A combined simulation approach for the effective integration of operational and strategic levels for intermodal transport modelling (original) (raw)
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2000
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Proceedings of the 2009 Winter Simulation Conference (WSC), 2009
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DEVELOPMENT OF STRATEGIC INFRASTRUCTURE AND TRAIN OPERATIONS MODELLING
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A simulation tool for combined rail/road transport in intermodal terminals
Mathematics and Computers in …, 2002
A simulation model of the flow of Intermodal Terminal Units (ITUs) among and within inland intermodal terminals is presented. The intermodal terminals are inter-connected by rail corridors. Each terminal serves a user catchment area via a road network. The terminal is modelled as a set of platforms, which are served by a number of gantry cranes and front lifters. The user of the simulation model defines the structure of the terminal and the train and truck arrival scenarios. The train arrivals are defined in a train timetable, while the patterns of truck arrivals for ITU delivery and pick-up can be either statistically modelled or given as a deterministic input. The simulator can be used to simulate both a single terminal and a rail network, that is, two or more interconnected terminals. During the simulation, various statistics are gathered to assess the performance of the terminal equipment, the ITU residence time, and the terminal throughput. The simulation software has been implemented as a discrete-event simulation model, using MODSIM III as development tool. The simulator tool has been developed as part of the PLATFORM project, funded by the Directorate General VII of the European Community.
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The availability of rail infrastructure resources is a major driver of rail operations performance. To evaluate the impact of infrastructure provision, network simulation models can be used to accurately represent train traffic behavior in a wide range of scenarios. However, performing this task can result in a problem of high combinatorial nature as the number of factors and their associated levels increase. This requires more sophisticated techniques such as experimental design formulations or optimization modeling in order to yield satisfactory results. Yet the research in network simulation models for rail systems has hitherto been limited to simple what-if analysis, made up from few factors that cannot represent the whole spectrum of interventions. This is especially critical in closed-loop rail systems where trains are subject to various interferences. Local improvements can be misleading as the queues are merely transferred within the network. Considering this, we propo...
Transportation Research Record: Journal of the Transportation Research Board, 2008
A dynamic intermodal multiproduct freight network simulationassignment model is presented with application to a large-scale intermodal rail network. Methodology pertaining to the simulation-assignment framework and representation and implementation considerations in dealing with large networks are discussed. The model is applied to a pan-European rail network spanning 11 countries from Scandinavia to Greece. Shipper decisions are disaggregated to an individual shipment level using a dynamic microassignment methodology in which a joint mode, path, service, and carrier choice is made. A mode choice function for this joint choice is calibrated, and issues relating to heterogeneity of freight characteristics are discussed. The model is validated by analyzing convergence patterns and measures of performance, namely, mode splits, compared with other studies. Two examples demonstrate the role of the model as a policy and decision support tool. The impact of expedited operations at international borders and infrastructure improvements on rail services is quantified.
A Simulation Modeling Methodology for Analyzing Large Complex Rail Networks
SIMULATION, 1995
As the congestion in the nation's freeways increases, the reliance on rail freight shipments is increasing. For this reason, models are needed to analyze the increased traffic burden on the rail networks. Compound delays and ripple effects from conflicts at complex junctions, terminals, and railroad-railroad crossings at grade and other factors in some rail networks make it difficult to develop analytical models to study delays and capacity. Therefore, a simulation modeling methodology for analyzing complex rail networks is proposed. The methodology considers both double-track and single-track lines and is insensitive to the size of the rail network. The proposed simulation modeling methodology is then used to analyze train movement from Downtown Los Angeles to the San Pedro Bay Ports.
Modelling a rail/road intermodal transportation system
Transportation Research Part E: Logistics and Transportation Review, 2004
This paper deals with the problem of optimally locating rail/road terminals for freight transport. A linear 0-1 program is formulated and solved by a heuristic approach. The model is applied to the rail/road transportation system in the Iberian Peninsula. Five planning scenarios are considered. It is shown that modal shares are very sensitive to the cost of rail and to that of track gauge changes at the Spanish border. Conversely, the location of the terminals has little or no impact on the market shares of the combined traffic, but location changes in the Peninsula generate consequences on the entire European transportation system.
A simulation-based approach for estimating railway capacity
International Journal of Transport Development and Integration 3(3), pp. 232-244, 2019
The paper proposes a simulation-based approach for supporting a threshold analysis aimed at identifying the maximum number of trains to be operated on a line, given the related infrastructural and operational constraints. The method addresses an intermediate case between the theoretical and practical capacity conditions (i.e. simulated capacity). Moreover, the evaluated capacity represents an upper-bound value and, therefore, it is independent of the involved demand flows which, hence, have been neglected in the provided discussion. In particular, against an initial effort for building the rail micro-simulation model, which requires the modelling of infrastructure layout, signalling system, rolling stock and planned timetable, the presented methodology allows infrastructure managers to properly direct the decision-making process by providing information on the effects of any intervention, in advance of its effective implementation. In order to show the feasibility and usefulness of the proposed approach, it has been applied in the case of a real rail network context in the south of Italy. Keywords: Railway systems, rail simulation models, railway capacity estimation, threshold analysis, timetabling design process.
PLOS ONE, 2022
Inland terminals, or dry ports, have played an important role in multimodal transportation networks as transportation hubs that provide connections between seaports and hinterland economies. While important, evaluating the operational performance of a dry port is especially challenging since it depends not only on internal factors, such as the variety and number of container handling equipment (CHE) deployed, but also on other external factors, including changes in transportation policies and container demands experienced by a dry port. To properly evaluate the holistic performance of a dry port while considering all the aforementioned factors, a discrete event simulation (DES) framework is herein developed and applied to the Ladkrabang Inland Container Depot (LICD)—one of the largest dry ports in Southeast Asia—under various operational settings. Despite complicated internal operations, the devised DES framework has shown itself useful in the analyses of LICD, due largely to its fl...