Inst. Land- und Seeverkehr (ILS)

251 Items

Recent Submissions
The physics of traffic and regional development

Helbing, Dirk ; Nagel, Kai (2004)

This contribution summarizes and explains various principles from physics which are used for the simulation of traffic flows in large street networks, the modelling of destination, transport mode, and route choice, or the simulation of urban growth and regional development. The methods stem from many-particle physics, from kinetic gas theory, or fluid dynamics. They involve energy and entropy c...

Incorporating within link dynamics in an agent-based computationally faster and scalable queue model

Agarwal, Amit ; Lämmel, Gregor ; Nagel, Kai (2017)

The growing pace of urbanization increases the need of simulation models to handle large-scale scenarios in reasonable time. The present study proposes a fast spatial queue model, which is anchored to an agent-based travel demand simulation framework. The existing queue model is extended to produce more realistic flow dynamics by introducing backward travelling holes to mixed traffic conditions...

Mind the price gap: How optimal emission pricing relates to the EU CO2 reduction targets

Kickhöfer, Benjamin ; Agarwal, Amit ; Nagel, Kai (2018)

From the transport economic literature, it is known that optimal pricing of (environmental) externalities improves the urban system. In contrast to theory-based optimal pricing strategies, real-world policy setting often follows so-called “backcasting” approaches where certain targets are set, and policy measures are implemented in order to reach those targets. An example for the latter approac...

Adaptive traffic signal control for real-world scenarios in agent-based transport simulations

Thunig, Theresa ; Kühnel, Nico ; Nagel, Kai (2019)

This study provides an open-source implementation of a decentralized, adaptive signal control algorithm in the agent-based transport simulation MATSim, which is applicable for large-scale real-world scenarios. The implementation is based on the algorithm proposed by Lämmer and Helbing (2008), which had promising results, but was not applicable to real-world scenarios in its published form. The ...

Effect of suspension system in the lateral stability of railway freight trucks

Molatefi, Habibollah ; Hecht, Markus ; Kadivar, M. H. (2007)

In the current research an empty freight wagon with BA652 and an old BA661 bogies have been modelled. Non-linear creep forces with spin moment between wheel and rail have been used and also all impacts and friction forces have been modelled. The characteristics of primary suspension systems for BA652 and an old BA661 have been evaluated by means of test. Non-linear equations of motions and kine...

Critical speed and limit cycles in the empty Y25-freight wagon

Molatefi, Habibollah ; Hecht, Markus ; Kadivar, M. H. (2006)

In this research, an empty freight wagon with Y25 bogies have been modelled. Non-linear creep forces with spin moment between wheel and rail have been used, and also all impacts and friction forces have been modelled. Non-linear equations of motion and kinematical constraints have been solved in time domain, and limit cycles, saddle nodes, and critical speeds have been shown. Both primary and s...

Wear and energy-saving freight bogie designs with rubber primary springs: principles and experiences

Hecht, Markus (2009)

The traditional radial steering bogie with swing hanger links is known to be track-friendly but heavy, and expensive in investment and maintenance costs. Whereas the actual bogies with longitudinal stiff axle guidance such as Y25 cause severe wear on wheels and rails in curves, and also develop high running resistance in curves. Bogies with rubbers springs like double rubber ring spring (DRRS),...

European freight vehicle running gear: Today's position and future demands

Hecht, Markus (2001)

The running gear of most of the rail freight vehicles in operation today tends to be built to very old designs. The running gear for new freight rolling stock and, in particular, new types of bogie must have significantly improved performance if they are to satisfy the demands of all the stakeholders associated with the railways. Improved performance in this context means reduced inspection tim...

Bewertung verschiedener Alternativen zur Kraftstoff‭‭‭‭-‭Einsparung im privaten Pkw-Verkehr

Heinze, G. Wolfgang ; Kanzlerski, Dieter ; Wagner, Gerhard (1974)

Die Ölkrise 1973 führte auch in Deutschland zu politischen Auffanglösungen. Dazu gehörten vor allem vier aufeinanderfolgende autofreie Sonntage ab 25. November 1973 sowie allgemeine Geschwindigkeitsbegrenzungen für sechs Monate. Die Sonntags-fahrverbote stellten entferntere Tourismus- und Freizeitgebiete vor besondere Probleme und verstärkten die Suche nach. raumordnungspolitisch verträglichere...

Charakterisierung des Verdichterpumpens eines kleinen Abgasturboladers

Werner, Moritz (2018)

In der vorliegenden Arbeit werden die Verdichterinstabilitäten eines Abgasturboladers untersucht, welcher zur Aufladung eines kleinen Ottomotors entwickelt wurde. Diese Instabilitäten, insbesondere das Verdichterpumpen, sind am Fahrzeugmotor auszuschließen, um einen sicheren und stabilen Betrieb zu gewährleisten und Schäden zu vermeiden. So ist die Kenntnis der Lage der Pumpgrenze von besondere...

Analysis of flow phenomena inside moonpools in operational and transit conditions

Löhrmann, Jan (2018)

The flow phenomena inside moonpools under different conditions have been analysed within this thesis. The water oscillation behaviour was investigated for moonpool geometries of different size and length to breadth ratio for the ship in transit condition at different Froude numbers, as well as for operational condition with the ship at rest. Calm water, as well as regular waves of different wav...

CO2-Reduktion für schwere Güterkraftfahrzeuge im Fernverkehr

Dunger, Torsten (2018)

Aus klimapolitischer Sicht müssen die CO2-Emissionen des schweren Langstreckengüterkraftverkehrs deutlich reduziert werden. Maßnahmen aus dem Pkw-Bereich oder dem Verteilerverkehr lassen sich aufgrund abweichender Randbedingungen nur schlecht übertragen. In dieser Arbeit werden die Randbedingungen spezifiziert und darauf basierend systematisch Konzepte für einen CO2-freien Fernverkehrsantrieb e...

Policy Evaluation in Multiagent Transport Simulations

Grether, Dominik ; Kickhöfer, Benjamin ; Nagel, Kai (2010)

In democratically organized societies, the implementation of measures with regressive effects on welfare distribution tends to be complicated because of low public acceptance. The microscopic multiagent simulation approach presented in this paper can help to design better solutions in such situations. Income can be included in utility calculations for a better understanding of problems linked t...

Adding Mode Choice to Multiagent Transport Simulation

Rieser, Marcel ; Grether, Dominik ; Nagel, Kai (2009)

It had been shown previously that so-called agent-based traffic micro-simulations could be used for dynamic traffic assignment, that is, iterative route adjustment, until either a Nash equilibrium or some steady state distribution between alternatives had been found. It was also shown that the same approach could be extended to (departure) time adjustment; that is, time adjustment and route adj...

Agent-Oriented Coupling of Activity-Based Demand Generation with Multiagent Traffic Simulation

Rieser, Marcel ; Nagel, Kai ; Beuck, Ulrike ; Balmer, Michael ; Rümenapp, Jens (2007)

The typical method to couple activity-based demand generation (ABDG) and dynamic traffic assignment (DTA) is time-dependent origin-destination (O-D) matrices. With that coupling method, the individual traveler's information gets lost. Delays at one trip do not affect later trips. However, it is possible to retain the full agent information from the ABDG by writing out all agents' plans, instead...

Agent-Based Demand-Modeling Framework for Large-Scale Microsimulations

Balmer, Michael ; Axhausen, Kay W. ; Nagel, Kai (2006)

Microsimulation is becoming increasingly important in traffic demand modeling. The major advantage over traditional four-step models is the ability to simulate each traveler individually. Decision-making processes can be included for each individual. Traffic demand is the result of the different decisions made by individuals; these decisions lead to plans that the individuals then try to optimi...

Modeling Location Choice of Secondary Activities with a Social Network of Cooperative Agents

Marchal, Fabrice ; Nagel, Kai (2005)

Activity-based models in transportation science focus on the description of human trips and activities. Modeling the spatial decision for so-called secondary activities is addressed in this paper. Given both home and work locations, where do individuals perform activities such as shopping and leisure? Simulation of these decisions using random utility models requires a full enumeration of possi...

Robustness of Efficient Passenger Boarding Strategies for Airplanes

Ferrari, Pieric ; Nagel, Kai (2005)

Common wisdom is that airplanes make money only when they are in the air. Therefore, turnaround time (turn time) on the ground should be reduced as much as possible. An important contribution to the turn time is airplane boarding time. Many different schemes are in use, from random seat selection to sophisticated boarding groups. A simulation model is described to evaluate different boarding st...

Integrating CEMDAP and MATSIM to Increase the Transferability of Transport Demand Models

Ziemke, Dominik ; Nagel, Kai ; Bhat, Chandra (2015)

An activity-based approach to transport demand modeling is considered the most behaviorally sound procedure to assess the effects of transport policies. This paper investigates whether it is possible to transfer an estimated model for activity generation from elsewhere (the estimation context) and use local area (application context) traffic counts to develop a local area activity-based transpo...

Activity-Based Computation of Marginal Noise Exposure Costs

Kaddoura, Ihab ; Nagel, Kai (2016)

In this paper, an innovative simulation-based approach is presented to calculate optimal dynamic, road- and vehicle-specific tolls on the basis of marginal traffic noise exposures. The proposed approach combines the advantages of an activity-based simulation with the economically optimal way of price setting. Temporal and spatial differences of traffic noise levels and population densities are ...