2013 Session: 553

• Railroad Lines and Cargo Transportation in Colombia
  Abstract: This article presents an overview of the evolution of the Colombian railroads system from a technical and operational point of view as well as the current potential which represents the use of trains to transport coal in the country. It also includes an administrative renovation that the Colombian government has undertaken to encourage the use of this mode, as well as projects the government wants to encourage with private sector support.
  Authors: Mora, Maria del Pilar
  Authors: Mora, Maria del Pilar
  Year: 2013
  Document Type: Paper
  Subject: Railroads; Rail
  Session: 553
  Paper Number: 13-0301
• Automated Generation of Test Cases and Sequences Based on Path Optimization Algorithm
  Abstract: Test is one of the key methodologies to guarantee the functionality correctness and safety of the railway signal system used in the operation line. The present test generation methods for the railway signal system in China are manual, which take too much time and are inefficient, so the automated test approach plays a more and more important role in the testing domain. This paper proposes an automated approach to generate a full set of the test cases and sequences. The all paths covered optimal algorithm (APCO) and the sequence priority algorithm (SPS) for automatically generating test cases and test sequences based on the CPN model are presented. Taking the scenario of Radio Blocking Center (RBC) handover as an example, the presented method is employed to generate the test cases and test sequences of this scenario. The results indicate that the test generation approaches fully achieved the goal of automation. Furthermore, the repeatability rate of the generated test sequences was reduced by 75% with the algorithm proposed in this paper compared with the available depth first search algorithm (DFS), and the test cases covered all the related criterions in CTCS-3 Train Control System Function Requirements Specification (FRS).
  Authors: Liang, Ci; Zheng, Wei
  Authors: Liang, Ci; Zheng, Wei
  Year: 2013
  Document Type: Paper
  Subject: Railroads; Rail
  Session: 553
  Paper Number: 13-0757
• Development of Railway Capacity Cost and Apportionment Model
  Abstract: In 1991 the European Community issued regulations for liberalizing the European railway market by introducing open access. While open access has only been partly implemented so far, the concept of railway path pricing has been well established and is used throughout Europe. Railway path prices should help pay for construction, maintenance and operation of railway infrastructure and help guide transport decisions. Railway path pricing systems are continuously under development and capacity aspects are becoming increasingly important. In this research a capacity based cost allocation method was developed and evaluated using case study data. This showed the impact of three common allocation schemes forapportioning the costs of lost capacity. The paper presents results of this evaluation and outlines whether and how such a capacity-based cost allocation method could be introduced realistically in a path pricing system.
  Authors: Frank, Patrick; Weidmann, Ulrich Alois; Nash, Andrew
  Authors: Frank, Patrick; Weidmann, Ulrich Alois; Nash, Andrew
  Year: 2013
  Document Type: Paper
  Subject: Railroads; Rail
  Session: 553
  Paper Number: 13-1206
• Determination of Criticality of Freight Railroad Infrastructure Based on Flow Optimization under Heavy Congestion
  Abstract: Freight transportation by railroads is an integral part of the U.S. economy. Identifying critical rail infrastructures can help stakeholders prioritize protection initiatives or add necessary redundancy to maximize system resiliency. The criticality of an infrastructure element, link or yard, is based on the increased cost (delay) incurred when that element is disrupted. An event of disruption can cause heavy congestion and the capacity at links and yards should be considered when the fright flow is re-routed. This paper proposes an optimization model for making-up and routing of trains in a disruptive situation to minimize the system-wide total cost, including classification time at yards and travel cost time along the links. Train design optimization seeks to determine the optimal number of trains, their routes, and associated blocks, subject to various capacity and operational constraints at rail links and yards. An iterative heuristic algorithm is proposed to attack the computational burden for real-world networks. The solution algorithm considers the impact of volume on travel time in a congested or near-congested network. The proposed heuristics provide a quality solution with high speed, demonstrated by numerical experiments for small instances. A case study is conducted for the network of a major U.S. Class-1 railroad company based on publicly available data. The paper provides a map showing the criticality of infrastructure in the study area. The heuristic algorithm can also help in managing freight flow in response to a disruptive event.
  Authors: Khaled, Abdullah A.; Jin, Mingzhou; Clarke, David B.; Hoque, Mohammad A.
  Authors: Khaled, Abdullah A.; Jin, Mingzhou; Clarke, David B.; Hoque, Mohammad A.
  Year: 2013
  Document Type: Paper
  Subject: Railroads; Rail
  Session: 553
  Paper Number: 13-1679
• Combinatorial Auctions of Track Capacity in Vertically Separated Markets
  Abstract: This paper addresses the problem of allocating residual track capacity among multiple competing carriers where infrastructure ownership and train operations are vertically separated to facilitate the delivery by train of one-off loads. A bid set construction approach is proposed for use within a combinatorial auction-based framework to support this allocation of track capacity among competing carriers. The proposed bid set construction technique employs an OR-of-XOR bidding language and optimization methods that will ultimately produce newly scheduled trains with minimum total delay and operating costs. The technique enables the expression of complementary or substitutable relationships among the train slots constructed along predetermined train routes and permits quick configuration of routes from residual track capacity along which new trains can be operated. The proposed technique is compared against an intuitive, combinative bid set construction method and is tested within the combinatorial auction-based track capacity allocation framework. A winner determination problem (WDP) that simultaneously accommodates bidding languages of both bid set construction techniques is used to generate an optimal allocation of track capacity among bidders based on the different bidding strategies. Results of computational experiments designed to illustrate the efficiency of the proposed bid construction technique and effectiveness of the framework are presented.
  Authors: Kuo, April; Miller-Hooks, Elise
  Authors: Kuo, April; Miller-Hooks, Elise
  Year: 2013
  Document Type: Paper
  Subject: Railroads; Rail
  Session: 553
  Paper Number: 13-2249
• Capacity Utilization in European Railways: Who Is the Fairest of Them All?
  Abstract: At the strategic level, railways currently use different indices to estimate how ‘value’ is generated by using railway capacity. However, railway capacity is a multidisciplinary area, and attempts to develop various indices cannot provide a holistic measure of operational efficiency. European railways are facing a capacity challenge which is caused by passenger and freight demand exceeding the track capacity supply. In the absence of a comprehensive railway capacity manual, methodologies are needed to assess how well railways use their track capacity. This paper presents a novel and unprecedented approach for this aim. Relative operational efficiency of 24 European railways in capacity utilization is studied for the first time by data envelopment analysis (DEA). It deviates from previous applications of DEA in the railway industry that are conducted to analyze cost efficiency of railways. Six DEA models quantify various aspects of micro, macro and quality of railway capacity utilization in these countries. New inputs like gross domestic product, population and area of the country help to provide a better picture of the status of railways. Passenger satisfaction data about different aspects of railway services in European countries has recently been quantified by European commission and are used for the first time in the literature. Invaluable insights can be inferred from the results which can provide a ground basis for railway practitioners and policy makers.
  Authors: Khadem Sameni, Melody; Landex, Alex
  Authors: Khadem Sameni, Melody; Landex, Alex
  Year: 2013
  Document Type: Paper
  Subject: Railroads; Rail
  Session: 553
  Paper Number: 13-5357
• Automated Generation of Test Cases and Sequences Based on Path Optimization Algorithm
  Authors: Liang, Ci
  Authors: Liang, Ci
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Rail
  Session: 553
  Paper Number: 13-0757
• Development of Railway Capacity Cost and Apportionment Model
  Authors: Frank, Patrick
  Authors: Frank, Patrick
  Year: 2013
  Document Type: Presentation; Poster
  Subject: Rail
  Session: 553
  Paper Number: 13-1206