Multi-carrier track capacity allocation in forward and spot markets of freight transport

This dissertation addresses multi-carrier, multi-line train scheduling problems for forward and spot markets. Schedules resulting from solution of these train scheduling problems enable carriers to make customer commitments for serving forward contracts and to transport one-off-loads arising on spot markets. A train slot selection model based on multicommodity network flow concepts is developed for determining timetables for use in forward markets and a column generation methodology is proposed for its solution. The model considers needs of both shippers and carriers. The solution approach is embedded in a simulation-based iterative framework, where demand elasticity is explicitly treated. A combinatorial auction-based track capacity allocation framework is introduced to allocate residual track capacity among competing carriers seeking to run additional trains on an as-needed basis. Bid set construction techniques are proposed that allow carriers to express their preferences for track usage. A winner determination problem is formulated, solution of which provides the optimal allocation of track capacity among carriers. The potential benefits of collaborative operation among carriers in both markets were recognized. Collaborative decision-making (CDM) strategies are designed for scheduling trains to serve forward markets. Performances of these strategies are assessed in a carrier collaboration simulation-assignment framework. A train space leasing technique and a CA-based train slot creation approach are proposed to accommodate one-off-loads on previously scheduled and newly formed trains, respectively. Required techniques for bid set construction are developed. A WDP is formulated that seeks the optimal allocation of track access rights to bidders for the given bid sets. Implementation of the resulting train schedules will aid in creating efficient and cost-effective rail transport, resulting in a competitive and green alternative to truck transportation. Additionally, collaboration among competing carriers can lead to the formation of profitable trains that might otherwise have been underutilized and an ability of each carrier to serve a greater share of the freight market. The methodologies were specifically intended for solving large, real-world train scheduling problems

Railway Revenue Management: Overview and Models (Operations Research)

The railway industry offers similar revenue management opportunities to those found in the airline industry. The railway industry caters for the delivery and management of cargo as well as the transport of passengers. Unlike the airline industry, the railway industry has seen relatively little attention to revenue management problems. We provide an overview of the published literature for both passenger and freight rail revenue management. We include a summary of the some the available models and include some possible extensions. From the existing literature and talks with industry, it is clear that that there is room to exploit revenue management techniques in the railway industry, an industry that has revenues of $60 billion in the US and promises huge growth in Europe in the forthcoming years.operations research, marketing, network economics, business economics, railway, revenue management, pricing, passenger, freight, models

Sea Container Terminals

Due to a rapid growth in world trade and a huge increase in containerized goods, sea container terminals play a vital role in globe-spanning supply chains. Container terminals should be able to handle large ships, with large call sizes within the shortest time possible, and at competitive rates. In response, terminal operators, shipping liners, and port authorities are investing in new technologies to improve container handling infrastructure and operational efficiency. Container terminals face challenging research problems which have received much attention from the academic community. The focus of this paper is to highlight the recent developments in the container terminals, which can be categorized into three areas: (1) innovative container terminal technologies, (2) new OR directions and models for existing research areas, and (3) emerging areas in container terminal research. By choosing this focus, we complement existing reviews on container terminal operations

Dynamic bulk freight train scheduling in an uncongested rail network

Dissertation for the degree of Master of Science University of the Witwatersrand Johannesburg. April 2013Many academic works in the train scheduling environment concentrate on optimizing movements of resources through the physical network. To opti- mize bulk freight lines, algorithms must provide a feasible schedule given the available resources, basic operational constraints and varying demand while ensuring resource allocations that minimise total cost. To be usable the al- gorithm must run within reasonable time limits. This dissertation focuses on the bulk freight train scheduling problem of full loads without track conges- tion but extends to cover operational constraints as well as exible resource allocation and hubs. A problem outline is given wherein the constraints and decision variables are well de ned followed by a review of current literature. An exact formation of the problem is given with benchmarking on small data sets. A genetic algorithm is used to solve for schedules on larger problem data sets. The algorithm was successfully implemented on the 60Mt Coal Line in South Africa which provided notable improvements in e ciencies. Discussion and results are provided

Port Rail Shunting Optimization Problems

openThe work focuses on a particular section of the intermodal chain of freight transportation, which is the link between rail and sea transportation modes and happens in the maritime port area. Among this field, the study deals with the management of rail operations, called here rail shunting operations, that have to be performed in the port area. Two optimization problems arises in this context. The first concerns the scheduling of the rail shunting operations, here called Port Rail Shunting Scheduling Problem (PRSSP). The second deals with the re-scheduling of the same operations in case of unpredictable events, here called Port Rail Shunting Re-Scheduling Problem (PRSRP). After a literature overview on the concerning studies, we concentrate on an innovative way to use the well known space-time networks as solution approach structure for both the above mentioned problems. The innovative structure has been called operation-time-space network and is deeply analyzed in a dedicated chapter. A network flow model based on an operation-time-space network for solving PRSSP has been developed. It has been tested using random generated instances providing good results. The same model has been extended in order to solve PRSRP and it has been tested giving good results as well. Finally, the models have been used to solve the real case of a port area located in Italy in order to test the applicability of the developed models to a real context. The tests have been executed using real data and provided good results confirming the possibility to apply the proposed approach in similar real problems.openXXXIII CICLO - LOGISTICA E TRASPORTIAsta, Veronic

Modeling Uncertainty in Rail Freight Operations: Implications for Service Reliability

This thesis presents an operational simulation tool to evaluate different rail operational policies aimed at increasing service reliability in large-scale multi-carrier rail networks. Operational policies that improve shipment connection reliability at shunting yards, such as priority-based classification, train holding and train cancellation policies can be evaluated using the tool. To support operational decisions needed to implement priority-based classification, an optimization based framework is proposed. Operational policies to improve train schedule reliability, such as including slack time in timetables to handle minor delays, and rescheduling strategies to manage large delays can also be evaluated using the tool. For minor delays, analytical method for deterministic analysis of propagation of delays in train traffic networks is proposed and demonstrated on the Washington DC Metrorail Network. Rescheduling strategies required to manage large delays in multi-carrier rail networks are also discussed herein. A dynamic slot request mechanism is proposed, wherein each carrier requests slots for N blocks ahead, to model rescheduling requests of multiple carriers competing for the slots. The proposed simulation tool is applied on a European rail freight network, the REORIENT network, to evaluate the effect of variability in border crossing times, slack time in timetable design, different rescheduling policies and slot request size (N) on service reliability and average delay to the trains in the system

Progress in Material Handling Research: 2012

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