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Grumert, E. & Tapani, A. (2020). Bottleneck mitigation through a variable speedlimit system using connected vehicles. Paper presented at 20th EURO-Working-Group-on-Transportation Meeting (EWGT), Budapest Univ Technol & Econ, Fac Transportat Engn & Vehicle Engn, Budapest, Hungary, Sep 04-06, 2017.. Transportmetrica A: Transport Science, 16(2), 213-233
Open this publication in new window or tab >>Bottleneck mitigation through a variable speedlimit system using connected vehicles
2020 (English)In: Transportmetrica A: Transport Science, ISSN 2324-9935, E-ISSN 2324-9943, Vol. 16, no 2, p. 213-233Article in journal (Refereed) Published
Abstract [en]

Variable speed limit (VSL) systems are used to improve the traffic conditions by adjusting the speed limits based on the current traffic situation. Advances in vehicle technology have made it possible to use connected vehicles in VSL systems. Connected vehicles can continuously transmit information about their speed and location, which can be used to estimate the current traffic conditions at arbitrary locations. In this study, we propose a VSL system based on connected vehicles. The aim is to also allow application of VSLs for non-recurrent bottleneck mitigation at arbitrary locations, unlike today's systems which require densely placed detectors or are limited to beforehand known bottleneck locations. The proposed system is evaluated by microscopic traffic simulation. The results indicate that the VSL system manage to improve traffic efficiency in a simulated incident scenario.

Place, publisher, year, edition, pages
Taylor & Francis, 2020
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-161095 (URN)10.1080/23249935.2018.1547332 (DOI)000508971600004 ()2-s2.0-85057525365 (Scopus ID)
Conference
20th EURO-Working-Group-on-Transportation Meeting (EWGT), Budapest Univ Technol & Econ, Fac Transportat Engn & Vehicle Engn, Budapest, Hungary, Sep 04-06, 2017.
Funder
Swedish Transport Administration
Available from: 2019-10-22 Created: 2019-10-22 Last updated: 2022-06-16Bibliographically approved
Grumert, E., Bernhardsson, V., Ekström, J., Gundlegård, D., Ringdahl, R. & Tapani, A. (2019). Variabla hastighetsgränser för Stockholms motorvägsnät: Effekter av alternativa algoritmer och möjligheter till styrning genom skattade trafiktillstånd. Linköping: Swedish National Road and Transport Research Institute (VTI)
Open this publication in new window or tab >>Variabla hastighetsgränser för Stockholms motorvägsnät: Effekter av alternativa algoritmer och möjligheter till styrning genom skattade trafiktillstånd
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2019 (Swedish)Report (Other academic)
Alternative title[en]
Variable speed limits for Stockholm’s urban motorways : Effects of differentalgorithms and the possibility to control by the use of estimated traffic states
Abstract [sv]

Variabla hastighetsgränser är väl utbrett på Stockholms stadsnära motorvägar och en del av Stockholms Motorway Control System (MCS). Målet med dagens system är att minska risken för olyckor och följdolyckor vid låga hastigheter, trafikstockningar m.m. Detta görs genom att mäta medelhastigheten med hjälp av fasta detektorer och uppdatera hastigheten som visas på variabla meddelandeskyltar utifrån rådande trafiktillstånd. I och med att efterfrågan på resor i Stockholm under rusningstid överstiger den tillgängliga kapaciteten i vägnätet är behovet av ett effektivt trafiksystem stort. Variabla hastighetsgränser kan bidra till ökad framkomlighet, men då dagens system har som målsättning att öka säkerheten är effekter som leder till ökad framkomlighet begränsade. Dessutom finns det i dagens system ett stort beroende av fungerande detektorer som mäter trafiktillståndet så korrekt som möjligt för att valet av hastighet ska kunna bestämmas på ett effektivt sätt.

Syftet med den här rapporten är att undersöka alternativa styralgoritmer för att bestämma variabla hastighetsgränser på Stockholms motorvägsnät. Målet är att öka framkomligheten jämfört med dagens system. Två olika sträckor med olika komplexitet, trafiksituation och problematik studeras. Valet av studerade styralgoritmer för de olika sträckorna väljs för att på bästa sätt motverka den problematiken som uppstår på de specifika sträckorna. Därmed kan val av algoritmer komma att skilja sig åt beroende på sträcka. I projektet utvärderas också om estimering av trafiktillståndet kan användas för att förbättra informationsflödet till algoritmerna då detektorer inte fungerar som de ska eller helt saknas, vilket i sin tur kan leda till förbättrad anpassning av de variabla hastighetsgränserna. Detta görs av för en av de studerade sträckorna. Styralgoritmerna utvärderas med mikroskopisk trafiksimulering och metoden utvecklad i projektet Mobile Millenium Stockholm (MMS), som bygger på en makroskopisk trafikflödesmodell och Kalman filtrering, används för estimering av trafiktillståndet.

Resultatet visar att det finns styralgoritmer med potential att öka framkomligheten. Valet av styralgoritm är dock beroende av typ av trafiksituation, vägdesignens komplexitet och trafikförhållanden på vägen. Det betyder att olika styralgoritmer kan prestera olika bra beroende på vilken vägsträcka man studerar. Vidare är estimering av trafiktillståndet användbart vid förlorad information på grund av icke-fungerande detektorer eller som komplement till detektorer för att minska mängden stationär utrustning.

Abstract [en]

Variable speed limits are commonly used on Stockholm’s urban motorways, and it is part of the Stockholm Motorway Control System (MCS). The goal of today’s system is to reduce the risk of accidents during congested conditions, traffic jams etc. This is done by updating the speed limits shown on variable message signs based on a measured average speed at fixed detectors. As the demand for travel in Stockholm during peak-hours exceeds the available capacity in the road network, the need for an efficient traffic system is high. Variable speed limit systems have the possibility to contribute to increased efficiency, but since today’s system aims to increase safety, effects that lead to increased efficiency are limited. Further, in todays’ variable speed limit systems there are a large dependency of precise and available measurements from stationary detectors to be able to display speed limits that reflects the current traffic conditions. The purpose of this report is to investigate alternative control algorithms to decide on the variable speed limits to be displayed at variable message signs on the urban motorway of Stockholm.

The goal is to increase efficiency compared to today's system. Two different road stretches with different complexity and different traffic conditions, resulting in two different types of congestion, are studied. Thereby, the studied control algorithms on the two road stretches are chosen based on the possibility of solving a specific problematic traffic situation in the best way. Hence, the studied control algorithms might differ for the two road stretches. Furthermore, for one of the roads stretches it is investigated if estimation of the traffic state can be used as input to the control algorithm as a complement to missing and erogenous measurements from stationary detectors in order to improve the calculations of the variable speed limits. The control algorithms are evaluated with microscopic traffic simulation and the method developed in the project Mobile Millenium Stockholm (MMS), using a macroscopic traffic flow model together with a Kalman filter, is used for estimation of the traffic state.

The result shows that there are control algorithms with the potential to increase efficiency. However, the choice of suitable control algorithm for improving traffic efficiency is dependent on the traffic situation, the complexity of the road design and the traffic conditions. Furthermore, estimation of the traffic state is useful when information is lost due to malfunctioning detectors or as a complement to reduce the amount of stationary detectors.

Place, publisher, year, edition, pages
Linköping: Swedish National Road and Transport Research Institute (VTI), 2019. p. 52
Series
VTI Rapport, ISSN 0347-6030, E-ISSN 0347-6030 ; 1006
Keywords
Traffic control, variable speed limits, predictive control, microscopic traffic simulation, macroscopic traffic simulation, Trafikstyrning, variabla hastighetsgränser, prediktiv styrning, mikroskopisk trafiksimulering, makroskopisk trafiksimulering
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-158028 (URN)
Available from: 2019-06-24 Created: 2019-06-24 Last updated: 2019-06-24Bibliographically approved
Grumert, E. F. (2018). Using Connected Vehicles in Variable Speed Limit Systems:: System Design and Effects. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Using Connected Vehicles in Variable Speed Limit Systems:: System Design and Effects
2018 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Motorway traffic management systems are useful for improving the traffic conditions on urban motorways. One of the most common motorway traffic management systems are variable speed limit systems. These systems adapt the speed limits based on the prevailing traffic conditions measured by roadside detectors and recommended or compulsory speed limits are shown on variable message signs installed on gantries over the road.Thesystems consist of three parts; the control algorithm used to determine which speed limit to be displayed, a method for estimating the traffic conditions to be used as input for the control algorithm and the infrastructure for application of the variable speed limits. The goal of the systems is often to increase safety or efficiency.

Recent development in the field of connected vehicles have opened up for a new type of data source, as the status of a connected vehicle and its surroundings can be communicated at arbitrary locations. Hence, by the use of connected vehicles in variable speed limit systems there is a potential of reducing the amount of roadside equipment. It is even possible to control the connected vehicles towards the current speed limit without the use of variable message signs. This allows for the application of variable speed limits at arbitrary locations.

The aim of this thesis is to examine how connected vehicles can be used to improve the efficiency of variable speed limit systems. The thesis contribute with new and improved methods using connected vehicles in all three parts of a variable speed limit system. The suggested methods are evaluated by microscopic traffic simulation. The overall conclusion is that the use of connected vehicles in variable speed limit systems can contribute to improvements in traffic efficiency compared to existing systems.

The six papers included in the thesis can be summarized as follows. First, it is shown that traditional variable speed limit systems can be effective for improving the traffic conditions on the motorway and the results can be comparable to more costly alterations by reconstruction of the infrastructure to increase the capacity. Next, the usefulness of connected vehicles for application and control of the speed limits in an existing variable speed limit system is investigated. It is concluded that the design of the control algorithm and the accuracy of the estimated traffic conditions have a great effect on the final outcome of the system. The design of the control algorithm is then examined by evaluation of a number of control algorithms with respect to safety, efficiency and environmental impacts. The main benefits and drawbacks of the algorithms are highlighted and desirable characteristics to include when designing a control algorithm are identified. In two studies, methods making use of connected vehicles for estimating the traffic conditions are proposed. The results show that connected vehicles are useful for improving the accuracy of the estimated traffic conditions through the inclusion of more detailed information and information at locations where detector measurements are not available. Finally, a variable speed limit system is proposed in which connected vehicles play a central role in the estimation of the traffic conditions, as well as in the control algorithm and for application of the speed limit. The system is shown to be useful for improving traffic efficiency during an incident at an arbitrary location along the controlled road.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2018. p. 80
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1919
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-147049 (URN)10.3384/diss.diva-147049 (DOI)9789176853412 (ISBN)
Public defence
2018-04-20, K3, Campus Norrköping, Norrköping, 13:15 (English)
Opponent
Supervisors
Available from: 2018-04-10 Created: 2018-04-10 Last updated: 2019-09-30Bibliographically approved
Grumert, E. & Tapani, A. (2017). Using connected vehicles in a variable speed limit system. In: : . Paper presented at 20th EURO Working Group on Transportation Meeting, EWGT, Budapest, Hungary - 4-6 September, 2017 (pp. 85-92). Elsevier, 27
Open this publication in new window or tab >>Using connected vehicles in a variable speed limit system
2017 (English)Conference paper, Published paper (Refereed)
Abstract [en]

Variable speed limit systems are used to improve the traffic conditions on specific road stretches. This is done by adjusting the speed limits according to current traffic situations. A variable speed limit system usually consist of stationary detectors to estimate the traffic state and variable message signs at predefined locations for the application of new speed limits. Advances in vehicle technology have made it possible to use connected vehicles to improve existing variable speed limit systems. Connected vehicles can continuously transmit information about speed and location. This can be used to get more detailed information about the traffic state. By including information from connected vehicles in a variable speed limit system there is a potential to identify bottlenecks also in between stationary detectors. Further, it is possible to use direct control of the connected vehicles to adjust vehicle speeds towards the new traffic situation. In this study, we propose such a variable speed limit system based on connected vehicles. The aim is to allow for application of variable speed limits in connection with non-recurrent bottlenecks. The proposed system is evaluated with respect to traffic efficiency using microscopic traffic simulation. An incident is simulated as an example of a non-recurrent bottleneck. The traffic performance when the proposed VSL system is applied is compared to the performance without the system. The results indicate that the VSL system manage to improve traffic efficiency in a majority of the simulated cases.

Place, publisher, year, edition, pages
Elsevier, 2017. p. 7
Series
Transportation Research Procedia, ISSN 2352-1465 ; 27
Keywords
connected vehicles; variable speed limit; traffic management; microscopic traffic simulation; traffic efficiency
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-178606 (URN)10.1016/j.trpro.2017.12.050 (DOI)000483931700001 ()2-s2.0-85039968875 (Scopus ID)
Conference
20th EURO Working Group on Transportation Meeting, EWGT, Budapest, Hungary - 4-6 September, 2017
Funder
Swedish Transport Administration
Available from: 2021-08-24 Created: 2021-08-24 Last updated: 2021-09-03Bibliographically approved
Grumert, E., Tapani, A. & Ma, X. (2016). Evaluation of Four Control Algorithms Used in Variable Speed Limit Systems. In: TRB 95th Annual Meeting Compendium of Papers: . Paper presented at Transportation Research Board 95th Annual Meeting, Washington D.C., USA, January 10-14, 2016. Washington: Transportation Research Board, Article ID 16-2880.
Open this publication in new window or tab >>Evaluation of Four Control Algorithms Used in Variable Speed Limit Systems
2016 (English)In: TRB 95th Annual Meeting Compendium of Papers, Washington: Transportation Research Board , 2016, article id 16-2880Conference paper, Published paper (Refereed)
Abstract [en]

Control algorithms used for deciding on the speed limits in variable speed limit systems are crucial for the performance of the system. Today, many of the control algorithms used are based on fixed thresholds in speed and/or flow for lowering and increasing the speed limit. The algorithms are not necessarily reflecting the conditions on the road, which might lead to low traffic efficiency. Our hypothesis is that by use of a simple and efficient control algorithm that is better in reflecting the conditions on the road, both traffic efficiency and traffic safety could be increased. In this study, four control algorithms used in variable speed limit systems, and fulfilling the above criteria, are evealuted through microscopic traffic simulation. Performance indicators related to traffic safety, traffic efficiency and environmental impacts are presented. The results show that the design of, and the objective with, the control algorithm have a great impact on the performance. Moreover, the time needed for incident detection, the duration of and the size of the speed limit reduction and the location of the congestion are of importance for the performance of the control algorithms. These results will be of importance for design and implementation of future efficient variable speed limit systems.

Place, publisher, year, edition, pages
Washington: Transportation Research Board, 2016
Keywords
variable speed limit systems, control algorithms, microscopic traffic simulation
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-129518 (URN)
Conference
Transportation Research Board 95th Annual Meeting, Washington D.C., USA, January 10-14, 2016
Available from: 2016-06-20 Created: 2016-06-20 Last updated: 2016-06-29Bibliographically approved
Grumert, E., Ma, X. & Tapani, A. (2015). Analysis of a cooperative variable speed limitsystem using microscopic traffic simulation. Transportation Research Part C: Emerging Technologies, 52, 173-186
Open this publication in new window or tab >>Analysis of a cooperative variable speed limitsystem using microscopic traffic simulation
2015 (English)In: Transportation Research Part C: Emerging Technologies, ISSN 0968-090X, E-ISSN 1879-2359, Vol. 52, p. 173-186Article in journal (Refereed) Published
Abstract [en]

Variable speed limit systems where variable message signs are used to show speed limits adjusted to the prevailing road or traffic conditions are installed on motorways in many countries. The objectives of variable speed limit system installations are often to decrease the number of accidents and to increase traffic efficiency. Currently, there is an interest in exploring the potential of cooperative intelligent transport systems including communication between vehicles and/or vehicles and the infrastructure. In this paper, we study the potential benefits of introducing infrastructure to vehicle communication, autonomous vehicle control and individualized speed limits in variable speed limit systems. We do this by proposing a cooperative variable speed limit system as an extension of an existing variable speed limit system. In the proposed system, communication between the infrastructure and the vehicles is used to transmit variable speed limits to upstream vehicles before the variable message signs become visible to the drivers. The system is evaluated by the means of microscopic traffic simulation. Traffic efficiency and environmental effects are considered in the analysis. The results of the study show benefits of the infrastructure to vehicle communication, autonomous vehicle control and individualized speed limits for variable speed limit systems in the form of lower acceleration rates and thereby harmonized traffic flow and reduced exhaust emissions.

Place, publisher, year, edition, pages
Elsevier, 2015
Keywords
Cooperative systems;Intelligent transport systems;Infrastructure to vehicle communication;Variable speed limit;Microscopic traffic simulation; Emission model
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-115013 (URN)10.1016/j.trc.2014.11.004 (DOI)000352252400012 ()
Available from: 2015-03-06 Created: 2015-03-06 Last updated: 2018-04-10
Grumert, E. (2014). Cooperative Variable Speed Limit Systems: Modeling and Evaluation using Microscopic Traffic Simulation. (Licentiate dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Cooperative Variable Speed Limit Systems: Modeling and Evaluation using Microscopic Traffic Simulation
2014 (English)Licentiate thesis, monograph (Other academic)
Abstract [en]

During the last decades the road traffic has increased tremendously leading to congestion, safety issues and increased environmental impacts. As a result, many countries are continuously trying to find improvements and new solutions to solve these issues. One way of improving the traffic conditions is by the use of so called intelligent transport systems, where information and communication technologies are being used for traffic management and control. One such system commonly used for traffic management purposes are variable speed limit systems. These systems are making use of signs to show speed limits adjusted to the prevailing road or traffic conditions. The rapid development in telecommunication technologies has enabled communication between vehicles, and between vehicles and the infrastructure, so called cooperative systems. This opens up for  the possibility to further improve the performance of a standard variable speed limit system by adding cooperative system features.

The overall aim of this thesis is to investigate the potential benefits of incorporating infrastructure to vehicle communication and autonomous control to an existing variable speed limit system. We show how such a cooperative variable speed limit system can be modeled and evaluated by the use of microscopic traffic simulation. Results from the evaluation indicate increased flow harmonization in terms of narrowing of the acceleration rate distribution and reduced exhaust emissions.

Further, we compare four control algorithms for deciding on speed limits in variable speed limit systems. Differences in the resulting traffic performance between the control algorithms are quantified by the use of microscopic traffic simulation. It is concluded that the dened objective for the algorithms have a decisive influence on the effects of the variable speed limit system.

The results from this thesis are useful for further development of variable speed limit systems, both with respect to incorporating cooperative features and by improving the speed setting control algorithms.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2014. p. 144
Series
Linköping Studies in Science and Technology. Thesis, ISSN 0280-7971 ; 1670
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-106926 (URN)978-91-7519-292-5 (ISBN)
Presentation
2014-06-11, K3, Kåkenhus, Campus Norrköping, Linköpings universitet, Norrköping, 13:15 (Swedish)
Opponent
Supervisors
Available from: 2014-05-27 Created: 2014-05-27 Last updated: 2015-03-06Bibliographically approved
Grumert, E., Tapani, A. & Ma, X. (2013). Effects of a Cooperative Variable Speed Limit System on Traffic Performance and Exhaust Emissions. In: TRB 92nd Annual Meeting Compendium of Papers: . Paper presented at Transport Research Board 92nd Annual Meeting, 13-17 January 2013, Washington DC, USA.
Open this publication in new window or tab >>Effects of a Cooperative Variable Speed Limit System on Traffic Performance and Exhaust Emissions
2013 (English)In: TRB 92nd Annual Meeting Compendium of Papers, 2013Conference paper, Published paper (Refereed)
Abstract [en]

Variable Speed Limit Systems (VSLS) where variable message signs show speed limits based on traffic or road conditions exist on motorways in many countries. The purpose of the VSLS is to decrease the number of accidents while increasing efficiency of traffic system. Cooperative systems are a type of intelligent transport system that has received increasing interest lately. The central part of a cooperative system is communication between vehicles and/or vehicles and the infrastructure. In this paper, a cooperative systems extension of a VSLS is proposed and evaluated by means of microscopic traffic simulation. In the proposed cooperative VSLS, communication between the vehicles and the infrastructure is made available via a roadside unit communicating the speed limits to vehicles upstream on the road. Both aggregate and micro-scale emission models are used to estimate emission from vehicle states in traffic flow. The results of the study show that the cooperative VSLS has a potential to contribute to flow harmonization and to reduce environmental impacts. The emission estimates in the study are dependent on the emission models being applied.

Series
Transport Research Board 92nd Annual Meeting
Keywords
Exhaust gases; Intelligent transportation systems; Traffic flow; Traffic simulation; Variable speed limits; Vehicle to roadside communications; Vehicle to vehicle communications; Cooperative systems
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-92746 (URN)
Conference
Transport Research Board 92nd Annual Meeting, 13-17 January 2013, Washington DC, USA
Available from: 2013-05-20 Created: 2013-05-20 Last updated: 2015-03-06
Grumert, E. & Tapani, A. (2013). Microscopic traffic simulation for evaluation of a cooperative variable speed limit system. In: 1st SUMO User Conference 2013. Proceedings, Berichte aus dem DLR-Institut für Verkehrssystemtechnik, Band 21: . Paper presented at 1st SUMO user conference 2013, May 15-17, Berlin-Adlershof, Germany (pp. 147-164). Berlin: Deutsches Zentrum für Luft- und Raumfahrt e.V. Institut für Verkehrssystemtechnik, Berlin-Adlershof
Open this publication in new window or tab >>Microscopic traffic simulation for evaluation of a cooperative variable speed limit system
2013 (English)In: 1st SUMO User Conference 2013. Proceedings, Berichte aus dem DLR-Institut für Verkehrssystemtechnik, Band 21, Berlin: Deutsches Zentrum für Luft- und Raumfahrt e.V. Institut für Verkehrssystemtechnik, Berlin-Adlershof , 2013, p. 147-164Conference paper, Published paper (Refereed)
Abstract [en]

Variable Speed Limit Systems (VSLS) where gantries are showing speed limits based on, for example, traffic volume or other road or traffic conditions exists on motorways in many countries. The aim of the VSLS is usually to improve traffic efficiency. Lately, cooperative intelligent transport systems allowing for communication between vehicles and/or vehicles and the infrastructure has received increasing interest. A cooperative VSLS, utilizing communication between vehicles and the infrastructure, could possibly result in further improved traffic efficiency and decreased exhaust emissions and fuel consumption. In this paper, a cooperative VSLS is evaluated by the use of a microscopic traffic simulator. The cooperative VSLS is described together with a discussion on how the modeling of the cooperative VSLS and the assumptions made regarding vehicles behavior will impact the final results of the evaluation. Results from the simulations are presented with in terms of traffic efficiency and exhaust emissions.

Place, publisher, year, edition, pages
Berlin: Deutsches Zentrum für Luft- und Raumfahrt e.V. Institut für Verkehrssystemtechnik, Berlin-Adlershof, 2013
Series
Reports of the DLR-Institute of Transportation Systems, ISSN 1866-721X ; 21
Keywords
microscopic traffic simulation, SUMO, Variable Speed Limit Systems (VSLS), cooperative systems, environmental impacts, traffic efficiency
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-102882 (URN)
Conference
1st SUMO user conference 2013, May 15-17, Berlin-Adlershof, Germany
Available from: 2014-01-07 Created: 2014-01-07 Last updated: 2015-03-06Bibliographically approved
Grumert, E. & Tapani, A. (2012). Impacts of a Cooperative Variable Speed Limit System. Paper presented at 8th International Conference on Traffic and Transportation Studies (ICTTS 2012). Procedia - Social and Behavioral Sciences, 43, 595-606
Open this publication in new window or tab >>Impacts of a Cooperative Variable Speed Limit System
2012 (English)In: Procedia - Social and Behavioral Sciences, ISSN 1877-0428, Vol. 43, p. 595-606Article in journal (Refereed) Published
Abstract [en]

Variable Speed Limit Systems (VSLS) where variable message signs show speed limits based on, for example,traffic volume or road conditions exists on motorwaysin many countries. The purpose of the VSLS is to decrease the number of accidents and to increase traffic efficiency. Cooperative systems are a type of intelligent transport system that has received increasing interest lately. The central part of a cooperative system is communication between vehicles and/or vehicles and the infrastructure. In this paper, a cooperative systems extension of a VSLS is proposed and evaluated by means of traffic simulation. By adding cooperative systems functionality to an existing VSLS there is a potential for further increase in traffic efficiency and also to reduce the environmental impacts of the traffic on the road. In the proposed cooperative VSLS, communication between the vehicles and the infrastructure is made available via a roadside unit communicating the speed limits to vehicles upstream on the road. The results of the study show that the cooperative VSLS has a potential to contribute to flow harmonization and to reduce environmental impacts.

Place, publisher, year, edition, pages
Elsevier, 2012
Keywords
cooperative systems, intelligent transport systems (ITS), variable speed limit systems (VSLS), traffic simulation, environmental impacts, traffic efficiency
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-91522 (URN)10.1016/j.sbspro.2012.04.133 (DOI)000305965600063 ()
Conference
8th International Conference on Traffic and Transportation Studies (ICTTS 2012)
Projects
Cooperative systems for increased energy efficiency and reduced environmental impact
Available from: 2013-04-26 Created: 2013-04-26 Last updated: 2018-03-09
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-5531-0274

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