This paper is concerned with the train timetabling problem that minimizes the total train travel time subject to a set of operational and safety requirements on a single-track rail line. A generalized resource constrained project scheduling formulation is proposed to consider segment and station capacities as limited resources, and a branch-and-bound solution procedure is presented to obtain feasible schedules with guaranteed optimality. The proposed search algorithm eliminates train conflicts chronologically by adding precedence relation constraints between conflicting trains, while the resulting subproblems are solved by the longest path algorithm that determines earliest start times for each train at segments. In order to effectively reduce the search space, a Lagrangian relaxation based lower bound rule is used to dualize segment and station capacity constraints and decompose the original complex problem into single train scheduling problems. Another exact lower bound rule is also embedded into the branch-and-bound search procedure to estimate the least train delay for resolving each existing crossing conflict in a partial schedule. In addition, this paper applies a beam search heuristic method to provide tight initial upper bounds. Based on a real-world train timetable, comprehensive numerical experiments are conducted to illustrate the computational performance of lower bound rules and evaluate several constructive heuristic methods.

Single-Track Train Timetabling with Guaranteed Optimality: Branch-and-Bound Algorithms with Enhanced Lower Bounds

Purpose. The work is aimed to investigate the feasibility of transferring automatic control to low-density stations of the sections (according to the principle of supervisory control of trainline) to the operators at principal stations. Methodology. The article analyzes the work of heavy traffic sections of the Ukrainian Railways JSC. It was found out that the information workload of dispatchers who control the train movement at the sections of the main course, constantly exceeds the permissible level. The possibility of using the technology of supervisory control of train movement by the introduction of operational zones has been investigated. Findings. The authors found out that the capacity of receiving and departure tracks at the stations of the sections is extremely limited. The occupancy of run-around tracks by the out-of-work trains hinders any regulatory measures at the sections. Trains pass one after another without giving priority, that is, they pass through the section in the order in which they entered it. Due to the limited number of tracks at the pre-section intermediate station, freight trains are placed for run-around by the passenger ones at the distant approaches. This leads to a loss of service speed and reduces the level of utilization of the sections` working capacity. The introduction of operational zones will significantly reduce information flows and facilitate the work of the train dispatchers, create the necessary conditions for creative decision-making on the inter-sectional regulation, and will contribute to increase in the service speed of trains. Originality. The article developed a new technology to improve the management of train sections by dividing them into operational zones. In each zone, consisting of two or three run-arounds, the duty officer of the principal station, performing in this case the functions of the train dispatcher, can control the train movement. Practical value. It has been proposed to put trains from technical stations that idle due to uneven movement, especially the trains from the terminal stations (division points) of the locomotive circulation sections, to reserve routes of the pre-section intermediate stations. Laying the reserve tracks and their maintenance, taking into account the periodicity of use and reduced permissible speed, can be allowed according to less tight standards for the construction of the roadbed, ballast section, sleeper density, taking into account the use of switches and decommissioned tracks.

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Improvement of supervisory control of train movement by means of introduction of operational zones

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Дослідження інтенсивності руху спеціалізованих поїздопотоків в умовах ризиків

Purpose. Scientific research is aimed at gaining new knowledge about the structure of a typical regulatory and technological document (regulation) of access for private-owned train locomotives to public railway infrastructure. Methodology. To obtain relevant empirical data, the authors performed a review of previous studies on the topic of work using full-text and abstract databases. In accordance with the principles of system analysis and mathematical logic, structural-logical models of the order of interaction between the units of the operator (owner) of the public railway infrastructure and representatives of the owner of private locomotives have been developed. Findings. The authors proved: 1) the regulation of access of private train locomotives to public infrastructure is a certain procedure (technological process) for the interaction of the owner (operator) of private locomotives with the units of the owner of the infrastructure (dispatch or operational personnel, employees of commercial and carriage facilities); 2) the structure of the typical regulation includes the following blocks: the technological process, the procedure for processing transportation documents and charging fees, the procedure for operating private locomotives and preparing of locomotive’s foot-plate staff for the tour; the procedure and responsibility of the parties in case of emergency situations. Originality lies in improving the models for the organization of railway carriage traffic volumes and the movement of trains on public railways, which, unlike the existing ones, imply the decentralized management of the locomotive fleet. Practical value lies in the possibility of direct practical application of the proposed models for the creation of standard recommendations for drawing up rules for the access of private locomotives to the hauling operations on the public railway infrastructure and their practical testing in the corresponding pilot project on one of the railway lines in Ukraine. According to the research results: 1) the necessary structure of the access regulation of private train locomotives to the public railway infrastructure was determined; 2) a logical order for interpreting the interaction between the relevant units of the owner (operator) of the public railway infrastructure and locomotive traction operators (owners of private locomotives) has been created.

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Концепція регламенту доступу приватних поїзних локомотивів до залізничної інфраструктури загального користування

Purpose. The tasks of selecting the optimal modes of mutual operation of the public and non-public tracks are particularly relevant in the context of increasing the share of private cars. Therefore, the aim of this paper is to develop an approach to the justification of the choice of the interaction mode between mainline and industrial railway transport from the position of cars distribution sent to parking between public and non-public railway tracks. Me-thodology. To achieve this purpose, authors used the methods of scientific analysis and synthesis, graph theory, as well as experimental and statistical methods of modeling. Findings. Dependence of the required capacity of railway tracks was obtained. It takes into account the share of private cars in the general park arriving at places of non-public use. We proposed a scheme for choosing the place of location of cars to justify the choice of the mode of interaction between the main and industrial railway transport, taking into account the available track equipment and the expediency of its further development. Originality. The task in this formulation has not been solved to date, which determines the relevance and originality of research in this direction. The resulting formula for determining the required capacity of railway tracks takes into account the influence of the random nature of servicing of private conveyances at places of non-public use, as well as the share of carriages of consignors, consignees in the general park. We proposed the method for choosing the location of private rolling stock, used to justify the choice of the mode of interaction between the main and industrial railway transport, taking into account the available track equipment and the expediency of its further development. A distinctive feature of the presented method is the consideration of the interests of the cargo owner, as a party most interested in the effective mutual work of public and non-public railway tracks. Practical value. Based on the results of the study recommendations can be received on the choice of the mode of interaction between the main and industrial railway transport in the part of the cars distribution sent to parking between public and non-public railway tracks. This will reduce the costs of cargo owners by minimizing economic and time losses and, as a result, make railroad services more attractive to customers, which will lead to an increase in its competitiveness in the transport services market.

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Rolling stock distribution for parking between public and non-public railway tracks

Purpose. In this paper it is necessary to analyze the types of competition in the transport market in order to find ways to improve the competitiveness of railway transport and to determine the ensuring equal conditions for all market participants by eliminating discrimination in competition. Methodology. Analysis of recent research and publications on the subject was held by the authors. The question of the development of competition, increased competitiveness in railway transport was investigated. Attention is drawn to the fact that due to the decline in traffic volumes on all modes of transport competition may significantly change the usual sphere the effective use of different modes of transport. Every mode of transport occupies a particular segment of the transport market, taking into account its technical and economic features, weakly competing, and in some cases do not compete with each other (except the road transport). However, it is entirely possible competition inside these segments. Findings. The problems of management of competitiveness, including the transport market, which required extensive analysis and serious scientific study, were identified. Originality. As a result of this work the features of transport and production of transport in modern conditions were structured. The dependences of passenger turnover and freight turnover by mode of transport over the past decade were shown. The question of additional profits by providing the cargo owners a range of service was examined. The optimal combination of cost and quality of such services at each transportation company promotes increasing its competitive status. Practical value. Competition between enterprises of the industry put the aim of improving the competitiveness of not only railway subsystems directly involved in technology movement of cargoes and the movement of passengers, but also the organization of infrastructure in the first place – subsystems to expand services and improve service for passengers and cargo owners. Ensuring of equal conditions for all market participants is achieved through a ban of three key anti-competitive actions: the adoption of agreements restricting competition; abuse of a dominant (monopolistic) position and mergers, which result in a dominant market position to restrict competition.

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P. V. Bech

Papers

Improvement of supervisory control of train movement by means of introduction of operational zones

Ways to increase competitiveness of railway transport in modern conditions