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Breyer, N., Rydergren, C. & Gundlegård, D. (2018). Cellpath Routing and Route Traffic Flow Estimation Based on Cellular Network Data. The Journal of urban technology (2), 85-104
Open this publication in new window or tab >>Cellpath Routing and Route Traffic Flow Estimation Based on Cellular Network Data
2018 (English)In: The Journal of urban technology, ISSN 1063-0732, E-ISSN 1466-1853, no 2, p. 85-104Article in journal (Refereed) Published
Abstract [en]

The signaling data in cellular networks provide means for analyzing the use of transportation systems. We propose methods that aim to reconstruct the used route through a transportation network from call detail records (CDRs) which are spatially and temporally sparse. The route estimation methods are compared based on the individual routes estimated. We also investigate the effect of different route estimation methods when employed in a complete network assignment for a larger city. Using an available CDR dataset for Dakar, Senegal, we show that the choice of the route estimation method can have a significant impact on resulting link flows.

Place, publisher, year, edition, pages
Taylor & Francis, 2018
Keywords
Cellular network data, route estimation, network assignment
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-144541 (URN)10.1080/10630732.2017.1386939 (DOI)000437198100006 ()
Note

Funding agencies: Swedish Governmental Agency for Innovation Systems (VINNOVA)

Available from: 2018-01-26 Created: 2018-01-26 Last updated: 2018-07-27
Breyer, N., Gundlegård, D., Rydergren, C. & Bäckman, J. (2017). Trip extraction for traffic analysis using cellular network data. In: IEEE Italy Section (Ed.), 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems (MT-ITS): . Paper presented at Models and Technologies for Intelligent Transportation Systems (MT-ITS), 26-28 June 2017, Naples, Italy (pp. 321-326). Naples
Open this publication in new window or tab >>Trip extraction for traffic analysis using cellular network data
2017 (English)In: 5th IEEE International Conference on Models and Technologies for Intelligent Transportation Systems (MT-ITS) / [ed] IEEE Italy Section, Naples, 2017, p. 321-326Conference paper, Published paper (Refereed)
Abstract [en]

To get a better understanding of people’s mobility, cellular network signalling data including location information, is a promising large-scale data source. In order to estimate travel demand and infrastructure usage from the data, it is necessary to identify the trips users make. We present two trip extraction methods and compare their performance using a small dataset collected in Sweden. The trips extracted are compared with GPS tracks collected on the same mobiles. Despite the much lower location sampling rate in the cellular network signalling data, we are able to detect most of the trips found from GPS data. This is promising, given the relative simplicity of the algorithms. However, further investigation is necessary using a larger dataset and more types of algorithms. By applying the same methods to a second dataset for Senegal with much lower sampling rate than the Sweden dataset, we show that the choice of the trip extraction method tends to be even more important when the sampling rate is low. 

Place, publisher, year, edition, pages
Naples: , 2017
Keywords
Global Positioning System, cellular radio, data communication, telecommunication traffic, Sweden, cellular network data, signalling data, traffic analysis, trip extraction, Antennas, Cellular networks, Data mining, Global Positioning System, Google, History, Spatial resolution
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-140906 (URN)10.1109/MTITS.2017.8005688 (DOI)000426813700055 ()978-1-5090-6484-7 (ISBN)
Conference
Models and Technologies for Intelligent Transportation Systems (MT-ITS), 26-28 June 2017, Naples, Italy
Projects
MOFT
Funder
VINNOVA
Available from: 2017-09-15 Created: 2017-09-15 Last updated: 2018-04-20Bibliographically approved
Allström, A., Ekström, J., Gundlegård, D., Ringdahl, R., Rydergren, C., Bayen, A. M. & Patire, A. D. (2016). A hybrid approach for short-term traffic state and travel time prediction on highways. In: TRB 95th annual meeting compendium of papers: . Paper presented at Transportation Research Board 95th Annual Meeting, 2016-1-10 to 2016-1-14 Washington DC, United States.
Open this publication in new window or tab >>A hybrid approach for short-term traffic state and travel time prediction on highways
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2016 (English)In: TRB 95th annual meeting compendium of papers, 2016Conference paper, Published paper (Refereed)
Abstract [en]

Traffic management and traffic information are essential in urban areas, and require a good knowledge about both the current and the future traffic state. Both parametric and non-parametric traffic state prediction techniques have previously been developed, with different advantages and shortcomings. While non-parametric prediction has shown good results for predicting the traffic state during recurrent traffic conditions, parametric traffic state prediction can be used during non-recurring traffic conditions such as incidents and events. Hybrid approaches, combining the two prediction paradigms have previously been proposed by using non-parametric methods for predicting boundary conditions used in a parametric method. In this paper we instead combine parametric and non-parametric traffic state prediction techniques through assimilation in an Ensemble Kalman filter. As non-parametric prediction method a neural network method is adopted, and the parametric prediction is carried out using a cell transmission model with velocity as state. The results show that our hybrid approach can improve travel time prediction of journeys planned to commence 15 to 30 minutes into the future, using a prediction horizon of up to 50 minutes ahead in time to allow the journey to be completed.

National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-125386 (URN)
Conference
Transportation Research Board 95th Annual Meeting, 2016-1-10 to 2016-1-14 Washington DC, United States
Projects
Mobile Millenium Stockholm
Funder
TrenOp, Transport Research Environment with Novel Perspectives
Available from: 2016-02-22 Created: 2016-02-22 Last updated: 2016-06-03
Allström, A., Ekström, J., Gundlegård, D., Ringdahl, R., Rydergren, C., Bayen, A. M. & Patire, A. D. (2016). Hybrid Approach for Short-Term Traffic State and Travel Time Prediction on Highways. Transportation Research Record, 2554, 60-68
Open this publication in new window or tab >>Hybrid Approach for Short-Term Traffic State and Travel Time Prediction on Highways
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2016 (English)In: Transportation Research Record, ISSN 0361-1981, E-ISSN 2169-4052, Vol. 2554, p. 60-68Article in journal (Refereed) Published
Abstract [en]

Traffic management and traffic information are essential in urban areas and require reliable knowledge about the current and future traffic state. Parametric and nonparametric traffic state prediction techniques have previously been developed with different advantages and shortcomings. While nonparametric prediction has shown good results for predicting the traffic state during recurrent traffic conditions, parametric traffic state prediction can be used during nonrecurring traffic conditions, such as incidents and events. Hybrid approaches have previously been proposed; these approaches combine the two prediction paradigms by using nonparametric methods for predicting boundary conditions used in a parametric method. In this paper, parametric and nonparametric traffic state prediction techniques are instead combined through assimilation in an ensemble Kalman filter. For nonparametric prediction, a neural network method is adopted; the parametric prediction is carried out with a cell transmission model with velocity as state. The results show that the hybrid approach can improve travel time prediction of journeys planned to commence 15 to 30 min into the future, with a prediction horizon of up to 50 min ahead in time to allow the journey to be completed

Place, publisher, year, edition, pages
Washington, DC, USA: The National Academies of Sciences, Engineering, and Medicine, 2016
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-132632 (URN)10.3141/2554-07 (DOI)000388911900008 ()
Funder
TrenOp, Transport Research Environment with Novel Perspectives
Note

Funding agencies: Swedish Transport Administration

Available from: 2016-11-17 Created: 2016-11-17 Last updated: 2017-11-29Bibliographically approved
Olstam, J., Engelson, L., Johansson, L. & Rydergren, C. (2016). Nya restidsfunktioner med korsningsfördröjning. Linköping: Statens väg- och transportforskningsinstitut
Open this publication in new window or tab >>Nya restidsfunktioner med korsningsfördröjning
2016 (Swedish)Report (Other academic)
Alternative title[en]
New volume delay functions with intersection delay
Abstract [sv]

Denna rapport presenterar metod och resultat för framtagning av nya restidsfunktioner till trafikprognosverktyget Sampers. Restidsfunktioner innehåller en del som beskriver fördröjning på vägen och en del som beskriver fördröjningen i samband med korsningar. Då det är svårt och dyrt att göra samtidiga mätningar av trafikflöden och restider har en alternativ ansats använts där restidsfunktionerna kalibrerats baserat på beräkningar av korsningsfördröjning för olika korsningsutformningar med korsningsmodellen Capcal. De framtagna restidsfunktionerna har testats och validerats och är nu implementerade i Samperssystemet.

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.

Place, publisher, year, edition, pages
Linköping: Statens väg- och transportforskningsinstitut, 2016. p. 65
Series
VTI rapport, ISSN 0347-6030 ; 890
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-128100 (URN)
Available from: 2016-05-17 Created: 2016-05-17 Last updated: 2016-05-17Bibliographically approved
Connors, R., Patriksson, M., Rydergren, C., Sumalee, A. & Watling, D. (2015). Sensitivity Analysis of Welfare, Equity, and Acceptability Level of Transport Policies. In: Athanasios Migdalas, Athanasia Karakitsiou (Ed.), Optimization, Control, and Applications in the Information Age: In Honor of Panos M. Pardalos’s 60th Birthday (pp. 39-65). London: Springer Publishing Company
Open this publication in new window or tab >>Sensitivity Analysis of Welfare, Equity, and Acceptability Level of Transport Policies
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2015 (English)In: Optimization, Control, and Applications in the Information Age: In Honor of Panos M. Pardalos’s 60th Birthday / [ed] Athanasios Migdalas, Athanasia Karakitsiou, London: Springer Publishing Company, 2015, p. 39-65Chapter in book (Refereed)
Place, publisher, year, edition, pages
London: Springer Publishing Company, 2015
Series
Springer Proceedings in Mathematics & Statistics, ISSN 2194-1009
National Category
Computational Mathematics
Identifiers
urn:nbn:se:liu:diva-121273 (URN)10.1007/978-3-319-18567-5_3 (DOI)000380540400003 ()978-3-319-18566-8 (ISBN)978-3-319-18567-5 (ISBN)
Available from: 2015-09-10 Created: 2015-09-10 Last updated: 2016-08-19
Gundlegård, D., Rydergren, C., Barcelo, J., Dokoohaki, N., Hess, A. & Görnerup, O. (2015). Travel demand analysis with differential private releases. In: Vincent Blondel (Ed.), Netmob 2015: Mobile phone data for development. Paper presented at Netmob 2015 - Fourth International Conference on the Analysis of Mobile Phone Datasets, April 8-10, 2015, MIT, Cambridge, MA, USA.
Open this publication in new window or tab >>Travel demand analysis with differential private releases
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2015 (English)In: Netmob 2015: Mobile phone data for development / [ed] Vincent Blondel, 2015Conference paper, Published paper (Refereed)
Abstract [en]

The use of mobile phone data for planning of transport infrastructure has been shown to have great potential in providing a means of analyzing the efficiency of a transportation system and assisting in the formulation of transport models to predict its future use. In this paper we describe how this type of data can be processed and used in order to act as both enablers for traditional transportation analysis models, and provide new ways of estimating travel behavior. Specifically, we propose a technique for describing the travel demand by constructing time sliced origin destination matrices which respect the level of detail available in Call Detail Records (CDR) from mobile phone use.

When analyzing large quantities of human mobility traces, the aspects of sensitivity of traces to be analyzed, and the scale at which such analysis can be accounted for is of high importance. The sensitivity implies that identifiable information must not be inferred from the data or any analysis of it. Thus, prompting the importance of maintaining privacy during or post-analysis stages. We aggregate the raw data with the goal to retain relevant information while at the same time discard sensitive user specifics, through site sequence clustering and frequent sequence extraction. These techniques have at least three benefits: data reduction, information mining, and anonymization. Further, the paper reviews the aggregation techniques with regard to privacy in a post-processing step.

The approaches presented in the paper for estimation of travel demand and route choices, and the additional privacy analysis, build a comprehensive framework usable in the processing of mobile phone data for transportation planning.

The project presented in this paper a part of the D4D-Senegal challenge.

Keywords
Mobile phone, CDR, mobiity, travel demand, analytics
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-120997 (URN)
Conference
Netmob 2015 - Fourth International Conference on the Analysis of Mobile Phone Datasets, April 8-10, 2015, MIT, Cambridge, MA, USA
Available from: 2015-09-01 Created: 2015-09-01 Last updated: 2016-05-04
Allström, A., Bayen, A. M., Fransson, M., Gundlegård, D., Patire, A. D., Rydergren, C. & Sandin, M. (2014). Calibration Framework based on Bluetooth Sensors for Traffic State Estimation Using a Velocity based Cell Transmission Model. Paper presented at 17th Meeting of the EURO Working Group on Transportation, EWGT2014, 2-4 July 2014, Sevilla, Spain. Transportation Research Procedia, 3, 972-981
Open this publication in new window or tab >>Calibration Framework based on Bluetooth Sensors for Traffic State Estimation Using a Velocity based Cell Transmission Model
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2014 (English)In: Transportation Research Procedia, ISSN 2352-1465, Vol. 3, p. 972-981Article in journal (Refereed) Published
Abstract [en]

The velocity based cell transmission model (CTM-v) is a discrete time dynamical model that mimics the evolution of the traffic velocity field on highways. In this paper the CTM-v model is used together with an ensemble Kalman filter (EnKF) for the purpose of velocity sensor data assimilation. We present a calibration framework for the CTM-v and EnKF. The framework consists of two separate phases. The first phase is the calibration of the parameters of the fundamental diagram and the second phase is the calibration of demand and filter parameters. Results from the calibrated model are presented for a highway stretch north of Stockholm, Sweden.

Place, publisher, year, edition, pages
Elsevier, 2014
Keywords
Highway traffic modelling; calibration
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-112290 (URN)10.1016/j.trpro.2014.10.077 (DOI)000377412600103 ()
Conference
17th Meeting of the EURO Working Group on Transportation, EWGT2014, 2-4 July 2014, Sevilla, Spain
Available from: 2014-11-22 Created: 2014-11-22 Last updated: 2018-03-09Bibliographically approved
Ekström, J., Engelson, L. & Rydergren, C. (2014). Optimal Toll Locations and Levels in Congestion Pricing Schemes: a Case Study of Stockholm. Transportation planning and technology (Print), 37(4), 333-353
Open this publication in new window or tab >>Optimal Toll Locations and Levels in Congestion Pricing Schemes: a Case Study of Stockholm
2014 (English)In: Transportation planning and technology (Print), ISSN 0308-1060, E-ISSN 1029-0354, Vol. 37, no 4, p. 333-353Article in journal (Refereed) Published
Abstract [en]

As congestion pricing has moved from theoretical ideas in the literature to real world implementations, the need for decision support when designing the pricing schemes has become evident. This paper deals with the problem of finding optimal toll levels and locations in a road traffic network, and presents a case study of Stockholm. The optimization problem of finding optimal toll levels, given a predetermined cordon, and the problem of finding both optimal toll locations and levels are presented, and previously developed heuristics are used for solving these problems. For the Stockholm case study, the possible welfare gains of optimizing the toll levels in the current cordon, and optimizing both the toll locations and their corresponding toll levels are evaluated. It is shownthat by tuning the toll levels in the current congestion pricing cordon used in Stockholm, the welfare gain can be significantly increased, and furthermore improved by allowing a toll on the bypass highway “Essingeleden”. It is also shown that by optimizing both the toll locations and levels, a congestion pricing scheme with welfare gain close to what can be achieved by marginal social cost pricing, can be designed with tolls being located on only a forth of the tollable links.

Place, publisher, year, edition, pages
Routledge, 2014
Keywords
congestion pricing; road tolls; bilevel optimisation; user equilibrium; network design; Stockholm
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-76640 (URN)10.1080/03081060.2014.897129 (DOI)000334158100002 ()
Note

On the day of the defence date of the Thesis the status of this article was Manuscript.

Available from: 2012-04-13 Created: 2012-04-13 Last updated: 2017-12-07Bibliographically approved
Rydergren, C. (2013). Comparison of headway-based public transport models: Numerical experiments for Stockholm. Public Transport, 5(3), 177-191
Open this publication in new window or tab >>Comparison of headway-based public transport models: Numerical experiments for Stockholm
2013 (English)In: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 5, no 3, p. 177-191Article in journal (Refereed) Published
Abstract [en]

In this paper we evaluate the output from four headway-based public transport model variants for modeling the public transports in Stockholm, Sweden. The results from the four models are analyzed and compared to trip observations. The comparisons are based on model instances where the parameters in the generalized travel time function are calibrated. The best possible parameter values have been found using the calibration procedures SPSA and Compass search. Two different objective functions have been evaluated for the calibration.

Numerical experiments have been performed using a public transport model implemented in Visum by Storstockholms lokaltrafik. For the calibration and analysis, trip observations from the Swedish national travel survey and data generated from a public transport trip planner are used.

From the numerical results, it is concluded that it is of less importance to find the best possible parameter values in the generalized cost function than selecting the best model variant. For the Stockholm public transport model, the numerical results indicate that the models in the class of Random departure time models result in a better fit to the observed trips than the models in the class of Optimal strategies.

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2013
Keywords
Public transport, Headway-based, Assignment, Calibration
National Category
Other Engineering and Technologies
Identifiers
urn:nbn:se:liu:diva-102011 (URN)10.1007/s12469-013-0071-y (DOI)
Available from: 2013-11-26 Created: 2013-11-26 Last updated: 2017-12-06Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0001-6405-5914

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