en given utformning isamband med planering, konsekvensanalys, projektering och drift avvägtrafikanläggningar. Simulering kan användas som ett komplement till deanalytiska metoderna, eller som ersättning i fall som inte täcks av dessametoder. Härigenom minskas risken för onödiga kostnader förorsakade avsåväl över- som underkapacitet.

  • 7.
    Bång, Karl-Lennart
    et al.
    Kungliga Tekniska Högskolan, KTH, Stockholm.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Köhler, Joakim
    WSP Sverige AB, Stockholm.
    Wahlstedt, Johan
    Kungliga Tekniska Högskolan, KTH, Stockholm.
    Andersson, Jonas
    Tyréns AB, Helsingborg .
    Tapani, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Handbok för kapacitetsanalys med hjälp av simulering2014Report (Other academic)
    Abstract [sv]

    Syftet med föreliggande handbok är att beskriva hur trafiksimulering kan användas som en alternativ metod eller komplement till analytiska metoder för att bestämma kapacitet och framkomlighet. Liksom metodbeskrivningarna i TRV2013/64343 är beskrivningarna avsedda att kunna användas för att med hjälp av trafiksimulering uppskatta effekterna av en given utformning i samband med planering, konsekvensanalys, projektering och drift av vägtrafikanläggningar. Simulering kan användas som ett komplement till de analytiska metoderna, eller som ersättning i fall som inte täcks av dessa metoder. Härigenom minskas risken för onödiga kostnader förorsakade av såväl över- som underkapacitet.

  • 8.
    Carlsson, Arne
    et al.
    Statens väg- och transportforskningsinstitut,, VTI.
    Wiklund, Mats
    Statens väg- och transportforskningsinstitut,, VTI.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Tapani, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Metod för beräkning av fördröjningar på vägavsnitt utan omkörningsmöjlighet2013Report (Other academic)
    Abstract [en]

    This VTI report presents a method for calculating expected queue length and travel timedelay on one lane road sections without overtaking possibilities. The method wasdeveloped 2001 and presented in a working paper. The background for the modeldevelopment was that the Swedish Road Administration (now the Swedish TransportAdministration) planned to build so called 1+1 roads, i.e. roads with longer sectionswithout overtaking possibilities. The method developed has later on also shown to bevaluable for level of service calculations of 2+1 roads with varying share of two lanesections and for developing speed-flow relationships for the Administration’s ”Effectcalculations for road facilities”.The method uses section length, traffic flow, average speed and standard deviation asinput. The method is divided with respect to calculation of effects due to single slowrunningvehicles and effects at “normal” speed distribution. Since no data wereavailable when the model was developed, the model results were instead compared totraffic simulations with the microscopic traffic simulation model AIMSUN. The resultsshow a good correlation but the analytical model gives in general approximately 1.2 percent lower travel time delay. The differences can probably partly be explained by thestochastic parts of the simulation model. One should also remember that neither theanalytical model nor the simulation model has been calibrated and validated with realdata for this type of roads. Thus, the differences between the models do not necessaryimply that the analytical model is the one deviating from reality.

  • 9.
    Elyasi-Pour, Roya
    et al.
    Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Utvärdering av förarstödsystem baserat på sammankoppling av trafiksimulering och fordonsimulering2014Conference paper (Other academic)
  • 10.
    Elyasi-Pour, Roya
    et al.
    Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Utvärdering av förarstödsystem baserat på sammankoppling av trafiksimulering och fordonsimulering2014Conference paper (Other academic)
  • 11.
    Gyergyay, Bernard
    et al.
    Rupprecht Consult Forschung & Beratung GmbH.
    Gomari, Syrus
    Rupprecht Consult Forschung & Beratung GmbH.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Johansson, Fredrik
    VTI.
    Friedrich, Markus
    University of Stuttgart, Institute for Road and Transport Science.
    Sonnleitner, Jörg
    University of Stuttgart, Institute for Road and Transport Science.
    Rupprecht, Siegfried
    Rupprecht Consult Forschung & Beratung GmbH.
    Backhaus, Wolfgang
    Rupprecht Consult Forschung & Beratung GmbH.
    Automation-ready framework for urban transport planning2018Other (Other academic)
    Abstract [en]

    The mission of the H2020 CoEXist project is to enable mobility stakeholders to get “Automation-ready” – which CoEXist currently defines as conducting transport and infrastructure planning for connected and automated vehicles (CAVs) in the same comprehensive manner as for existing modes such as conventional vehicles, public transport, pedestrians, and cyclists, while ensuring continued support for existing modes on the same network. This definition will be fine-tuned through stakeholder engagement processes. The H2020 CoEXist project started in May 2017 and will run until April 2020. This paper introduces this project and covers its progress until January 2018, with a focus on the methodology of the “Automation-ready framework” that provides a planning framework for urban road authorities to prepare for the introduction of CAVs on the road network. The framework includes elements about strategic urban mobility planning for CAVs and a clear guide for urban transport planners with a list of concrete actions that cities can do now to plan for CAVs on their road network

  • 12.
    Jonkers, Eline
    et al.
    TNO, The Hague, The Netherlands.
    Carsten, Oliver
    Institute for Transport Studies, Leeds, UK.
    Nellthorp, John
    Institute for Transport Studies, Leeds, UK.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Tapani, Andreas
    Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Data and framework for scaling up2014Report (Other academic)
    Abstract [en]

    The global aim of the ecoDriver project is to increase the fuel efficiency by 20% by optimising the driver-powertrain-environment feedback loop and delivering effective advice to drivers. In the course of the project, field experiments will take place with a wide range of vehicles — e.g. cars, light trucks and vans, medium and heavy trucks and buses — covering both individual and collective transport. The last step of the project (Sub Project 5; SP5) is to scale up the results from these tests and analyse costs and benefits for a number of futurescenarios.

    The aim of SP5 is to predict the impact of the ecoDriver systems and solutions in the future, drawing on all the evaluations carried out in the project. With the results of SP5 it will be possible to make estimates about the costs and benefits of the suggested green driving support systems on a global (EU-27) level, both for society as a whole and for sub-groups like manufacturers and consumers. SP5 will construct a set of possible scenarios for the future depending on various road maps envisioned today. The predictions for future years will be made based on available data from within and outside of the project, and on advanced microscopic traffic modelling. SP5 takes the following steps to meet the objectives:

    • Collect data needed for scaling up and developing scenarios
    • Create a range of scenarios
    • Assess the network implications of green driving support systems for future networks
    • Predict the global impacts for a range of systems and scenarios
    • Carry out a cost benefit analysis for a range of systems and scenarios

    This deliverable describes the data needs for each step. It also contains a description of the approaches proposed for the scenario building, the microscopic traffic simulations, the scaling up and the cost-benefit analysis.

  • 13.
    Olstam, Johan
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    A model for simulation and generation of surrounding vehicles in driving simulators2005Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Driving simulators are used to conduct experiments on for example driver behavior, road design, and vehicle characteristics. The results of the experiments often depend on the traffic conditions. One example is the evaluation of cellular phones and how they affect driving behavior. It is clear that the ability to use phones when driving depends on traffic intensity and composition, and that realistic experiments in driving simulators therefore has to include surrounding traffic.

    This thesis describes a model that generates and simulates surrounding vehicles for a driving simulator. The proposed model generates a traffic stream, corresponding to a given target flow and simulates realistic interactions between vehicles. The model is built on established techniques for time-driven microscopic simulation of traffic and uses an approach of only simulating the closest neighborhood of the driving simulator vehicle. In our model this closest neighborhood is divided into one inner region and two outer regions. Vehicles in the inner region are simulated according to advanced behavioral models while vehicles in the outer regions are updated according to a less time-consuming model. The presented work includes a new framework for generating and simulating vehicles within a moving area. It also includes the development of enhanced models for car-following and overtaking and a simple mesoscopic traffic model.

    The developed model has been integrated and tested within the VTI Driving simulator III. A driving simulator experiment has been performed in order to check if the participants observe the behavior of the simulated vehicles as realistic or not. The results were promising but they also indicated that enhancements could be made. The model has also been validated on the number of vehicles that catches up with the driving simulator vehicle and vice versa. The agreement is good for active and passive catch-ups on rural roads and for passive catch-ups on freeways, but less good for active catch-ups on freeways.

  • 14.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Beräkning av kapacitet och reshastighet på 2+1- och tvåfältsvägar2013Conference paper (Other academic)
  • 15.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Cirkulationsplatser2014In: TRVMB Kapacitet och framkomlighetseffekter: Trafikverkets metodbeskrivning för beräkning av kapacitet och framkomlighetseffekter i vägtrafikanläggningar / [ed] Freddie Westman, Borlänge: Trafikverket , 2014, TRV 2013:64343, p. 314-349Chapter in book (Other academic)
    Abstract [sv]

    Detta kapitel behandlar beräkning av kapacitet, fördröjning, andel stopp och kölängd för:

    • Cirkulationsplatser i 3- och 4-vägs korsningar med ett eller två cirkulerande körfält. Varierande antal cirkulerande körfält behandlasinte.
    • Metoderna kan dock relativt enkelt utökas för att behandla cirkulationsplatser med fler än fyra ben.

    Metoden behandlar också överbelastning enligt metodik i Trafikverkets Effektkatalog Bygga om och Bygga nytt (version april 2014). Förutsättning för överbelastning är att överbelastningen varar en timme med trafikflöde 0 efter denna timme. Metoden är implementerad i Capcal 4.0, (se Capcal 4.0 Användarhandledning Trivector2013:87).

    För varje delavsnitt finns kommentarer på vänster sida och beräkningsstegen på högersida. Dokumentet bör således läsas och skrivas ut dubbelsidigt för bästa läsbarhet.

    Definitioner i form av allmänna termer och beteckningar är dokumenterade i kapitel 1 avsnitt 1.7. och litteraturreferenser i avsnitt 1.8.

  • 16.
    Olstam, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Effekter av dedicerade körfält för tung trafik på flerfältsväg2004Report (Other academic)
  • 17.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Ej signalreglerade korsningar2014In: TRVMB Kapacitet och framkomlighetseffekter: Trafikverkets metodbeskrivning för beräkning av kapacitet och framkomlighetseffekter i vägtrafikanläggningar / [ed] Freddie Westman, Borlänge: Trafikverket , 2014, TRV 2013:64343, p. 271-313Chapter in book (Other academic)
    Abstract [sv]

    Detta kapitel behandlar beräkning av kapacitet, fördröjning, andel stopp och kölängd för:

    • 3- och 4-vägskorsningar med stopp- eller väjningsplikt förunderordnade tillfarter
    • Det finns även korrigeringar för beräkning av korsningar medhögerregel.

    Metoden behandlar också överbelastning enligt metodik i Trafikverkets Effektkatalog Bygga om och Bygga nytt (version april 2014). Förutsättning för överbelastning är att överbelastningen varar en timme med trafikflöde 0 efter denna timme. Metoden är implementerad i Capcal 4.0, (se Capcal 4.0 Användarhandledning Trivector2013:87).

    För varje delavsnitt finns kommentarer på vänster sida och beräkningsstegen på högersida. Dokumentet bör således läsas och skrivas ut dubbelsidigt för bästa läsbarhet.

    Defnitioner i form av allmänna termer och beteckningar är dokumenterade i kapitel 1 avsnitt 1.7. och litteraturreferenser i avsnitt 1.8.

  • 18.
    Olstam, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Generation and simulation of surrounding vehicles in a driving simulator2006In: Driving Simulator Conference,2006, 2006Conference paper (Other academic)
    Abstract [en]

      

  • 19.
    Olstam, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Harmonisering av hastigheter - Effekter av minskad hastighetsspridning2004Report (Other academic)
  • 20.
    Olstam, Johan
    Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Trafikanalys och logistik, TAL.
    Kalibrering av restidsfunktioner: förslag till metodik och datainsamlingsupplägg2017Report (Other academic)
    Abstract [en]

    Route choice calculations in static traffic assignment models (as Emme, Visum, TransCad) are based on travel time estimations using volume delay functions. The volume delay function (also denoted travel time functions) describe how the travel time depend on the traffic volume for different types of roads. The volume delay functions are one of the base elements in travel prognosis models as the Swedish Sampers model system. This report presents a pre-study with the aim to investigate how volume delay functions should be designed and calibrated, including which road classification to use, which type of volume delay function that should be used, how the functions should be calibrated and which data that is needed for the calibration. These questions were investigated by a literature review on state-of-practice, workshops with experienced Sampers users to collect information and experiences of the current volume delay functions in Sampers, workshops with research experts on data collection of travel times, and project internal discussions on calibration methodologies.

    The literature review showed that there are few guidelines on how volume delay functions can or should be calibrated. The calibration is commonly conducted by fitting the volume delay function curve to cross-sectional measurements of flow and mean speed. There are some examples of calibration based on travel time measurements based on floating car measurements or number plate recognition. These calibration approaches focus on describing travel time for a given link based on the flow at the link. However, based on the literature review and experience from earlier research in Sweden it is concluded that volume delay functions that represent the traffic process on a road link in a good way do not necessary give a good fit of the static assignment calculated and observed link and route flows and travel times. There are several attempts described in the literature of calibration approaches that aim to minimize the difference between model calculated and observed flows and travel times using optimization techniques. The suggestion from the pre-study is that such an approach should be investigated for calibration of the Sampers volume delay functions. To avoid overfitting and unrealistic parameters values the optimization should include lower and upper limits of the parameters.

    The calibration requires both link flow and travel time observations. Link counts are regularly measured for other purposes and can be collected from the Swedish Transport Administration and municipality regular traffic measurement programs. The suggestion for travel time data is to use the travel time data that currently is commissioned by the Swedish Transport Administration and Stockholm and Göteborg municipality. Our recommendation is also that the Swedish Transport Administration investigate the possibility to buy travel time data for the Swedish main road network.

  • 21.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Kapacitet i Landsbygd2014Conference paper (Other academic)
  • 22.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Kapacitet i landsbygd2014Conference paper (Other (popular science, discussion, etc.))
  • 23.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Landsvägar2014In: TRVMB Kapacitet och framkomlighetseffekter: Trafikverkets metodbeskrivning för beräkning av kapacitet och framkomlighetseffekter i vägtrafikanläggningar / [ed] Freddie Westman, Borlänge: Trafikverket , 2014, TRV 2013:64343, p. 42-91Chapter in book (Other academic)
    Abstract [sv]

    Kapitlet omfattar beräkning av kapacitet, belastningsgrad och reshastighet för personbilar (inkl. släp), lastbilar utan släp och lastbilar med släp för:

    • tvåfältig landsväg (tvåfält),
    • mötesfri motortrafikled (MML) med varierande andel omkörningsfältmellan 40 – 85 %,
    • mötesfri landsväg (MLV) med varierande andel omkörningsfält mellan 15 – 85 %,

    med hastighetsgräns 70 km/h eller högre.

    Med ömkörbar längd avses andel sträcka i en riktning som är två körfält inkluderat inledningssträckor och exkluderat avslutningssträckor.

    För MML med 100 % tvåfält, som innebär två genomgående körfält genom trafikplats, behandlas vägen som en fyrfältsväg (4 F) med motsvarande hastighetsgräns, hastighet och kapacitet, se Kapitel 2. Vid enbart ett genomgående körfält i trafikplats erhålls max 85 % omkörningsfält och övergången två till ett ger en väsentlig lägre kapacitet.

    Reshastighetsberäkningen avser förhållanden utan överbelastning. För överbelastade situationer anges samma schablonmetod som i Trafikverkets effektsamband (version april 2014).

    De geometri- och regleringsdata som ingår är andel omkörbarlängd (för mötesseparerad väg), hastighetsbegränsning och siktklass.

    Trafikflödesberoende data som behövs är trafikflöde, riktningsfördelning och andel tunga fordon. För tvåfältsvägar ingår vägbredd som indata medan för MML och MLV antas att:

    • MLV 15-30 % har en standardvägbredd på 8-12 m
    • MML/MLV 40 % har en standardvägbredd på 13-14 m
    • MML/MLV 60 % har en standardvägbredd på 13-17 m
    • MML/MLV 85 % har en standardvägbredd på 16-18 m,

    Beräkningsmetoden är en uppdatering av beräkningsmetoden i Effektsamband för transportsystemet Bygg om eller bygg nytt (Trafikverket, 2014 April; Carlsson, 2007). För varje delmoment finns kommentarer på vänster sida och beräkningsstegen på högersida. Dokumentet bör således läsas och skrivas ut dubbelsidigt för bästa läsbarhet.

    Definitioner omfattande allmänna termer och deras beteckningar är dokumenterade i kapitel 1 avsnitt 1.7.

    Litteraturreferenser inkluderande de som avser landsvägar är dokumenterade i kapitel 1 avsnitt 1.8

  • 24.
    Olstam, Johan
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Simulation of rural road traffic for driving simulators2005In: Proceedings of the 84th Annual meeting of the Transportation Research Board, Washington D.C., USA, 2005Conference paper (Other academic)
    Abstract [en]

    Driving simulators are used to conduct experiments on driver behavior, road design, and vehicle characteristics, etc. The results of the experiments often depend on traffic conditions. One example is the evaluation of cellular phones and how they affect driving behavior. It is clear that the ability to use phones when driving depends on traffic intensity and composition, and that realistic experiments in driving simulators must therefore include surrounding traffic. This paper describes a model that generates and simulates surrounding rural road tra±c for a driving simulator. The model generates a traffic stream, corresponding to a given target flow and simulates realistic interactions between vehicles. The model is built on established techniques for time-driven microsimulation of traffic. The model only considers the closest neighborhood of the driving simulator vehicle. This neighborhood is divided into one inner region and two outer regions. Vehicles in the inner region are simulated according to advanced behavioral models while vehicles in the outer regions are updated according to a less time-consuming model. The paper also discusses calibration and validation of the model and the problem of combining stochastic traffic and driving simulator scenarios.

  • 25.
    Olstam, Johan
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Simulation of Surrounding Vehicles in Driving Simulators2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Driving simulators and microscopic traffic simulation are important tools for making evaluations of driving and traffic. A driving simulator is de-signed to imitate real driving and is used to conduct experiments on driver behavior. Traffic simulation is commonly used to evaluate the quality of service of different infrastructure designs. This thesis considers a different application of traffic simulation, namely the simulation of surrounding vehicles in driving simulators.

    The surrounding traffic is one of several factors that influence a driver's mental load and ability to drive a vehicle. The representation of the surrounding vehicles in a driving simulator plays an important role in the striving to create an illusion of real driving. If the illusion of real driving is not good enough, there is an risk that drivers will behave differently than in real world driving, implying that the results and conclusions reached from simulations may not be transferable to real driving.

    This thesis has two main objectives. The first objective is to develop a model for generating and simulating autonomous surrounding vehicles in a driving simulator. The approach used by the model developed is to only simulate the closest area of the driving simulator vehicle. This area is divided into one inner region and two outer regions. Vehicles in the inner region are simulated according to a microscopic model which includes sub-models for driving behavior, while vehicles in the outer regions are updated according to a less time-consuming mesoscopic model.

    The second objective is to develop an algorithm for combining autonomous vehicles and controlled events. Driving simulators are often used to study situations that rarely occur in the real traffic system. In order to create the same situations for each subject, the behavior of the surrounding vehicles has traditionally been strictly controlled. This often leads to less realistic surrounding traffic. The algorithm developed makes it possible to use autonomous traffic between the predefined controlled situations, and thereby get both realistic traffc and controlled events. The model and the algorithm developed have been implemented and tested in the VTI driving simulator with promising results.

    List of papers
    1. Simulation of rural road traffic for driving simulators
    Open this publication in new window or tab >>Simulation of rural road traffic for driving simulators
    2005 (English)In: Proceedings of the 84th Annual meeting of the Transportation Research Board, Washington D.C., USA, 2005Conference paper, Published paper (Other academic)
    Abstract [en]

    Driving simulators are used to conduct experiments on driver behavior, road design, and vehicle characteristics, etc. The results of the experiments often depend on traffic conditions. One example is the evaluation of cellular phones and how they affect driving behavior. It is clear that the ability to use phones when driving depends on traffic intensity and composition, and that realistic experiments in driving simulators must therefore include surrounding traffic. This paper describes a model that generates and simulates surrounding rural road tra±c for a driving simulator. The model generates a traffic stream, corresponding to a given target flow and simulates realistic interactions between vehicles. The model is built on established techniques for time-driven microsimulation of traffic. The model only considers the closest neighborhood of the driving simulator vehicle. This neighborhood is divided into one inner region and two outer regions. Vehicles in the inner region are simulated according to advanced behavioral models while vehicles in the outer regions are updated according to a less time-consuming model. The paper also discusses calibration and validation of the model and the problem of combining stochastic traffic and driving simulator scenarios.

    Keywords
    traffic simulation, micro-simulation, driving simulators, behavior models
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17448 (URN)
    Available from: 2009-03-25 Created: 2009-03-25 Last updated: 2013-09-13Bibliographically approved
    2. A Framework for Simulation of Surrounding Vehicles in Driving Simulators
    Open this publication in new window or tab >>A Framework for Simulation of Surrounding Vehicles in Driving Simulators
    2008 (English)In: ACM Transactions on Modeling and Computer Simulation, ISSN 1049-3301, E-ISSN 1558-1195, Vol. 18, no 3Article in journal (Refereed) Published
    Abstract [en]

    This article describes a framework for generation and simulation of surrounding vehicles in a driving simulator. The proposed framework generates a traffic stream, corresponding to a given target flow and simulates realistic interactions between vehicles. The framework is based on an approach in which only a limited area around the driving simulator vehicle is simulated. This closest neighborhood is divided into one inner area and two outer areas. Vehicles in the inner area are simulated according to a microscopic simulation model including advanced submodels for driving behavior while vehicles in the outer areas are updated according to a less time-consuming mesoscopic simulation model. The presented work includes a new framework for generating and simulating vehicles within a moving area. It also includes the development of an enhanced model for overtakings and a simple mesoscopic traffic model. The framework has been validated on the number of vehicles that catch up with the driving simulator vehicle and vice versa. The agreement is good for active and passive catch-ups on rural roads and for passive catch-ups on freeways, but less good for active catch-ups on freeways. The reason for this seems to be deficiencies in the utilized lane-changing model. It has been verified that the framework is able to achieve the target flow and that there is a gain in computational time of using the outer areas. The framework has also been tested within the VTI Driving simulator III.

    Keywords
    Traffic simulation, behavior modeling, driving behavior, driving simulators, mesoscopic traffic simulation, microscopic traffic simulation, real-time simulation, traffic generation
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17449 (URN)10.1145/1371574.1371575 (DOI)
    Note
    © ACM, (2008). This is the author's version of the work. It is posted here by permission of ACM for your personal use. Not for redistribution. The definitive version is: Johan Janson Olstam, Jan Lundgren, Mikael Adlers and Pontus Matstoms, A Framework for Simulation of Surrounding Vehicles in Driving Simulators, 2008, ACM Transactions on Modeling and Computer Simulation, (18), 3, .http://dx.doi.org/10.1145/1371574.1371575Copyright: Association for Computing Machineryhttp://www.acm.org/Available from: 2009-03-27 Created: 2009-03-25 Last updated: 2017-12-13Bibliographically approved
    3. Combination of autonomous and controlled vehicles in driving simulator scenarios
    Open this publication in new window or tab >>Combination of autonomous and controlled vehicles in driving simulator scenarios
    2007 (English)In: Proceedings of Road Safety and Simulation (RSS2007), Rome, Italy, 2007Conference paper, Published paper (Other academic)
    Abstract [en]

    This paper presents a design methodology for driving simulator scenarios in which autonomous and controlled surrounding vehicles are combined. The main motives are to achieve both a high realism and high reproducibility. The methodology is introduced using a theater metaphor in which a driving simulator scenario is defined as a constellation of: everyday life driving, preparations for plays, and plays. Advantages, disadvantages and diffiulties with the proposed methodology are discussed.

    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17450 (URN)
    Available from: 2009-03-25 Created: 2009-03-25 Last updated: 2013-09-13Bibliographically approved
    4. An algorithm for combining autonomous vehicles and controlled events in driving simulator experiments
    Open this publication in new window or tab >>An algorithm for combining autonomous vehicles and controlled events in driving simulator experiments
    Show others...
    2011 (English)In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 19, no 6, p. 1185-1201Article in journal (Refereed) Published
    Abstract [en]

    Autonomous vehicles can be used to create realistic simulations of surrounding vehicles in driving simulators. However, the use of autonomous vehicles makes it difficult to ensure reproducibility between subjects. In this paper, an effort is made to solve the problem by combining autonomous vehicles and controlled events, denoted plays. The aim is to achieve the same initial play conditions for each subject, since the traffic situation around the subject will be dependant upon each subject's actions while driving in the autonomous traffic. This paper presents an algorithm that achieves the transition from autonomous traffic to a predefined start condition for a play. The algorithm has been tested in the VTI driving simulator III with promising results. In most of the cases the algorithm could reconstruct the specified start condition and conduct the transition from autonomous to controlled mode in a non-conspicuous way. Some problems were observed regarding moving unwanted vehicles away from the closest area around the simulator vehicle, and this part of the algorithm has to be enhanced. The experiment also showed that the controlled every-day life traffic normally used in the VTI driving simulator makes subjects drive faster than in autonomous traffic.

    Place, publisher, year, edition, pages
    Elsevier, 2011
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17451 (URN)10.1016/j.trc.2011.02.003 (DOI)000295663100018 ()
    Note
    Funding agencies|Swedish Road Administration, Transport Telematics Sweden||INRETS||Available from: 2009-03-25 Created: 2009-03-25 Last updated: 2017-12-13
    5. Enhancements to the Intelligent Driver Model
    Open this publication in new window or tab >>Enhancements to the Intelligent Driver Model
    2010 (English)In: TRB 89th annual meeting Compendium of Papers DVD, Washington D.C.: Transportation Research Board , 2010Conference paper, Published paper (Other academic)
    Abstract [en]

    This paper presents a modified version of the Intelligent Driver Model (IDM) [M. Treiber, A. Hennecke, and D. Helbing, Phys. Rev. E. 62, 2 (2000)]. The IDM is a car-following model. A car-following model controls the accelerations of individual vehicles in a microscopic traffic simulation model. The original IDM has been observed to result in negative vehicle accelerations in situations where the distance to the preceding vehicle is much larger than the estimated desired safety distance. In this paper, we propose a modified function for the interaction with preceding vehicles which do not include this model property. A comparison of the results of simulations with the original and the modified IDM shows that the modified IDM results in higher average speed for a specific flow, a less steep speed-flow relationship and higher capacity. The speed-flow relationships of simulations with the modified IDM are also shown to better match the speed-flow relationships in real traffic on Swedish freeways. The differences between the results for the original and the modified IDM increase if the models are extended to include drivers' anticipation of the downstream traffic condition.

    Place, publisher, year, edition, pages
    Washington D.C.: Transportation Research Board, 2010
    National Category
    Engineering and Technology
    Identifiers
    urn:nbn:se:liu:diva-17452 (URN)
    Conference
    Transportation Research Board 89th Annual Meeting
    Available from: 2009-03-25 Created: 2009-03-25 Last updated: 2014-11-28
  • 26.
    Olstam, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Simulation of traffic for driving simulators2006In: Transportforum,2006, Linköping: VTI , 2006Conference paper (Other academic)
  • 27.
    Olstam, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Simulation of vehicles in a driving simulator using microscopic traffic simulation2006In: International Symposium on Transport Simulation,2006, 2006Conference paper (Other academic)
    Abstract [en]

      

  • 28.
    Olstam, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Simulation of vehicles in a driving simulators using microscopic traffic simulation2009In: Transport Simulation - Beyond Traditional Approaches / [ed] Edward Chung and André-Gilles Dumont, Lausanne, Switzerland: EPFL Press , 2009, 1, p. 41-56Chapter in book (Other academic)
    Abstract [en]

      In recent years, the transport simulation of large road networks has become far more rapid and detailed, and many exciting developments in this field have emerged.  Within this volume, the authors describe the simulation of automobile, pedestrian, and rail traffic coupled to new applications, such as the embedding of traffic simulation into driving simulators, to give a more realistic environment of driver behavior surrounding the subject vehicle. New approaches to traffic simulation are described, including the hybrid mesoscopic-microscopic model and floor-field agent-based simulation. Written by an invited panel of experts, this book addresses students, engineers, and scholars, as well as anyone who needs a state-of-the-art overview of transport simulation today.

  • 29.
    Olstam, Johan
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Trafiksimulering i kombination med körsimulator2004In: Transportforum,2004, Linköping: VTI , 2004Conference paper (Other academic)
    Abstract [sv]

        

  • 30.
    Olstam, Johan
    et al.
    Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Trafikanalys och logistik, TAL..
    Bernhardsson, Viktor
    Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Trafikanalys och logistik, TAL..
    Hastighetsflödessamband för svenska typvägar: Förslag till reviderade samband baserat på trafikmätningar från 2012–20152017Report (Other academic)
    Abstract [en]

    Speed-flow relationships are an important part of the Swedish Transport Administration (Trafikverket) model for evaluation of effects of road facilities (the EVA model). This report present suggestions for new speed-flow relationships for motorways (MV), low standard motorways (4F), oncoming lane separated highways with grade separated intersections (MML), oncoming separated highways with at grade intersections (MLV), and two-lane highways. The suggestions are based on data from measurements using the Swedish Transport Administration’s traffic measurement system TMS in combination with model calculations. The TMS data have, for each road category, been quality checked, processed and analysed. The data material is presented as speed-flow diagrams for passenger cars, buses and trucks without trailer, and trucks with trailers. A comparison of the current speed-flow relationships and the TMS-measurements was then conducted for each road category, and if needed a suggestion for a revision was presented. The most significant changes from last revision from 2013 are: average free flow speed for trucks without trailer have in general increased for all road types except two lane highways for which the speed has decreased; average free flow speed for trucks with trailers have in general decreased; and the average speed on two lane highways have in general decreased

  • 31.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Carlsson, Arne
    Statens väg- och transportforskningsinstitut, Miljö och trafikanalys, MTA.
    Yahya, Mohammad Reza
    Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Hastighetsflödessamband för svenska typvägar: förslag till reviderade samband baserat på TMS-mätningar från 2009-20112013Report (Other academic)
    Abstract [en]

    This report presents suggestions for new speed-flow relationships for motorways (MV), low standard motorways (4F), oncoming lane separated highways with grade separated intersections (MML), oncoming lane separated highways with at grade intersections (MLV), and two-lane highways. The suggestions are based on measurements from Trafikverket’s traffic count measuring system TMS in combination with model calculations. The TMS data have, for each road category, been quality checked, processed and analyzed. The data material is presented as speed-flow graphs for personal cars, trucks/buses without trailers and trucks with trailers. A comparison of the current speed-flow relationships and the TMS measurements was then conducted for each road category. The revised set of relationships then constituted the base for the 2012 revision of Trafikverket's publication "Effect calculations for road facilities". The analysis conducted resulted in suggestions to decrease the free flow speed and the travel speed at higher flows for most of the road categories. For motorways also a decrease in capacity is suggested. For oncoming separated highways (both MML and MLV) are minor changes of the capacity suggested. The suggested capacity value is for MML and MLV 1550 vehicles/h independently of speed limit and lane/road width.

  • 32.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Elyasi-Pour, Roya
    Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Combining traffic and vehicle simulation for enhanced evaluations of powertrain related ADAS for trucks2013In: Proceedings of the 16th International IEEE Annual Conference on Intelligent Transportation Systems (ITSC 2013), The Hague, The Netherlands, October 6-9, 2013, IEEE, 2013, p. 851-856Conference paper (Refereed)
  • 33.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Statens väg- och transportforskningsinstitut, Samhälle, miljö och transporter, SAMT, Trafikanalys och logistik, TAL..
    Engelson, Leonid
    Trafikverket.
    Johansson, Lars
    Trafikverket.
    Rydergren, Clas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Nya restidsfunktioner med korsningsfördröjning2016Report (Other academic)
    Abstract [en]

    This report presents method and result for the development of new travel time functions for the Swedish national transport planning modelling system Sampers. Travel time functions include one part that describes the travel time delay on road links and one part that describes the delay at intersections. It is difficult and expensive to conduct synchronized measurements of traffic flow and travel times. An alternative approach has therefore been applied in which the travel time functions were calibrated based on calculations of intersection delay for different intersection designs using the intersection delay and capacity model Capcal. The travel time functions developed were tested and validated are now implemented in the Sampers system.

  • 34.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology.
    Espié, Stéephane
    INRETS, Institut National de REcherche sur les Transports et leur Séecurité, 2, Av. du Gl. Malleret-Joinville, F-94114, Arcueil, France.
    Combination of autonomous and controlled vehicles in driving simulator scenarios2007In: Proceedings of Road Safety and Simulation (RSS2007), Rome, Italy, 2007Conference paper (Other academic)
    Abstract [en]

    This paper presents a design methodology for driving simulator scenarios in which autonomous and controlled surrounding vehicles are combined. The main motives are to achieve both a high realism and high reproducibility. The methodology is introduced using a theater metaphor in which a driving simulator scenario is defined as a constellation of: everyday life driving, preparations for plays, and plays. Advantages, disadvantages and diffiulties with the proposed methodology are discussed.

  • 35.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Espié, Stéphane
    INRETS, Institut National de REcherche sur les Transports et leur Sécurité, 58, Bd Lefebvre F-75732 Paris, France.
    Combination of autonomous and controlled vehicles in driving simulator scenarios2010In: Advances in Transportation Studies, ISSN 1824-5463, Vol. 21, p. 23-32Article in journal (Refereed)
    Abstract [en]

    This paper presents a design methodology for driving simulator scenarios in which autonomous and controlled surrounding vehicles are combined. The main motives are to achieve both a high realism and high reproducibility. The methodology is introduced using a theater metaphor in which a driving simulator scenario is defined as a constellation of: everyday life driving, preparations for plays, and plays. Advantages, disadvantages and difficulties with the proposed methodology are discussed.

  • 36.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Espié, Stéphane
    INRETS.
    Combination of autonomous and controlled vehicles in driving simulator scenarios2008In: WORKSHOP ON TRAFFIC MODELING: TRAFFIC BEHAVIOR AND SIMULATION,2008, Graz: TU Graz , 2008Conference paper (Other academic)
  • 37.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Espié, Stéphane
    INRETS, Institut National de REcherche sur les Transports et leur Sécurité, 58, Bd Lefebvre F-75732 Paris, France.
    Mårdh, Selina
    Swedish National Road and Transport Research Institute (VTI), VTI, SE-581 95 Linköping, Sweden.
    Jansson, Jonas
    Swedish National Road and Transport Research Institute (VTI), VTI, SE-581 95 Linköping, Sweden .
    Lundgren, Jan
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    An algorithm for combining autonomous vehicles and controlled events in driving simulator experiments2011In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 19, no 6, p. 1185-1201Article in journal (Refereed)
    Abstract [en]

    Autonomous vehicles can be used to create realistic simulations of surrounding vehicles in driving simulators. However, the use of autonomous vehicles makes it difficult to ensure reproducibility between subjects. In this paper, an effort is made to solve the problem by combining autonomous vehicles and controlled events, denoted plays. The aim is to achieve the same initial play conditions for each subject, since the traffic situation around the subject will be dependant upon each subject's actions while driving in the autonomous traffic. This paper presents an algorithm that achieves the transition from autonomous traffic to a predefined start condition for a play. The algorithm has been tested in the VTI driving simulator III with promising results. In most of the cases the algorithm could reconstruct the specified start condition and conduct the transition from autonomous to controlled mode in a non-conspicuous way. Some problems were observed regarding moving unwanted vehicles away from the closest area around the simulator vehicle, and this part of the algorithm has to be enhanced. The experiment also showed that the controlled every-day life traffic normally used in the VTI driving simulator makes subjects drive faster than in autonomous traffic.

  • 38.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Häll, Carl-Henrik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Smith, Göran
    Viktoria Swedish ICT, Gothenburg, Sweden.
    Habibovic, Azra
    Viktoria Swedish ICT, Gothenburg, Sweden.
    Anund, Anna
    Swedish National Road and Transport Research Institute, VTI.
    Dynamic bus lanes in Sweden – a pre-study: PROVDYK – Final report2015Report (Other academic)
    Abstract [en]

    Dedicated bus lanes and bus streets have, in recent years, become common measures for prioritisation of public transport. By ensuring free path along routes, they increase average speed and travel time reliability of buses. However, a major drawback is that the total traffic capacities of the roads decrease. Hence, these measures are only suitable when the total traffic flow is low enough to allow for a reduction of lanes; if it is possible to reroute adjacent traffic; or if it is possible to extend the road with additional lanes. A supplementary priority measure could be to utilize dynamic bus lanes (also called intermittent bus lanes and bus lanes with intermittent priority). Dynamic bus lanes are only dedicated for buses when and where the buses need them, and otherwise open for all vehicles to use. At any given point, adjacent traffic is only permitted from using the dynamic bus lanes at the stretches where buses are in the vicinity. This report presents the results from a pre-study, investigating the potential that dynamic bus lanes could have as a priority measure for public transport in a Swedish context.

    Knowledge of situations in which dynamic bus lanes have the highest potential, and their implementation requirements is scarce. It is moreover uncertain how they would affect traffic safety, level of service and user experience. Two real world field tests have been conducted; one in Lisbon and one in Melbourne. The installation in Melbourne is now permanently applied for trams on one street. The field test in Lisbon was on the contrary not made permanent, although the results showed large benefits for buses and limited adverse effects on other vehicles. Dynamic bus lanes have also been investigated by means of traffic analysis and traffic simulation experiments. In general, these studies show that the effects on travel time for buses are in general positive and delays for other vehicles are limited. Results from example calculations in this pre-study show that this also could be true for a Swedish context. It has also been identified that the effects on travel times are highly dependent on factors such as: the total traffic flow; the bus flow, the capacity of roads and junctions; the distance between junctions and bus stops; the type of bus stops and the yielding rules at bus stops. The effects on travel time variations are unclear and need to be further investigated.

    Few rigorous research studies have in general been undertaken to measure the user experiences or road safety implications of bus priority schemes, and evidence from those that do exist are mixed. Anyhow, the experiences from Lisbon and Melbourne suggest that drivers in adjacent lanes in general understand and accept that they are deprived of the right to use the lane when the buses need it, and that they will behave appropriately. Neither of the field tests has observed any negative impact on road safety. A workshop was conducted within this pre-study in order to further investigate plausible user experiences. The results indicate that bus drivers’ stress levels could be reduced; the relative attractiveness of travelling by bus might rise; and that motorists probably would experience the introduction of dynamic bus lanes as neither good nor bad, as long as the system is fairly intuitive.

    Technical solutions for implementing dynamic bus lanes exist. A dynamic bus lane system would require development of a system control unit and integration with bus sensors, sensors for traffic flow measurement, variable message signs (to inform road users of the current status of the dynamic bus lane) and traffic signals. It is moreover, in Sweden, possible to develop a local traffic rule that regulates dynamic bus lanes. However, the rule needs to be properly specified, designed, communicated, signed and marked on the road.

    The overall conclusion form the pre-study is that dynamic bus lanes could be a useful complementary priority measure for public transport vehicles in Sweden, especially when dedicated bus lanes are not feasible or desirable. However, a real world installation in Sweden, including pre implementation traffic analysis, is needed, in order to further investigate the potential and consequences. Thus, the next step is to plan for an implementation on a specific road stretch. That would include both estimation of costs, and generate input to further studies of effect on level of service and user experience. Driving simulators and traffic simulation experiments are applicable methods for investigating these issues.

  • 39.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Lundgren, Jan
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Adlers, Mikael
    Swedish National Road and Transport Research Institute (VTI), VTI, SE-581 95 Linköping, Sweden.
    Matstoms, Pontus
    Swedish National Road and Transport Research Institute (VTI), VTI, SE-581 95 Linköping, Sweden.
    A Framework for Simulation of Surrounding Vehicles in Driving Simulators2008In: ACM Transactions on Modeling and Computer Simulation, ISSN 1049-3301, E-ISSN 1558-1195, Vol. 18, no 3Article in journal (Refereed)
    Abstract [en]

    This article describes a framework for generation and simulation of surrounding vehicles in a driving simulator. The proposed framework generates a traffic stream, corresponding to a given target flow and simulates realistic interactions between vehicles. The framework is based on an approach in which only a limited area around the driving simulator vehicle is simulated. This closest neighborhood is divided into one inner area and two outer areas. Vehicles in the inner area are simulated according to a microscopic simulation model including advanced submodels for driving behavior while vehicles in the outer areas are updated according to a less time-consuming mesoscopic simulation model. The presented work includes a new framework for generating and simulating vehicles within a moving area. It also includes the development of an enhanced model for overtakings and a simple mesoscopic traffic model. The framework has been validated on the number of vehicles that catch up with the driving simulator vehicle and vice versa. The agreement is good for active and passive catch-ups on rural roads and for passive catch-ups on freeways, but less good for active catch-ups on freeways. The reason for this seems to be deficiencies in the utilized lane-changing model. It has been verified that the framework is able to achieve the target flow and that there is a gain in computational time of using the outer areas. The framework has also been tested within the VTI Driving simulator III.

  • 40.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Matstoms, Pontus
    VTI .
    Nya V/D-funktioner på väg. Preliminära funktioner för tätortsmiljöer baserade på ny metod2006Report (Other academic)
  • 41.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Matstoms, Pontus
    VTI .
    TU06 - Nya V/D-funktioner för tätort2007In: Transportforum,2007, Linköping: VTI , 2007Conference paper (Other academic)
    Abstract [sv]

        

  • 42.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Matstoms, Pontus
    VTI .
    TU06 - Nya V/D-funktioner för tätort - revidering av TU71-funktionerna2006Report (Other academic)
  • 43.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Rydergren, Clas
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Matstoms, Pontus
    Swedish National Road and Transport Research Institute VTI.
    Estimation of Volume Delay Functions for Urban Environments Based on an Analytical Intersection Model2008In: Transportation Research Board 87th Annual Meeting,2008, Washington: Transportation Research Board , 2008Conference paper (Refereed)
    Abstract [en]

    This paper describes a method for estimating parameters in volume delay functions. The volume delay function is a central part of static traffic assignment models and describes how the travel time on road link changes with traffic demand. The proposed estimation method is based on that the volume delay function is divided into two parts, one part describing the link travel time and delay and one part describing the intersection delay. The parameters for the link and intersection parts are estimated separately. Collecting data for the link part is seldom a problem. However, earlier experiences have shown that it is both difficult and expensive to collect data on intersection delay. We have used an approach in which the intersection delay data is taken from a model for calculating intersection delay, in this case the analytical intersection model CAPCAL. The developed estimation method has been exemplified on one road type and road environment. A sensitivity analysis has been conducted in order to investigate how large influence that the different assumptions on the road factors have on the volume delay function. The conclusions are that the flow levels on the cross road, the intersection density, the share of straight forward traffic, and the share of different intersection types has the largest influence, and thus should be prioritized when collecting road type data. 

  • 44.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Simonsson, Jenny
    VTI .
    Simulerad trafik till VTI: s körsimulator - en förstudie2003Report (Other academic)
    Abstract [sv]

      

  • 45.
    Olstam, Johan
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Tapani, Andreas
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    A review of guidelines for applying traffic simulation to level-of-service analysis2011In: / [ed] Haris N. Koutsopoulos och Karl L. Bang, Elsevier, 2011, p. 771-780Conference paper (Refereed)
    Abstract [en]

    Microscopic traffic simulation is often used as an alternative or complementary tool to analytical methods and procedures for level-of-service analyses of road traffic facilities. The increased usage of traffic simulation for level-of-service analysis has raised a need for guidelines on how to apply and use traffic simulation models. Many countries have developed or are currently developing traffic simulation guidelines. This is also the case in Sweden, were the new Swedish highway capacity manual will include a chapter on traffic simulation. This paper presents a survey of the current traffic simulation guidelines in USA, Germany, UK, Denmark and Sweden. The guidelines have been analysed with respect to the aspects covered: when to apply simulation; the workflow of a simulation study; data collection needs; calibration and validation; experimental design; statistical analysis; and calculation of level-of-service measures. The guidelines analysed are focused on different aspects and none of them covers all of the topics listed above. Some of the guidelines are connected to specific simulation software packages and some are written in a more general manner. Most of the aspects covered are general and applicable in any country. The main reason for developing country specific guidelines is often a need for guidelines in the local language. Experimental design and statistical analysis are not treated extensively in the guidelines; neither do the guidelines discuss how to deal with calibration based on limited real world measurements. Calculation of level-of-service measures are quite extensively treated in some of the guidelines and to a little extent in others. All of the guidelines contain important contributions for the simulation chapter of the new Swedish highway capacity manual

  • 46.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Tapani, Andreas
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    comparison of car-following models2004In: Transportforum,2004, Linköping: VTI , 2004Conference paper (Other academic)
  • 47.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Tapani, Andreas
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology.
    Comparison of car-following models2004Report (Other academic)
  • 48.
    Olstam, Johan
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Tapani, Andreas
    Linköping University, The Institute of Technology. Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Enhancements to the Intelligent Driver Model2010In: TRB 89th annual meeting Compendium of Papers DVD, Washington D.C.: Transportation Research Board , 2010Conference paper (Other academic)
    Abstract [en]

    This paper presents a modified version of the Intelligent Driver Model (IDM) [M. Treiber, A. Hennecke, and D. Helbing, Phys. Rev. E. 62, 2 (2000)]. The IDM is a car-following model. A car-following model controls the accelerations of individual vehicles in a microscopic traffic simulation model. The original IDM has been observed to result in negative vehicle accelerations in situations where the distance to the preceding vehicle is much larger than the estimated desired safety distance. In this paper, we propose a modified function for the interaction with preceding vehicles which do not include this model property. A comparison of the results of simulations with the original and the modified IDM shows that the modified IDM results in higher average speed for a specific flow, a less steep speed-flow relationship and higher capacity. The speed-flow relationships of simulations with the modified IDM are also shown to better match the speed-flow relationships in real traffic on Swedish freeways. The differences between the results for the original and the modified IDM increase if the models are extended to include drivers' anticipation of the downstream traffic condition.

  • 49.
    Pyddoke, Roger
    et al.
    Statens väg- och transportforskningsinstitut, Transportekonomi, VTI.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Yahya, Mohammad-Reza
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Karlsson, Rune
    Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Trängsel och knapphet på väg, järnväg och i kollektivtrafik: delstudie inom SAMKOST2014Report (Other academic)
    Abstract [en]

    The purpose of this study is to take stock of Swedish data and studies that could form the basis of the estimation of marginal costs for congestion on roads and scarcity of railway capacity. Furthermore, the development of methods to estimate and evaluate the congestion in public transport is discussed. The Transport Administration’s investigation from 2013 indicates that there are persistent congestion problems in Stockholm that would be affected by adjustments to the toll cordon, congestion tax levels and differentiation with respect to time and place. A second part quantifies congestion in the road network outside urban areas by the use of extensive flow and velocity measurements from the E4 south of Stockholm as an example. This choice is justified as an example of a highly trafficked road link where the speed reductions occur regularly. The results show that the flows during May to December 2013 regularly were so high that speed dropped below 60 kilometer per hour for long periods. The marginal cost of congestion can be expressed as the change in the cost of a change in density and is highest at densities close to the road’s capacity. When the density is greatest, the marginal cost of one further car is about 10 SEK per kilometer. Compared to the taxes on petrol which is about 0,34 SEK per kilometer, which is considered to cover the marginal costs of all other externalities including carbon emissions. Thus, congestion costs may therefore be considered significant. For train slots, this study has used the Transport Administration’s electronic record of the operators’ requests for train slots from the National train plan for 2013 and the corresponding documentation of the determined slots. We find that the total of allocated slots for the largest operator of passenger trains in Sweden, SJ, received 99 percent of the slots it had applied for and Green Cargo 97 percent. This is not a strong indication of scarcity. For crowding in public transport there are a number of British studies of the valuation of travel in crowded conditions in passenger trains. These valuations have mostly been calculated as a multiplicative factor on time values when the passengers travel without crowding. The report presents studies that show that the willingness to pay may be substantially higher for a shorter travel time if the trip takes place in crowded conditions.

  • 50.
    Strömgren, Per
    et al.
    Division of Transport planning, Economics and Engineering, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Olstam, Johan
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering. Swedish National Road and Transport Research Institute (VTI), Linköping, Sweden.
    A Model for Capacity Reduction at Roadwork Zone2016In: International Symposium on Enhancing Highway Performance (ISEHP), (7th International Symposium on Highway Capacity and Quality of Service, 3rd International Symposium on Freeway and Tollway Operations), Elsevier, 2016, Vol. 15, p. 245-256Conference paper (Refereed)
    Abstract [en]

    This paper presents an investigation of capacity reduction in connection with roadwork zones. The paper presents a state-of-the-art description on roadwork effects on capacity. Based on the literature on this topic the most important parameters that should be incorporated in a Swedish capacity manual for the operation and maintenance roadwork are: the proportion of heavy traffic; lane width; number of closed lanes; closed road shoulder; proportion of commuter traffic; and length of roadwork zone. The paper presents a comparison of a composite model of correction factors from Germany, USA and Denmark and the Dutch model for computation of capacity reduction. The comparison show that the two models essentially gives the same results. Based on these results a model was developed. The model developed was validated using empirical data from a full scale test at the motorway network in Gothenburg. The throughput was measured in two cases during the morning and afternoon peak hour. The capacity for the normal site conditions was estimated based on traffic flow and speed data from the same site. The result shows that the empirically estimated capacity reduction is consistent with the reduction calculated with the new model for the different road work designs evaluated. The conclusion is that the model developed seems to be valid for capacity reduction estimations of roadworks on Swedish motorways but that more empirics are needed to ensure general validity.

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