Railroad Scheduling Research Articles

Modified Kleene Star Algorithm Using Max-Plus Algebra and Its Application in the Railroad Scheduling Graphical User Interface

In max-plus algebra, some algorithms for determining the eigenvector of irreducible matrices are the power algorithm and the Kleene star algorithm. In this research, a modified Kleene star algorithm will be discussed to compensate for the disadvantages of the Kleene star algorithm. The Kleene star algorithm’s time complexity is O(n(n!)), and the new Kleene star algorithm’s time complexity is O(n4), while the power algorithm’s time complexity cannot be calculated. This research also applies max-plus algebra in a railroad network scheduling problem, constructing a graphical user interface to perform schedule calculations quickly and easily.

A Rescheduling Algorithm of Train-Group for Railway Emergencies and its Parallelization

In order to reduce the delays of train groups when suffering from railroad emergencies, we propose a rescheduling algorithm of train groups to reschedule trains, instead of previous just waiting. A heuristic algorithm is designed to search the proper path for the trains involved in the railroad emergencies. An evaluation criterion based on the extent of the disturbance towards the original timetable and limited time is designed to select the optimal path for each train. And a conflicts resolution strategy is designed to deal with the path and time conflicts among trains when rescheduling. In the end, due to the real-time needs of the railroad scheduling, we implement the parallel processing for the train-group rescheduling referring to the allocation of loads. Experimental results show that the rescheduling algorithm is efficient to reduce the delays of train groups and the parallel processing meets the real-time response of the train-group rescheduling well.

Visual Exploration and Analysis of Historic Hotel Visits

Understanding the spatial and temporal characteristics of individual and group behavior in social networks is a critical component of visual tools for intelligence analysis, emergency management, consumer analysis, and human geography. Identification and analysis of patterns of recurring events is an essential feature of such tools. In this paper, we describe an interactive visual tool for exploring the visitation patterns of guests at two hotels in central Pennsylvania from 1894 to 1900. The centerpiece of the tool is a wrapping spreadsheet technique, called reruns, that reveals regular and irregular periodic patterns of events in multiple overlapping artificial and natural calendars. Implemented as a coordinated multiple view visualization in Improvise, the tool is in ongoing development through an iterative process of data collection, transcription, hypothesis, design, discovery, analysis, and evaluation in close collaboration with historical geographers. Numerous discoveries have driven additional data collection from archival newspaper and census sources, as well as plans to enhance analysis of spatial patterns using historic weather records and railroad schedules. Distributed online evaluations of usability and usefulness have resulted in feature and design recommendations that are being incorporated into the tool.

Optimizing railway timetables with OpenTimeTable

OpenTimeTable is a computer program that is designed to help railway timetable planners evaluate actual schedule adherence data. The program analyzes the differences between actual and scheduled timetable data and presents this information in variety of statistical and graphical formats. Railroad planners use this information to improve timetables, which ultimately leads to a more attractive service and more efficient infrastructure utilization. Schedule planners use OpenTimeTable to download actual timetable data for a specified corridor from railroad company databases. Next, they produce graphical timetables, delay distributions, capacity utilization graphs, and a variety of statistical data from the downloaded information. Generally planners perform these analyses in an interactive manner to better understand reasons for systematic schedule delays and develop measures need to address them. OpenTimeTable was developed by the Swiss Federal Institute of Technology's Institute for Transportation Planning and Systems in cooperation with the Swiss Federal Railways. The paper describes OpenTimeTable and outlines the program can be used to improve railroad schedules.

Solving Real-Life Locomotive-Scheduling Problems

In the locomotive-scheduling problem (or the locomotive-assignment problem), we must assign a consist (a set of locomotives) to each train in a preplanned train schedule so as to provide each train with sufficient locomotive power to pull the train from its origin to its destination. Locomotive-scheduling problems are among the most important problems in railroad scheduling. In this paper, we report the results of a study on the locomotive-scheduling problem as it is faced by CSX Transportation, a major U.S. railroad company. We consider the planning version of the locomotive-scheduling model (LSM) in which multiple types of locomotives exist, and we need to decide which set of locomotives should be assigned to each train. We present an integrated model that determines: the set of active and deadheaded locomotives for each train; the light-traveling locomotives from power sources to power sinks; and train-to-train connections (for which we specify which inbound trains and outbound trains can directly connect). An important feature of our model is that we explicitly consider consist bustings and consistency. A consist is said to be busted when a set of locomotives coming on an inbound train is broken into subsets to be reassigned to two or more outbound trains. A solution is consistent over a week if a train receives the same locomotive assignment each day that it runs. We will provide a mixed-integer programming (MIP) formulation of the locomotive-assignment problem. However, an MIP of this size cannot be solved to optimality or near optimality in acceptable running times using commercially available software. Using problem decomposition, integer programming, and very large-scale neighborhood search, we have developed a solution technique to solve this problem within 30 minutes of computation time on a Pentium III computer. Our solution obtained a potential savings of over 400 locomotives over the solution obtained by the in-house software developed by CSX.

Solving Real-Life Locomotive Scheduling Problems

The locomotive scheduling problem (or the locomotive assignment problem) is to assign a consist (a set of locomotives) to each train in a pre-planned train schedule so as to provide them sufficient power to pull them from their origins to their destinations. Locomotive scheduling problems are among the most important problems in railroad scheduling. In this paper, we report the results of a study of the locomotive scheduling problem faced by CSX Transportation, a major US railroad company. We consider the planning version of the locomotive scheduling model (LSM), where there are multiple types of locomotives and we need to decide the set of locomotives to be assigned to each train. We present an integrated model that determines the set of active and deadheaded locomotives for each train, light traveling locomotives from power sources to power sinks, and train-to-train connections (specifying which inbound train and outbound trains can directly connect). An important feature of our model is that we explicitly consider consist-bustings and consistency. A consist is said to be busted when the set of locomotives coming on an inbound train is broken into subsets to be reassigned to two or more outbound trains. A solution is said to be consistent over a week with respect to a train, if the train gets the same locomotive assignment each day it runs. We give a mixed integer programming (MIP) formulation of the problem that contains about 197 thousand integer variables and 67 thousand constraints. An MIP of this size cannot be solved to optimality or near-optimality in acceptable running times using commercially available software. Using problem decomposition, integer programming, and very large-scale neighborhood search, we developed a solution technique to solve this problem within 30 minutes of computation time on a Pentium III computer. When we compared our solution with the solution obtained by the software in-house developed by CSX, we obtained a savings of over 400 locomotives, which translates into savings of over one hundred million dollars annually.

A Model for the Optimal Programming of Railway Freight Train Movements

The area of railroad scheduling and associated problems offers a potentially fruitful field for research in management science. The mass of data; the need for considering numerous aspects of the problem simultaneously; and the variety of restrictions (arising from the technology, labor agreements and government regulation) make the control of day to day operations a management problem of great complexity. The problems at this level are further compounded by the need for developing, at the same time, methods for planning and evaluating major changes in facilities. Such methods, if they are to be effective, must be capable of tracing out the implications of these changes on the day to day operation and appraising the results in the light of the long-run objectives of the railroad. This paper is an account of an attempt to apply certain techniques of management science to some of these scheduling problems as they were found to exist on a large terminal switching railroad.

Union pacific's new steam-electric locomotive

The need for faster railroad schedules has necessitated the development of new motive-power units capable of sustained high-speed operation. Newest entrant in that realm is the steam-electric locomotive recently placed in operation by the Union Pacific Railroad.

ASSOCIATION NEWS

<h3>NOTES ON NEW ORLEANS.</h3> Final Announcements Concerning the Session Next Week. The Bureau of Information of the New Orleans session, which will be located on the ground floor of the Artillery Hall, entrance on St. Charles street, announces the following: Members of the committee will meet all incoming trains May 4 and 5. Placards will be in evidence in each station indicating where these gentlemen will be found. The bureau will have every facility for supplying all kinds of information; this means male and female clerks, index lists of all visiting physicians and their ladies, railroad schedules, excursion information, telegraph, telephone, stenographer and typewriter, messenger services, guide books, newspapers, cigars, etc. The committee has completed all plans for the meeting and urge all members not located to inquire at the Bureau of Information for rooms. Members of the profession are advised that badges will be furnished only to those who