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Lundgren, Jan T.
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Publications (10 of 26) Show all publications
Häll, C. H., Lundgren, J. T. & Voß, S. (2015). Evaluating the performance of a dial-a-ride service using simulation. Public Transport, 7(2), 139-157
Open this publication in new window or tab >>Evaluating the performance of a dial-a-ride service using simulation
2015 (English)In: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 7, no 2, p. 139-157Article in journal (Refereed) Published
Abstract [en]

In this paper we study the effects of changes to a paratransit system operated as a dynamic dial-a-ride service. The scheduling of requests is limited by time window constraints and maximum ride time constraints; costs for customer discomfort in form of waiting time and excess ride time are considered in the planning of the service. The parameters defining these constraints and costs are evaluated based on simulations of a real-world scenario. Several different criteria, both regarding customer level of service and operational costs, are used to evaluate the simulation results. By showing which parameters have a large impact on the different evaluation criteria, we can give guidelines to operators of public transport of how to design their dial-a-ride services. Numerical results are presented and from these results conclusions are drawn regarding which parameters are most important in dynamic dial-a-ride services.

Place, publisher, year, edition, pages
Springer Berlin/Heidelberg, 2015
Keywords
Dial-a-ride, Paratransit, Simulation
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:liu:diva-121361 (URN)10.1007/s12469-015-0101-z (DOI)
Available from: 2015-09-15 Created: 2015-09-15 Last updated: 2017-12-04Bibliographically approved
Häll, C. H., Högberg, M. & Lundgren, J. T. (2012). A modeling system for simulation of dial-a-ride services. Public Transport, 4(1), 17-37
Open this publication in new window or tab >>A modeling system for simulation of dial-a-ride services
2012 (English)In: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 4, no 1, p. 17-37Article in journal (Refereed) Published
Abstract [en]

We present a modeling system for simulation of dial-a-ride services. It can be used as a tool for understanding and study how different designs, and different ways to operate a dial-a-ride service, affect the performance and efficiency of the service. The system simulates the operation of a dynamic dial-a-ride service that operates with multiple fleets of vehicles with different capacities, schedules and depots. It can be used to investigate how the setting of service and cost parameters and the design of the service affect the total cost for the operator and level of service for the customer. We describe the different modules in the system and the possible uses of the system. A short simulation study is performed to exemplify how it can be used. In this study the effects of including costs for customer discomfort are evaluated.

Place, publisher, year, edition, pages
Berlin / Heidelberg: Springer, 2012
Keywords
dial-a-ride, optimization, public transport, simulation
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:liu:diva-68057 (URN)10.1007/s12469-012-0052-6 (DOI)
Available from: 2011-05-09 Created: 2011-05-09 Last updated: 2017-12-11Bibliographically approved
Häll, C. H., Lundgren, J. T. & Voss, S. (2012). Evaluating the performance of a dial-a-ride service using simulation. Paper presented at CASPT 12: Conference on Advanced Systems for Public Transport, 23-27 July 2012, Santiago, Chile.
Open this publication in new window or tab >>Evaluating the performance of a dial-a-ride service using simulation
2012 (English)Conference paper, Oral presentation only (Other academic)
Abstract [en]

In this paper we study the effects of changes to a paratransit system operated as a dynamic dial-a-ride service. The scheduling of requests is limited by time window constraints and maximum ride time constraints, and costs for customer discomfort in form of waiting time and excess ride time, are considered in the planning of the service. The parameters defining these constraints and costs are evaluated based on simulations of a real-world scenario.

Several different criteria, both regarding customer level of service and operational costs, are used to evaluate the simulation results. By showing what parameters that have a large impact on the different evaluation criteria, we can give guidelines to operators of public transport of how to design their dial-a-ride services. Numerical results are presented and from these results conclusions are drawn regarding what parameters are most important in dynamic dial-a-ride services.

Keywords
public transport, simulation, dial-a-ride
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:liu:diva-80072 (URN)
Conference
CASPT 12: Conference on Advanced Systems for Public Transport, 23-27 July 2012, Santiago, Chile
Available from: 2012-08-20 Created: 2012-08-20 Last updated: 2012-08-27
Olstam, J., Espié, S., Mårdh, S., Jansson, J. & Lundgren, J. (2011). An algorithm for combining autonomous vehicles and controlled events in driving simulator experiments. Transportation Research Part C: Emerging Technologies, 19(6), 1185-1201
Open this publication in new window or tab >>An algorithm for combining autonomous vehicles and controlled events in driving simulator experiments
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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
Allström, A., Archer, J., Bayen, A., Blandin, S., Butler, J., Gundlegård, D., . . . Tossavainen, O.-P. (2011). Mobile Millennium Stockholm. In: 2nd International Conference on Models and Technologies for Intelligent Transportation Systems. Paper presented at 2nd International Conference on Models and Technologies for Intelligent Transportation Systems, 22-24 June 2011, Leuven, Belgium.
Open this publication in new window or tab >>Mobile Millennium Stockholm
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2011 (English)In: 2nd International Conference on Models and Technologies for Intelligent Transportation Systems, 2011Conference paper, Published paper (Other academic)
Keywords
Traffic modelling, travel time estimation
National Category
Transport Systems and Logistics
Identifiers
urn:nbn:se:liu:diva-79777 (URN)
Conference
2nd International Conference on Models and Technologies for Intelligent Transportation Systems, 22-24 June 2011, Leuven, Belgium
Projects
Mobile Millennium Stockholm
Available from: 2012-08-14 Created: 2012-08-14 Last updated: 2016-05-04
Larsson, T., Lundgren, J. & Peterson, A. (2010). Allocation of Link Flow Detectors for Origin-Destination Matrix Estimation-A Comparative Study. COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, 25(2), 116-131
Open this publication in new window or tab >>Allocation of Link Flow Detectors for Origin-Destination Matrix Estimation-A Comparative Study
2010 (English)In: COMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, ISSN 1093-9687, Vol. 25, no 2, p. 116-131Article in journal (Refereed) Published
Abstract [en]

Origin-destination (OD) matrices are essential for various analyses in the field of traffic planning, and they are often estimated from link flow observations. We compare methods for allocating link flow detectors to a traffic network with respect to the quality of the estimated OD-matrix. First, an overview of allocation methods proposed in the literature is presented. Second, we construct a controlled experimental environment where any allocation method can be evaluated, and compared to others, in terms of the quality of the estimated OD-matrix. Third, this environment is used to evaluate and compare three fundamental allocation methods. Studies are made on the Sioux Falls network and on a network modeling the city of Linkoping. Our conclusion is, that the most commonly studied approach for detector allocation, maximizing the coverage of OD-pairs, seems to be unfavorable for the quality of the estimated OD-matrix.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-53695 (URN)10.1111/j.1467-8667.2009.00625.x (DOI)
Available from: 2010-02-01 Created: 2010-02-01 Last updated: 2018-08-23
Häll, C. H., Lundgren, J. T. & Peterson, A. (2009). Improving the efficiency of swedish paratransit: an application of the dial-a-ride problem. Paper presented at 23rd European conference on operational research, Bonn, July 5-8, 2009.
Open this publication in new window or tab >>Improving the efficiency of swedish paratransit: an application of the dial-a-ride problem
2009 (English)Conference paper, Published paper (Other academic)
Keywords
public transport, dial-a-ride, optimization
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:liu:diva-51821 (URN)
Conference
23rd European conference on operational research, Bonn, July 5-8, 2009
Available from: 2009-11-19 Created: 2009-11-19 Last updated: 2018-08-23
Häll, C. H., Andersson, H., Lundgren, J. T. & Värbrand, P. (2009). The Integrated Dial-a-Ride Problem. Public Transport, 1(1), 39-54
Open this publication in new window or tab >>The Integrated Dial-a-Ride Problem
2009 (English)In: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 1, no 1, p. 39-54Article in journal (Refereed) Published
Abstract [en]

In this paper we present a formulation of the Integrated Dial-a-Ride (IDARP). This problem is to schedule dial-a-ride requests, where some part of each journey may be carried out by a fixed route service. The IDARP is a generalization of the Dial-a-Ride Problem. An arc-based formulation is proposed, and it is shown how the model can be made easier to solve by arc elimination, variable substitution and the introduction of subtour elimination constraints. Small instances of the IDARP can be solved using an exact solution method, and one such instance is studied. We also describe how input and output data can be created and visualized in a geographic information system.

Place, publisher, year, edition, pages
Berlin / Heidelberg: Springer, 2009
Keywords
public transport, dial-a-ride, optimization, IDARP
National Category
Other Engineering and Technologies not elsewhere specified
Identifiers
urn:nbn:se:liu:diva-51818 (URN)10.1007/s12469-008-0006-1 (DOI)
Available from: 2009-11-19 Created: 2009-11-19 Last updated: 2017-12-12Bibliographically approved
Olstam, J., Lundgren, J., Adlers, M. & Matstoms, P. (2008). A Framework for Simulation of Surrounding Vehicles in Driving Simulators. ACM Transactions on Modeling and Computer Simulation, 18(3)
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
Lundgren, J. & Peterson, A. (2008). A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem. Transportation Research Part B: Methodological, 42(4), 339-354
Open this publication in new window or tab >>A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem
2008 (English)In: Transportation Research Part B: Methodological, ISSN 0191-2615, E-ISSN 1879-2367, Vol. 42, no 4, p. 339-354Article in journal (Refereed) Published
Abstract [en]

In this paper we consider the estimation of an origin–destination (OD) matrix, given a target OD-matrix and traffic counts on a subset of the links in the network. We use a general nonlinear bilevel minimization formulation of the problem, where the lower level problem is to assign a given OD-matrix onto the network according to the user equilibrium principle. After reformulating the problem to a single level problem, the objective function includes implicitly given link flow variables, corresponding to the given OD-matrix. We propose a descent heuristic to solve the problem, which is an adaptation of the wellknown projected gradient method. In order to compute a search direction we have to approximate the Jacobian matrix representing the derivatives of the link flows with respect to a change in the OD-flows, and we propose to do this by solving a set of quadratic programs with linear constraints only. If the objective function is differentiable at the current point, the Jacobian is exact and we obtain a gradient. Numerical experiments are presented which indicate that the solution approach can be applied in practice to medium to large size networks.

Place, publisher, year, edition, pages
Institutionen för teknik och naturvetenskap, 2008
Keywords
Origin-Destination matrix; Sensitivity analysis; User-equilibrium
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-11461 (URN)10.1016/j.trb.2007.09.005 (DOI)
Note
Original publication: Jan T Lundgren and Anders Peterson, A Heuristic for the Bilevel Origin–Destination Matrix Estimation Problem, 2008, Transportation Research Part B: Methodological, (42), 4, 339-354. http://dx.doi.org/10.1016/j.trb.2007.09.005. Copyright: Elsevier B.V., http://www.elsevier.com/Available from: 2008-04-03 Created: 2008-04-03 Last updated: 2018-08-23
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