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Data regarding Swiss Railways 1847-1920
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Frontiers in Transportation
Social Networks and Travel
IATBR
International Association for Travel Behaviour Research
MATSIM-T
Multi-agent transport simulation-toolkit
MobiDrive
A six-week travel diary
OpenTrack / OpenTimetable
Simulation of Railway Systems and Timetable Analysis
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A Trans-Discplinary Multi-Dimensional Simulation
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Swiss Transport Research Conference
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, Waraich, Rashid A., Charypar, David, Balmer, Michael, Axhausen, Kay W., 2015 >>
Author(s): Waraich, Rashid A., Charypar, David, Balmer, Michael, Axhausen, Kay W.
Title: Performance improvements for large-scale traffic simulation in MATSim
Abstract: In contrast to aggregated macroscopic models of traffic simulation, multi-agent microscopic models, such as MATSim, enable modeling of individual behavior and facilitate more detailed traffic analysis. However, such detailed modeling also leads to an increased computational burden, such that simulation performance becomes critical.

This paper looks specifically at theMATSim simulation framework and proposes several ways to improve its performance. This is achieved through a combination of several approaches, including reducing disk access, decoupling computational tasks, and making use of parallel computing. Additionally, for the traffic simulation, an event-based model is adopted instead of a fixed-increment time advance approach.

Experiments show that by applying these methods, a simulation speedup of four times and more is achieved (depending on the scenario) when compared to the current Java micro-simulation in MATSim.

Initial simulation experiments on a high-resolution navigation network of Switzerland – containing around one million roads and 7.3 million agents – demonstrate that real-world scenarios can now be executed in around one-anda- half weeks using the improved model. Ways to further shorten the computational time of MATSim are also described.2
Book title: Computational Approaches for Urban Environments
Published in: Geotechnologies and the Environment
Volume: 13
Pages: 211 - 233
ISBN: 978-3-319-11468-2, 978-3-319-11469-9
Publication date / Date received: 2015-01-01
Publication status: Cham
Publication status: Published
Subjects: Large-scale traffic simulation, Agent based modeling, Parallelization
Language: English
Keyword: Large-scale traffic simulation, Agent based modeling, Parallelization
DBID source: FORM-1425653099, WOS-000357510900010, SCOPUS-84943785656
DOI: 10.1007/978-3-319-11469-9_9
, Janzen, Maxim, Charypar, David, Axhausen, Kay W., 2014 >>
Author(s): Janzen, Maxim, Charypar, David, Axhausen, Kay W.
Title: Long Term Simulation of a Continuous Target-Based Model
Abstract: To date, travel demand generation for microscopic traffic flow simulation focuses mostly on reproducing daily life behavior. This stands in contrast to the significant part of traffic volume caused by journeys related to activities not usually undertaken in daily life. The paper investigates the possibilities of extending an existing approach (continuous target-based planning) to cover some of these exceptional activities. This paper discusses the possibilities to extend the continuous target-based approach in order to generate long term travel demand including journeys which are not part of daily life (e.g. going on holidays). The proposed extensions include new low-frequenced targets with higher travel times than daily life targets. Consequences and the necessary adaptions of the heuristics used arising from these special targets are presented here.2
Publication date / Date received: 2014-05-01
Publication status: Ascona
Publication status: Published
Subjects: Continuous target based model, Long term simulation, Long distance travel demand, Microscopic travel demand simulation, C-TAP
Event name: 14th Swiss Transport Research Conference (STRC 2014)
Event date: May 14-16, 2014
Place: Monte Verità, Ascona, Switzerland
Language: English
Keyword: Continuous target based model, Long term simulation, Long distance travel demand, Microscopic travel demand simulation, C-TAP
DBID source: FORM-1400087848
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2014 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Location choice for a continuous simulation of long periods under changing conditions
Abstract: The authors propose a location choice procedure that is capable of handling changing conditions of aspects with different time horizons. It integrates expected travel time, current location effectiveness, prospective location effectiveness, and individual unexplained location perception into a decision heuristic that considers different planning horizons simultaneously and decides on-the-fly about future location visits. Multiple simulation runs illustrate agents' location choice behavior in various situations and confirm that the model enables agents to simultaneously consider seasonal effects, weather conditions, expected travel times, and individual unexplained location preference in their location choice.
Published in: Journal of transport and land use
Volume: 7
Issue: 2
Pages: 1 - 17
ISSN: 1938-7849
Publication date / Date received: 2014-01-01
Publication status: Minneapolis, MN
Publication status: Published
Subjects: Location choice, Multi-week schedules, Continuous activity generation and scheduling, Microscopic travel demand simulation, Continuous target-based activity planning (C-TAP)
Language: English
Keyword: Location choice, Multi-week schedules, Continuous activity generation and scheduling, Microscopic travel demand simulation, Continuous target-based activity planning (C-TAP)
DBID source: FORM-1393411552
DOI: 10.5198/jtlu.v7i2.547
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2014 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Agent-based model for continuous activity planning with an open planning horizon
Abstract: The paper proposes a microscopic travel demand model that generates multi-week schedules by means of a continuous planning approach with an open planning horizon. This model introduces behavioral targets to describe people's motivation to perform activities, and it uses a planning heuristic to make on-the-fly decisions about upcoming activities. The planning heuristic bases its decisions on three aspects: a dis- 13 comfort index derived from deviations from agents' past performance with regard to their behavioral targets; the effectiveness of the immediate execution; and activity execution options available in the near future. The paper reports the results of a test scenario based on 16 an existing 6-week continuous travel diary and validates the model by comparing simulation results with observed behavioral patterns along several dimensions (weekday similarities, weekday execution probabilities of activities, transition probabilities between activities, duration distributions of activities, frequency distributions of activities, execution interval distributions of activities and weekly travel probability distributions). The results show that the model has the capability to reproduce observed behavior and the flexibility to introduces new behavioral patterns.
Published in: Transportation
Volume: 41
Issue: 4
Pages: 905 - 922
ISSN: 0049-4488, 1572-9435
Publication date / Date received: 2014-01-01
Publication status: Heidelberg
Publication status: Published
Subjects: Wirtschaft, Recht und Politik allgemein|Economics, Law and Politics, General, Continuous activity planning, Multi-week schedules, Multi-week diary validation, Microscopic travel demand simulation, Continuous target-based activity planning (C-TAP)
Language: English
Keyword: Continuous activity planning, Multi-week schedules, Multi-week diary validation, Microscopic travel demand simulation, Continuous target-based activity planning (C-TAP)
DBID source: FORM-1391763969, WOS-000338841000012
DOI: 10.1007/s11116-014-9512-y
Nebis system number: 000056550
, Charypar, David, 2014 >>
Author(s): Charypar, David
Title: PISim: A Parallelization Framework for Interaction Simulations
Abstract: This paper presents PISim, a Parallelization framework for Interaction Simulations. PISim can be used to simulate models of short ranged object interactios in space on high-performance computers. By using PISim, users can avoid the difficulties and complexity usually involved in porting sequential sourcecode to parallel machines. The framework achieves this by combining severals fast and simple elements: First, it uses an efficient representation of space (a helical array) which exploits temporal continuity, second, it uses a straightforward way of communica- tion between processors by means of message passing, third, it arranges simulation domains in cell clusters that are treated as individual objects, fourth, it monitors the computation times of each cluster continuously and uses model based control to grow or shrink the clusters as needed to balance the load between processors, and fifth, it encapsulates and hides all this complexity from the user by using programming templates to provide a slim interface for end users. This small interface makes it possible to adopt the framework easily to new problems. It quickens development cyles and therby enables users not familiar with parallel programming techniques to adapt rapid prototyping paradigms.
Published in: Arbeitsberichte Verkehrs- und Raumplanung
Volume: 985
Publication date / Date received: 2014-01-01
Publication status: Zürich
Publication status: Published
Subjects: Parallelization, Software Framework, Simulation
Language: English
Keyword: Parallelization, Software Framework, Simulation
DBID source: FORM-1397801033
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2013 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Integration of Household Interaction with a Continuous Simulation Model
Abstract: This paper presents an approach to integrate social interactions with a agent based simulation model for continuous activity planning. It describes an interface to the underlying target-based model providing the possibility to influence agents' behavior by manipulating targets and effectiveness functions. It proposes tasks as the mean for exogenous modules to interact with agents and describes a module for managing social interactions among agents. This module uses the interface to ensure agents adhere to appointments and meet at arranged locations and specified dates. The validation of the approach focuses on activities shared among household members requiring regular meetings to arrange future responsibilities. We conclude by suggesting directions for future research.
Publication date / Date received: 2013-01-01
Publication status: Published
Event name: 13th Swiss Transport Research Conference (STRC 2013)
Event date: April 24-26, 2013
Place: Ascona, Switzerland
Language: English
DBID source: FORM-1367322920
, Charypar, David, Axhausen, Kay W., 2013 >>
Author(s): Charypar, David, Axhausen, Kay W.
Title: A Framework for Parallel Agent-Based Simulation in Physical Space
Publication date / Date received: 2013-01-01
Publication status: Published
Event name: 13th Swiss Transport Research Conference (STRC 2013)
Event date: April 24-26, 2013
Place: Ascona, Switzerland
Language: English
DBID source: FORM-1367316646
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2012 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Location Choice in a Continuous Model
Abstract: This paper proposes a location choice procedure that is capable to handle long term and continuous location choice aspects. It integrates expected travel time, current location effectiveness, prospective location effectiveness, and individual unexplained location preference into a target-based model whose decision heuristic decides on the fly and with an open time horizon about future locations agents should visit. Several simulation runs illustrate agents' location choice behavior in different situations. We conclude by suggesting directions for future research.2
Publication date / Date received: 2012-07-01
Publication status: Zürich
Publication status: Published
Subjects: Angewandte Informatik, Künstliche Intelligenz|Applied Computer Science, Artificial Intelligence, Location choice, Seasonal effects, Continuous model, Multiday schedules, Continuous activity generation and scheduling, Microscopic travel demand simulation
Event name: 13th International Conference on Travel Behaviour Research
Event date: July 15-20, 2012
Place: Toronto, Ontario, Canada
Language: English
Keyword: Location choice, Seasonal effects, Continuous model, Multiday schedules, Continuous activity generation and scheduling, Microscopic travel demand simulation
DBID source: FORM-1339747144
DOI: 10.3929/ethz-a-007313488
Nebis system number: 007313488
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2012 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Validation of a Continuous Simulation Model for Daily Travel
Abstract: This paper validates a microscopic travel demand simulation that employs a continuous planning approach with an open time horizon. It uses behavioral targets to model people's motivation to execute activities. People's behavior originates from a planning heuristic making on the fly decisions about upcoming activities. The planning heuristic bases its decisions on the available activity execution options in the near planning future, its current execution effectiveness and on a discomfort measure derived from deviations between people's performance and their behavioral targets. We validate the model and illustrate its features through three model configurations and suggest directions for future research.2
Publication date / Date received: 2012-01-01
Publication status: Zürich
Publication status: Published
Subjects: Validation of target-based model, Continuous activity generation and scheduling, Microscopic travel demand simulation
Event name: 12th Swiss Transport Research Conference (STRC 2012)
Event date: May 2-4, 2012
Place: Ascona, Switzerland
Language: English
Review status: Peer reviewed
Keyword: Validation of target-based model, Continuous activity generation and scheduling, Microscopic travel demand simulation
DBID source: FORM-1335778317
DOI: 10.3929/ethz-a-007250963
Nebis system number: 007250963
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2012 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Target Driven Activity Planning
Publication date / Date received: 2012-01-01
Publication status: Washington, D.C.
Publication status: Published
Event name: 91st Annual Meeting of the Transportation Research Board
Event date: January 22-26, 2012
Place: Washington, D.C.
Language: English
Review status: Peer reviewed
DBID source: FORM-1327670629
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2012 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Target Driven Activity Planning
Abstract: This paper proposes a microscopic travel demand simulation that employs a continuous planning approach with an open time horizon. It uses behavioral targets and the concept of projects to model people's motivation to execute activities. People's behavior originates from a planning heuristic making on the fly decisions about upcoming activities. The planning heuristic bases its decisions on the available activity execution options in the near planning future, its current execution eectiveness and on a discomfort measure derived from deviations between people's performance and their behavioral targets. We illustrate the model through several examples and suggest directions for future research.
Publication date / Date received: 2012-01-01
Publication status: Washington, D.C.
Publication status: Published
Event name: 91st Annual Meeting of the Transportation Research Board
Event date: January 22-26, 2012
Place: Washington, D.C., USA
Language: English
Review status: Peer reviewed
DBID source: FORM-1314265917
Nebis system number: 004231702
, Horni, Andreas, Charypar, David, Axhausen, Kay W., 2011 >>
Author(s): Horni, Andreas, Charypar, David, Axhausen, Kay W.
Title: Variability in Transport Microsimulations Investigated With the Multi-Agent Transport Simulation MATSim
Abstract: Transport microsimulations are stochastic. Randomness is, for example, introduced by the error terms of discrete choice models, a common component in utility-based microsimulations. This leads to random variability in results at all resolution levels. This paper's objectives is an analysis of this variability. As a very common and important aggregate measure in transport planning network link volumes are analyzed, based on MATSim simulation experiments. Constrained by modeling and simulation costs, recent large-scale, high-resolution microsimulations are cross-sectional models. When looking at aggregate levels relevant to planning, for common statistics there is relatively little variability over multiple simulation runs. However, these models do not properly account for temporal variability. This is problematic because temporal variability measured in reality is substantial. Thus, considering extension of these cross-sectional microsimulation models to longitudinal models will be necessary in the near future. To support this, the paper also documents first insights about temporal variability and temporal correlations in microsimulations.2
Published in: Arbeitsberichte Verkehrs- und Raumplanung
Volume: 692
Publication date / Date received: 2011-08-01
Publication status: Zürich
Publication status: Published
Language: English
Review status: Internally reviewed
DBID source: FORM-1312118663
DOI: 10.3929/ethz-a-006686329
Nebis system number: 006686329
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2011 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: A Continuous Simulation Concept for Daily Travel
Abstract: This paper proposes a microscopic traffic simulation that employs a continuous planning approach together with an open time horizon. It uses behavioral guidelines and the concept of projects to model people's motivation to execute activities. People's behavior originates from a planning heuristic making on the fly decisions about upcoming activities. The planning heuristic bases its decisions on the available activity options in the near planning future and on a discomfort measure which is derived from deviations between people's performance and their behavioral guidelines.2
Published in: Arbeitsberichte Verkehrs- und Raumplanung
Volume: 679
Publication date / Date received: 2011-05-01
Publication status: Zürich
Publication status: Published
Subjects: Behavioral guidelines, Personal projects, Continuous activity generation, Open time horizon, Microscopic traffic simulation
Event name: 11th Swiss Transport Research Conference (STRC 2011)
Event date: May 11-14, 2011
Place: Ascona, Switzerland
Language: English
Review status: Peer reviewed
Keyword: Behavioral guidelines, Personal projects, Continuous activity generation, Open time horizon, Microscopic traffic simulation
DBID source: FORM-1305894902
DOI: 10.3929/ethz-a-006467078
Nebis system number: 006467078
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2011 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Continuous activity planning for continuous traffic simulation
Abstract: This paper introduces a microscopic traffic simulation that continuously simulates activity-based agent behavior. Rather than using iterative optimization, which builds on stochastic user equilibria, the simulation uses a continuous planning approach. This approach's behavioral model uses the concept of needs to model human demands. Several intuitive parameters control demand and facilitate calibration of various behaviors. These behaviors originate from a planning heuristic making just-in-time decisions about upcoming activities that an agent should execute. The planning heuristic bases its decisions on agents' current need levels and their short-term development. The model is illustrated through simulation runs, and directions for future research are suggested.
Published in: Transportation research record
Issue: 2230
Pages: 29 - 37
ISSN: 0361-1981
Publication date / Date received: 2011-01-01
Publication status: Washington, D.C.
Publication status: Published
Language: English
Review status: Peer reviewed
DBID source: FORM-1323691539, WOS-000299066900004
DOI: 10.3141/2230-04
Nebis system number: 000024408
, Horni, Andreas, Charypar, David, Axhausen, Kay W., 2011 >>
Author(s): Horni, Andreas, Charypar, David, Axhausen, Kay W.
Title: Variability in transport microsimulations investigated for MATSim
Subtitle: Preliminary results
Abstract: As part of the recent integration of destination choices for discretionary activities, mechanisms to explicitly treat unobserved heterogeneity in MATSim were developed. This potentially introduced a large amount of randomness to the model as so far the MATSim utility function was deterministic. Adding randomness to a model clearly makes necessary variability analysis. In this paper first steps in assessing the variability of MATSim results are undertaken. The results are preliminary and need comprehensive verification and elaboration.2
Publication date / Date received: 2011-01-01
Publication status: Published
Event name: 11th Swiss Transport Research Conference (STRC 2011)
Event date: May 11-14, 2011
Place: Ascona, Switzerland
Language: English
DBID source: FORM-1334047839
DOI: 10.3929/ethz-a-006482318
Nebis system number: 006482318
, Horni, Andreas, Charypar, David, Axhausen, Kay W., 2011 >>
Author(s): Horni, Andreas, Charypar, David, Axhausen, Kay W.
Title: Investigating Variability in Transport Microsimulations Focussed on MATSim
Publication date / Date received: 2011-01-01
Publication status: Published
Event name: 11th Swiss Transport Research Conference (STRC 2011)
Event date: May 11-14, 2011
Place: Ascona, Switzerland
Language: English
Review status: Unknown
DBID source: FORM-1305893927
, Charypar, David, Märki, Fabian, Axhausen, Kay W., 2011 >>
Author(s): Charypar, David, Märki, Fabian, Axhausen, Kay W.
Title: Integrating two Simulation Modules with a General Parallelization Framework
Abstract: This paper describes a pedestrian walking simulator coupled with a simple destination choice model. First, a straight forward implementation is presented together with some performance figures. Afterwards, we discuss efficiency issues and describe several improvements in the al- gorithms and data structures employed. These improvements are based on the concept of a simulation framework that imposes limitation on the communication range and speed of the simulated entities (i.e. walking agents). As we discuss in the paper, these limitations speed up the computations necessary to simulate the interaction between virtual persons. The result- ing implementation shows clear performance gains and will simplify the final parallelization process of the simulation.2
Published in: Arbeitsberichte Verkehrs- und Raumplanung
Volume: 675
Publication date / Date received: 2011-01-01
Publication status: Zürich
Publication status: Published
Subjects: Transport simulation, Framework, Concept, Microsimulation, Integrated model
Event name: 11th Swiss Transport Research Conference (STRC 2011)
Event date: May 11-13, 2011
Place: Ascona, Switzerland
Language: English
Review status: Peer reviewed
Keyword: Transport simulation, Framework, Concept, Microsimulation, Integrated model
DBID source: FORM-1334048110
DOI: 10.3929/ethz-a-006482265
Nebis system number: 006482265
, Charypar, David, Märki, Fabian, Axhausen, Kay W., 2011 >>
Author(s): Charypar, David, Märki, Fabian, Axhausen, Kay W.
Title: Integrating two Simulation Modules with a General Parallelization Framewor
Published in: paper presented at the 11th Swiss Transport Research Conference
Publication date / Date received: 2011-01-01
Publication status: Published
Event name: 11th Swiss Transport Research Conference (STRC 2011)
Event date: May 11-14, 2011
Place: Ascona, Switzerland
Language: English
Review status: Unknown
DBID source: FORM-1305893707
, Charypar, David, 2011 >>
Author(s): Charypar, David
Title: Transport and Spatial Planning @ IVT
Publication date / Date received: 2011-01-01
Publication status: Published
Event name: Study Tour on Rail Transport in Switzerland
Event date: September 15, 2011
Place: Zürich, Switzerland
Language: English
Review status: Unknown
DBID source: FORM-1317051554
, Märki, Fabian, Charypar, David, Axhausen, Kay W., 2010 >>
Author(s): Märki, Fabian, Charypar, David, Axhausen, Kay W.
Title: Continuous Activity Planning for a Continuous Traffic Simulation
Abstract: 2
Publication date / Date received: 2010-01-01
Publication status: Published
Event name: 90th Annual Meeting of the Transportation Research Board
Event date: January 2011
Place: Washington, D.C., USA
Language: English
Review status: Peer reviewed
DBID source: FORM-1281361589
DOI: 10.3929/ethz-a-006127785
Nebis system number: 004231702
, Horni, Andreas, Charypar, David, Axhausen, Kay W., 2010 >>
Author(s): Horni, Andreas, Charypar, David, Axhausen, Kay W.
Title: Empirically approaching destination choice set formation
Abstract: The discrete choice modeling framework plays a dominant role in travel demand modeling. It is particularly suitable for choices with a compact choice set, such as mode choices. However, for spatial choices such as route or destination choices, which are in general characterized by a large number of alternatives, the choice set formation step poses crucial and to date unsolved methodological and empirical problems. In this paper, steps towards solving these important problems are introduced. The core of this paper is a publicly available Web-based survey tool that enables an empirical approach to destination choice set formation and that also has potential use in collaborative efforts. A detailed analysis of the problems associated with destination choice set formation and first approaches for model estimation are included.
Published in: Arbeitsberichte Verkehrs- und Raumplanung
Volume: 641
Publication date / Date received: 2010-01-01
Publication status: Published
Subjects: Raumordnung, Städtebau, Landschaftsarchitektur|Spatial and Urban Planning, Landscape Architecture, Verkehrsplanung, Strassen- und Eisenbahnbau|Traffic, Highway and Railroad Engineering, Verkehr und Transport|Traffic and Transportation, Shopping destination choice, Choice set formation
Event name: 90th Annual Meeting of the Transportation Research Board
Event date: January 23-27, 2011
Place: Washington, DC, USA
Language: English
Review status: Internally reviewed
Keyword: Shopping destination choice, Choice set formation
DBID source: FORM-1281361129
Nebis system number: 004231702
, Charypar, David, Horni, Andreas, Axhausen, Kay W., 2010 >>
Author(s): Charypar, David, Horni, Andreas, Axhausen, Kay W.
Title: Pushing the limits
Subtitle: A concept of a parallel microsimulation framework
Abstract: This paper describes the concept of a versatile transport simulation framework to be used for the development of integrated transport simulation models. It is designed to improve modularization and thereby simplify the collaboration between scientists and engineers from different fields. Modularization is believed to be important due to the increasing complexity of the implementation task if models from different areas are to be integrated. In performance critical software projects this complexity is often further increased by the desire or the need for an implementation that can be run in parallel on multiple processors. Furthermore, developing an efficient parallel simulation is not trivial. In addition to the complexity of the modeling task as such one has to deal with communication delays and data availability issues. The idea of the presented framework is to handle this complexity by defining simple rules according to which user developed modules must act. These rules include certain minimum delays between the observation of a change in the system and the triggered reactions, limited vision, and limited traveling speed. To illustrate how the framework is to be used a simples modeling scenario is created and a possible implementation employing the framework is sketched. The example scenario consists of the integration of a pedestrian simulation with a load estimation module and a travel time estimator. Finally, an outlook on the next steps in the development of the framework is given.
Published in: Arbeitsberichte Verkehrs- und Raumplanung
Volume: 640
Publication date / Date received: 2010-01-01
Publication status: Zürich
Publication status: Published
Subjects: Raumordnung, Städtebau, Landschaftsarchitektur|Spatial and Urban Planning, Landscape Architecture, Verkehrsplanung, Strassen- und Eisenbahnbau|Traffic, Highway and Railroad Engineering, Verkehr und Transport|Traffic and Transportation
Language: English
Review status: Internally reviewed
DBID source: FORM-1281361454
Nebis system number: 004231702
, Charypar, David, Horni, Andreas, Axhausen, Kay W., 2010 >>
Author(s): Charypar, David, Horni, Andreas, Axhausen, Kay W.
Title: Pushing the Limits
Subtitle: A Concept of a Parallel Microsimulation Framework
Abstract: This paper describes the concept of a versatile transport simulation framework to be used for the development of integrated transport simulation models. It is designed to improve modularization and thereby simplify the collaboration between scientists and engineers from different fields. Modularization is believed to be important due to the increasing complexity of the im plementation task if models from different areas are to be integrated. In performance critical software projects this complexity is often further increased by the desire or the need for an implementation that can be run in parallel on multiple processors. Furthermore, developing an efficient parallel simulation is not trivial. In addition to the complexity of the modeling task as such one has to deal with communication delays and data availability issues. The idea of the presented framework is to handle this complexity by defining simple rules according to which user developed modules must act. These rules include certain minimum delays between the observation of a change in the system and the triggered reactions, limited vision, and limited traveling speed. To illustrate how the framework is to be used a simples modeling scenario is created and a possible implementation employing the framework is sketched. The example scenario consists of the integration of a pedestrian simulation with a load estimation module and a travel time estimator. Finally, an outlook on the next steps in the development of the framework is given.
Published in: Arbeitsberichte Verkehrs- und Raumplanung
Volume: 640
Publication date / Date received: 2010-01-01
Publication status: Zürich
Language: English
DBID source: FORM-1286059642
, Balmer, Michael, Rieser, Marcel, Meister, Konrad, Charypar, David, Lefebvre, Nicolas, Nagel, Kai, 2009 >>
Author(s): Balmer, Michael, Rieser, Marcel, Meister, Konrad, Charypar, David, Lefebvre, Nicolas, Nagel, Kai
Title: MATSim-T
Subtitle: Architecture and simulation times
Book title: Multi-agent systems for traffic and transportation engineering
Pages: 57 - 78
ISBN: 978-1-60566-226-8, 1-60566-226-7, 978-1-60566-227-5, 1-60566-227-5
Publication date / Date received: 2009-01-01
Publication status: Hershey, PA
Publication status: Published
Subjects: Computeranwendungen|Computer Applications
Language: English
Review status: Peer reviewed
DBID source: PP-51058
DOI: 10.4018/978-1-60566-226-8.ch003
Nebis system number: 005824633
, Balmer, M., Charypar, D., Horni, A., Meister, K., 2009 >>
Author(s): Balmer, M., Charypar, D., Horni, A., Meister, K.
Title: Effect analysis of changes in travel behavior
Subtitle: Real world case studies with a large-scale micro-simulation
Publication date / Date received: 2009-01-01
Publication status: Published
Event name: 12th International Conference on Travel Behaviour Research
Event date: December 13-16, 2009
Place: Jaipur, India
Language: English
Review status: Unknown
DBID source: FORM-1305909906
, Charypar, David, Balmer, Michael, Axhausen, Kay W., 2008 >>
Author(s): Charypar, David, Balmer, Michael, Axhausen, Kay W.
Title: A high-performance traffic flow microsimulation for large problems
Abstract: Traffic flow microsimulations are interesting for transport planning problems due to their high temporal and spatial resolution. Unfortunately, most of them involve high computational costs making them impractical for running large scale scenarios. In this paper, we present how we extend our previous event-driven queue-based mircosimulation to run efficiently on parallel computers. Using appropriate load balancing and minimizing communication interfaces, we are able to simulate a test scenario involving 7 million simulated person days on a road network with 28k links in 87 seconds on 64 CPUs. Furthermore, we add support for signaled intersections that makes the model well suited for application to urban street networks. Finally, we show that our resulting model reproduces a reasonable relation between traffic flow and density similar to fundamental diagrams extracted from real world counts data.
Published in: Working paper / IVT
Volume: 509
Publication date / Date received: 2008-01-01
Publication status: Zürich
Publication status: Published
Subjects: Verkehrsplanung, Strassen- und Eisenbahnbau|Traffic, Highway and Railroad Engineering, Traffic flow microsimulation, Event driven simulation, Parallelization, Green time fractions, Large-scale scenario
Language: English
Review status: Peer reviewed
Keyword: Traffic flow microsimulation, Event driven simulation, Parallelization, Green time fractions, Large-scale scenario
DBID source: PP-51219, PP-41314
DOI: 10.3929/ethz-a-005652298
Nebis system number: 005652298
, Charypar, David, 2008 >>
Author(s): Charypar, David
Title: Efficient algorithms for the microsimulation of travel behavior in very large scenarios
Abstract: 2
Publication date / Date received: 2008-01-01
Publication status: Zürich
Publication status: Published
Subjects: Computeranwendungen|Computer Applications
Language: English
Review status: Peer reviewed
ETH dissertation number: 18034
DBID source: FORM-1314609845
DOI: 10.3929/ethz-a-005784752
Nebis system number: 005784752
, Balmer, Michael, Rieser, Marcel, Meister, Konrad, Charypar, David, Lefebvre, Nicolas, Nagel, Kai, Axhausen, Kay W., 2008 >>
Author(s): Balmer, Michael, Rieser, Marcel, Meister, Konrad, Charypar, David, Lefebvre, Nicolas, Nagel, Kai, Axhausen, Kay W.
Title: MATSim-T
Subtitle: Architektur und Rechenzeiten
Abstract: Traditionell werden in der Verkehrsplanung Meso- und Makro-Simulationen angewandt. Dies hat verschiedene Gründe. Einerseits sind die Datengrundlagen typischerweise aggregierter Natur, wie zum Beispiel Strassenzählungen oder Pendlermatrizen, andererseits waren die Rechenleistungen ungenügend, um detaillierte und demzufolge speicher- und prozessorintensive Berechnungen durchzuführen. Diese Grenzen haben sich in den letzten Jahren auf imposante Weise verschoben. In der Informationstechnik ist kontinuierlich ein exponentielles Wachstum derRechenkapazität zu einem beliebigen festen Preis zu beobachten. Hand in Hand mit dieser Entwicklung sind die Fragestellungen und Datengrundlagen in der Verkehrsplanung komplexerund detaillierter geworden. Es entstehen somit ganz neue Ansprüche an die Verkehrsplanungssoftware. Derzeit gewinnt die Mikrosimulation der Verkehrsnachfrage immer mehr an Bedeutung. Die wichtigsten Gründe dafür sind: Verringerter Rechenaufwand und Speicherbedarf von grossen, mehrdimensionalen Wahrscheinlichkeitsmatrizen Variationsreichere Ausgabeoptionen, von aggregierten statistischen Analysen bis hin zu detaillierten Informationen über einzelne Individuen eines Szenarios Explizites Modellieren des Entscheidungsfindungsprozesses jedes einzelnen Individuums In dieser Arbeit wird eine solche Agenten-Simulation für die Verkehrsplanung vorgestellt. Die Arbeit ist Teil des Forschungsprojektes MATSim-T (Multi-Agent Transport Simulation Toolkit, http://www.matsim.org) und konzentriert sich auf Design- und Implementationsfragen des Systems, sowie auf die Rechenzeiten der einzelnen Teile des Toolkits.Anhand des Anwendungsfalls der gesamt-schweizerischen Nachfrage (ca. 2.3 Mio. Individuen für den motorisierten Individualverkehr mit gesamthaft etwa 7.1 Mio. Wege auf dem nationalen Netzmodell mit ca. 60'000 Kanten, vollständig zeit-dynamisch simuliert und optimiert für einen durchschnittlichen Werktag) wird gezeigt, dass MATSim-T den den Verkehr in ca. 36 Stunden modelliert.2
Book title: HEUREKA '08, Optimierung in Verkehr und Transport
Published in: FGSV ; 002/90
Issue: 486
Pages: 1 - 27
ISBN: 978-3-939715-48-1
Publication date / Date received: 2008-01-01
Publication status: Zürich
Publication status: Published
Subjects: Verkehrsplanung, Strassen- und Eisenbahnbau|Traffic, Highway and Railroad Engineering, Computeranwendungen|Computer Applications, Verkehr und Transport|Traffic and Transportation
Event name: Heureka 2008
Event date: March 5-6, 2008
Place: Stuttgart, Germany
Language: German
Review status: Peer reviewed
DBID source: PP-41312
DOI: 10.3929/ethz-a-005564902
Nebis system number: 005564902
, Charypar, David, Axhausen, Kay W., Nagel, Kai, 2007 >>
Author(s): Charypar, David, Axhausen, Kay W., Nagel, Kai
Title: Event-driven queue-based traffic flow microsimulation
Abstract: Simulating traffic flow is an important problem in transport planning. The most popular simulation approaches for large-scale scenarios today are aggregated models. Unfortunately, these models lack temporal and spatial resolution. But microsimulations are interesting for traffic flow simulation, as they can accurately simulate features requiring both high temporal and high spatial resolution, including traffic jams and peak periods. However, most microscopic approaches involve high computational costs and expensive large computers to run them within a reasonable time. This work presents possibilities for reducing these costs by using a queue-based model and an event-driven approach jointly. The approach makes it possible to run large-scale scenarios with more than 1 million simulated person-days on networks with 10,000 links in less than 10 min on single CPU desktop computers present in most offices today.
Published in: Transportation research record
Volume: 2003
Pages: 35 - 40
ISSN: 0361-1981
Publication date / Date received: 2007-01-01
Publication status: Washington, D.C.
Publication status: Published
Subjects: Architektur, Gebaute Umwelt und Umweltgestaltung allgemein|Architecture, Built Environment and Environmental Design, General
Language: English
Review status: Peer reviewed
DBID source: PP-38140
DOI: 10.3141/2003-05
Nebis system number: 000024408
, Charypar, David, Axhausen, Kay W., Nagel, Kai, 2007 >>
Author(s): Charypar, David, Axhausen, Kay W., Nagel, Kai
Title: An Event-Driven Parallel Queue-Based Microsimulation for Large Scale Traffic Scenarios
Abstract: Traffic flow microsimulations are interesting for transport planning problems due to their high temporal and spatial resolution. Unfortunately, most of them involve high computational costs making them impractical for running large scale scenarios. This paper will present a parallel microsimulation software that uses queue-based link dynamics together with event processing instead of time-steps. By introducing appropriate load balancing and by minimizing interfaces between processors to reduce communication needs as far as possible, our simulator requires only 87 seconds on 64 processors to simulate a 24 hours test scenario with 7 million simulated person days on a network with 28k links.
Book title: 11th World Conference on Transport Research : June 24 - 28, 2007, University of California, Berkeley, CA = Conférence Mondiale sur la Recherche dans les Transports
Publication date / Date received: 2007-01-01
Publication status: Lyon
Publication status: Published
Event name: 11th World Conference of Transport Research
Event date: June 24-28, 2007
Place: Berkeley, CA, USA
Language: English
Review status: Peer reviewed
DBID source: FORM-1316265186, PP-33246
, Charypar, David, 2007 >>
Author(s): Charypar, David
Title: Mikroskopische Simulation des Schweizer Verkehrsaufkommens
Publication date / Date received: 2007-01-01
Publication status: Published
Event name: Treffpunkt Science City
Event date: November 11, 2007
Place: Zürich, Switzerland
Language: German
Review status: Unknown
DBID source: FORM-1306417203
, Charypar, David, Nagel, Kai, Axhausen, Kay W., 2006 >>
Author(s): Charypar, David, Nagel, Kai, Axhausen, Kay W.
Title: An event-driven queue-based microsimulation of traffic flow
Abstract: Simulating traffic flow is an important problem in transport planning. The most popular simulation approaches for large-scale scenarios today are aggregated models. Unfortunately, these models lack temporal and spatial resolution. But microsimulations are interesting for traffic flow simulation, as they can accurately simulate features requiring both high temporal and high spatial resolution, including traffic jams and peak periods. However, most microscopic approaches involve high computational costs and expensive large computers to run them within a reasonable time. This work presents possibilities for reducing these costs by using a queue-based model and an event-driven approach jointly. The approach makes it possible to run large-scale scenarios with more than 1 million simulated person-days on networks with 10,000 links in less than 10 min on single CPU desktop computers present in most offices today.
Published in: Transportation research record
Volume: 2003 / 2007
Pages: 35 - 40
ISSN: 0361-1981
Publication date / Date received: 2006-01-01
Publication status: Washington, DC
Publication status: Published
Event name: 86th Annual Meeting of the Transportation Research Board
Event date: January 21-25, 2007
Place: Washington, DC
Language: English
Review status: Peer reviewed
DBID source: PP-30960
DOI: 10.3141/2003-05
Nebis system number: 000024408
, Charypar, David, Axhausen, Kay W., Nagel, Kai, 2006 >>
Author(s): Charypar, David, Axhausen, Kay W., Nagel, Kai
Title: Implementing activity-based models
Subtitle: Accelerating the replanning process of agents using an evolution strategy
Abstract: We present recent advances in accelerating our agent-based simulation of travel demand by improving various modules of the simulation system. First, the optimization algorithm used in the replanning module is replaced by an evolution strategy that has shown to perform well on a variety of optimization problems including noisy and distorted search spaces. The replanning module is then extended by an accurate way of estimating time-dependent travel times. This makes it possible for the replanning module to produce better plans more quickly. Second, the percentage of computational agents that replan their days is investigated and a percentage that decreases with the iteration number is found to improve the learning speed significantly. On top of these changes a new, fast event-driven microsimulation of traffic flow is incorporated into the model to make the execution of the overall system less time consuming.2
Published in: Arbeitsbericht Verkehrs- und Raumplanung
Volume: 387
Publication date / Date received: 2006-01-01
Publication status: Zürich
Publication status: Published
Subjects: Daily plan optimization, Agent-based travel behavior simulation, Evolution strategy
Event name: 11th International Conference on Travel Behaviour Research
Event date: August 16-20, 2006
Place: Kyoto, Japan
Language: English
Review status: Peer reviewed
Keyword: Daily plan optimization, Agent-based travel behavior simulation, Evolution strategy
DBID source: FORM-1316713238, PP-31064
DOI: 10.3929/ethz-a-005228611
Nebis system number: 005228611
, Charypar, David, Axhausen, Kay W., Nagel, Kai, 2006 >>
Author(s): Charypar, David, Axhausen, Kay W., Nagel, Kai
Title: Implementing activity-based models
Subtitle: Accelerating the replanning process of agents using an evolution strategy
Publication date / Date received: 2006-01-01
Publication status: Published
Event name: 6th Swiss Transport Research Conference
Event date: March 15–17, 2006
Place: Ascona, Switzerland
Language: English
Review status: Unknown
DBID source: FORM-1306426678
, Charypar, David, Nagel, Kai, 2005 >>
Author(s): Charypar, David, Nagel, Kai
Title: Q-learning for flexible learning of daily activity plans
Abstract: Q-learning is a method from artificial intelligence to solve the reinforcement learning problem (RLP), defined as follows. An agent is faced with a set of states, S. For each state s there is a set of actions, A(s), that the agent can take and that takes the agent (deterministically or stochastically) to another state. For each state the agent receives a (possibly stochastic) reward. The task is to select actions such that the reward is maximized. Activity generation is for demand generation in the context of transportation simulation. For each member of a synthetic population, a daily activity plan stating a sequence of activities (e.g., home-work-shop-home), including locations and times, needs to be found. Activities at different locations generate demand for transportation. Activity generation can be modeled as an RLP with the states given by the triple (type of activity, starting time of activity, time already spent at activity). The possible actions are either to stay at a given activity or to move to another activity. Rewards are given as "utility per time slice," which corresponds to a coarse version of marginal utility. Q-learning has the property that, by repeating similar experiences over and over again, the agent looks forward in time; that is, the agent can also go on paths through state space in which high rewards are given only at the end. This paper presents computational results with such an algorithm for daily activity planning.
Published in: Transportation research record
Volume: 1935
Pages: 163 - 169
Publication date / Date received: 2005-01-01
Publication status: Washington, D.C.
Publication status: Published
Subjects: Architektur, Gebaute Umwelt und Umweltgestaltung allgemein|Architecture, Built Environment and Environmental Design, General
Language: English
Review status: Peer reviewed
DBID source: FORM-1288276447, WOS-000237194200019
DOI: 10.3141/1935-19
Nebis system number: 000024408
, Charypar, David, Nagel, Kai, 2005 >>
Author(s): Charypar, David, Nagel, Kai
Title: Generating complete all-day activity plans with genetic algorithms
Abstract: Activity-based demand generation contructs complete all-day activity plans for each member of a population, and derives transportation demand from the fact that consecutive activities at different locations need to be connected by travel. Besides many other advantages, activity-based demand generation also fits well into the paradigm of multi-agent simulation, where each traveler is kept as an individual throughout the whole modeling process. In this paper, we present a new approach to the problem, which uses genetic algorithms (GA). Our GA keeps, for each member of the population, several instances of possible all-day activity plans in memory. Those plans are modified by mutation and crossover, while 'bad' instances are eventually discarded. Any GA needs a fitness function to evaluate the performance of each instance. For all-day activity plans, it makes sense to use a utility function to obtain such fitness. In consequence, a significant part of the paper is spent discussing such a utility function. In addition, the paper shows the performance of the algorithm to a few selected problems, including very busy and rather non-busy days.
Published in: Transportation
Volume: 32
Issue: 4
Pages: 369 - 397
ISSN: 0049-4488, 1572-9435
Publication date / Date received: 2005-01-01
Publication status: Heidelberg
Publication status: Published
Subjects: Verkehr und Transport|Traffic and Transportation, Activity generation, Genetic algorithms, Location choice, Multi-agent traffic simulation, Utility functions
Language: English
Review status: Peer reviewed
Keyword: Activity generation, Genetic algorithms, Location choice, Multi-agent traffic simulation, Utility functions
DBID source: WOS-000227904800004, PP-19559
DOI: 10.1007/s11116-004-8287-y
Nebis system number: 000056550

 

 

 

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