European Rail Traffic Management System Research Articles

How to steer evolution of a system‐of‐systems

AbstractThis paper presents a system‐theoretic study of how System‐of‐Systems (SoS) evolution can be steered towards any desirable direction. For practitioners, this is a non‐trivial undertaking because of the potential resistance to change from the independent constituents. In this paper, we highlight this subject as a gap in the literature on SoS evolution, but not only. We review the characteristics of the SoS evolution context to establish that, despite the limitations in visibility and control, a SoS will still exhibit many evolutionary tendencies and dynamics, which can be harnessed for steering its evolution. Based on that, we present a set of six 6 prescriptive heuristics which practitioners can turn to when they need a SoS to move in any desired direction. These heuristics optimize for making the best use of one's available (direct and indirect) leverages. The usefulness and broad applicability of the proposed heuristics are illustrated through case studies of two distinct real‐world SoSs, namely, the Internet and the European Rail Traffic Management System (ERTMS).

Railway Signal Digitalization with the European Rail Traffic Management System and Positive Train Control: Industry 4.0 Expectations and Reality

Positive train control (PTC) and the European Rail Traffic Management System (ERTMS) are digital railway signal systems in North America and Europe, respectively. They are frequently described as interchangeable, but they are not. This paper explains the history and motivations for each continent, and the general technical and capability differences between the two signal systems. In general, North America revised their signal systems to respond to safety concerns, and Europe committed to replacing their signals to encourage cross-border train traffic. The ERTMS is significantly more expensive than PTC, and the cost has been justified with expectations of greater capacity. Multiple studies find no basis for large capacity increases after implementation of the ERTMS. In addition, the added cost of the ERTMS threatens an already weak rail freight market in Europe.

A survey on wireless-communication vulnerabilities of ERTMS in the railway sector

Railways represent a critical infrastructure in modern societies. In the past few years, cyber attacks on these infrastructures have been rising, and there is a need to properly analyze the vulnerabilities of field devices. This work focuses on the wireless communication that is defined in the European Rail Traffic Management System standard and proposes a survey of the vulnerabilities of the main employed protocols. Also, it provides some research lines. This study shows how several issues still exist within wireless communication in the railway sector.

Services interfaces for interoperability of signaling computer interlocking on borders

<p>Technological developments in the field of railway signaling have allowed more and more flexibility in the management of rail traffic, especially with computer interlocking. However, differences in signaling principles from one country to another as well as differences in the structure of interlocking software and communication protocols depending on suppliers lead to interoperability difficulties at the borders between computer interlocking. Some deployed projects deal with interoperability issues regarding the communication of signaling information between the train and interlocking like the European rail traffic management system (ERTMS) project. Unfortunately, the interoperability between interlocking themselves is still not achieved. Some deployed projects deal with interoperability issues regarding the communication of signaling information between the train and interlocking like the ERTMS project. Unfortunately, the interoperability between interlocking themselves is still not achieved. This article draws up a proposed model for interfacing at the interlocking boundaries based on service-oriented architecture (SOA). In addition, to ensure the coupling of SOA services to the internal functions of the signaling computer interlocking, a distributed architecture of programmable logic controller according to the IEC 61499 standard is suggested.</p>

Comparative analysis of the functionality of centralized and distributed LEU

This article addresses the centralized LEU (Lineside Electronic Unit) encoder used in ERTMS/ETCS Level 1 (European Rail Traffic Management System / European Train Control System). It is explained what a centralized LEU encoder is and why this solution offers more possibilities than a distributed approach. Also explained the general principle of the encoder and how it works with switchable Eurobalise. The paper also juxtaposes how it works with and connects to the interlocking system in both the distributed and centralized approaches. The differences between the centralized and decentralized LEU encoder in diagnostic and management capabilities are also described.

Effect of Train-Driving Simulator Practice in the European Rail Traffic Management System: An Experimental Study

Many European train drivers face major changes in their work with the introduction of the new train-protection system, the European Rail Traffic Management System (ERTMS), as information retrieval shifts from outside to in-cab, and a new rulebook is introduced. Therefore, many train drivers have to be educated in a short time, to make the transition safe and efficient. The purpose was to find out how a successful ERTMS practice can be designed in a physically low-fidelity but highly functional train-driving simulator. An experimental design was used, with 16 drivers divided into two groups: one group practiced in a simulator, and the other in reality. Standard training methodology was used, and the learning outcome was assessed by both measuring driving errors and via instructor evaluation of a simulator test. The drivers also filled in a questionnaire to capture how different factors, such as repeated practice, experience, and self-estimated confidence, correlate with performance. Results show that the simulator group committed significantly fewer driving errors and received significantly higher scores from the instructor. In addition, the simulator group's better performance is mostly caused by the possibility of repeated training of different special cases. The findings also imply that several of the more common special cases on the ERTMS can hardly be provoked in real train driving. Furthermore, this work strengthens the theory that novices can hardly estimate their own ability. Therefore, we argue that this type of low-fidelity simulator is well suited for research purposes, for practicing special cases, and for train operation companies to assess drivers’ skills.

Communication Transport Protocol Strategies for Rail Applications

Current technologies for managing rail traffic such as the Global System for Mobile communications for Railway (GSM-R) will be no longer be available within the upcoming years. The European Shift2Rail Joint Undertaking (S2R-JU) proposed the Adaptable Communication System (ACS) to overcome this problem. In this work, we model the ACS by abstracting it at the Internet Protocol (IP) level, using tunnels for datagrams’ transmission as a communication bearer is available along the rail. Then, to evaluate its performance, an ACS emulator has been implemented. The core part of it is a Tunnel Manager which can establish pseudo-virtual circuits through multi-bearer tunnels, forcing datagrams on a service-basis to follow specific paths between gateways (i.e., from on-board to a train to the network-side rail control center and vice versa). The Tunnel Manager can properly select a given tunnel/bearer for sending messages (and duplicating them on redundant paths) of critical rail applications for train traffic management, relying on tunnels based on either connection-oriented protocol (i.e., the Transport Control Protocol, TCP), connectionless protocol (i.e., the User Datagram Protocol, UDP) or a mix of them. In this paper, we investigate the best solutions in terms of transport protocols for implementing tunnels through the bearers. Results are based on two main use cases: i. the position report/movement authority messages for the European Rail Traffic Management System (ERMTS) and ii. the critical file transmission, considering either TCP or UDP as tunnel transport protocol. For the first rail application, one UDP bearer can be selected only if the end-to-end channel delay is lower than 100 ms and the experienced packet loss is lower than 4% in the whole crossed network. Two UDP bearers, one TCP bearer or two mixed UDP/TCP bearers should be selected in case the channel delay is greater than 300 ms and the experienced packet loss is greater than 15%. Considering the critical file transfer in the rail scenario, TCP should be selected with two bearers to have a throughput greater than 50 Mbit/s even for a packet loss of 1%.

Fulfilment of the Essential Requirements of the Control-command and Signalling Trackside Subsystem on the Railway Infrastructure of Transhipment Terminals

The implementation of many railway investments indicates as the main goal increasing the efficiency of the railway system, and thanks to its features it becomes easier to integrate it in the competitive transport market. Increasing the integration of the transport sector is one of the cornerstones of the completion of the internal market and rail is an important part of the transport sector moving towards sustainable mobility. The modernized railway lines, which are part of the Trans-European Transport Network (TEN-T) or European Rail Traffic Management System (ERTMS) corridors, also constitute the network of rail freight corridors (RFC). Pursuant to the requirements of European law, setting the dates for implementing interoperability, the infrastructure of comprehensive networks will be forced to adapt to these requirements. Using the example of the control-command and signalling subsystem, this article outlines the scale of the problem related to the implementation of interoperability in relation to rail-road terminals constituting the comprehensive network of the RFC network. Keywords: core network, comprehensive network, certification, control-command and signalling subsystem, ETCS, GSM-R

Analysis of the possibility of implementing interoperability tests on Polish railways

Ensuring the greatest possible interoperability of rail transport, especially for railways in Europe, is one of the key projects to be implemented using the European Rail Traffic Management System (ERTMS), including the European Train Control System (ETCS) and the Global System for Mobile Communications-Railways (GSM-R). The ERTMS system aims to replace many different rail traffic control systems with one, common and unified European solution (Commission Regulation (EU) 2016/919, 2016), (Directive (EU) 2016/797, n.d.). Its creation was dictated by the desire to standardize the traffic control systems present in the territories of various European countries, at the same time extending their functionality and eliminating the existing technical barriers. The aim of this article is to present the possibility of implementation interoperability tests - IOP tests, on Polish railways. These tests are intended to provide a faster, more accurate and less costly demonstration of compliance with the ETCS interoperability requirements compared to field tests. The work defines the concept of interoperability tests as well as the purpose of their application. The general principles and procedures for conducting interoperability tests are presented. In the further part of the work, the operation of laboratories in the European Union is analysed. The laboratories functional in Switzerland and Spain were selected for this analysis. Following, the paper presents the validity of implementing interoperability tests on the territory of the Republic of Poland. On the basis of the pan-European procedure of conducting interoperability tests and the experience of foreign independent laboratories, conditions for the implementation of tests in the Polish railways were developed, which could be used in the future to introduce IOP tests in Poland.

Train driver experience: A big data analysis of learning and retaining the new ERTMS system

Now and in the coming years a new European Rail Traffic Management System (ERTMS) is being deployed on a larger scale. In the system level chosen in the Netherlands (Level 2) lineside signals will disappear and the train driver will receive all information needed for safe and efficient train operation through an interface inside the train cab. Furthermore, procedures, driving skills and communication will alter. Many train drivers will thus need to be trained in driving with ERTMS. Train operating companies (TOC) have to decide on efficient and effective strategies to organise this extensive training volume and to reassure that drivers become and remain proficient after training when roll-out of ERTMS may not have been fully completed.In this paper the central questions to be answered are: How many hours/duties does a driver have to do during a certain period of time on an ERTMS track section to become proficient with ERTMS (learning period), and to stay proficient (retaining period)?The approach taken is unique for rail industry (to the authors' knowledge) and is based on big data analyses. In this study, we were able to study the collective performance of train drivers, by big data analysis while at the same time maintaining privacy through pseudonymisation of the train driver database and their individual performances, characteristics and other potential privacy sensitive data. Databases containing detailed information on all planned and accomplished train service times/positions of the last three years (2015–2017) of a large TOC were combined with personal data from HR databases (age, experience, ERTMS training history, job assessment results, etcetera). From the data, delays caused by rolling stock and train operating related issues were identified. The amount and duration of these delays were correlated with the personal data to test research hypotheses. Again, at the same time we maintained privacy of the individuals’ personal data.Although the research has some limitations due to the small amount of existing ERTMS lines, and associated rolling stock, the results show some clear correlations. Thus, quantifiable directions to the minimum amount of ERTMS driving per 3 months during the first year and in the years after are presented. The results are now being translated into models for training and rostering related to the phase of ERTMS roll-out.

Development of mobile communication systems for high-speed railway

Development of high-speed railways set up challenges for new communication technologies. With the increase in speed, new requirements for communication systems have emerged that HSR requires greater reliability, capacity and shorter response time for efficient and safe operations. Mobile communication systems are crucial for the competitiveness of the railway industry and therefore have become one of the priorities addressed by the participants in the railway system to take advantage of technological opportunities to improve operational processes and the quality of provided transport services. The European Rail Traffic Management System (ERTMS) uses the Global System for Mobile Communications for Railways (GSM-R) for voice and data communication to communicate between trains and control centers. The International Railway Union is exploring new ways of communicating for high-speed railways because as speed increases this system becomes unreliable in information transmission. This paperwork presents an analysis of the evolution of communications on European railways since the usage of GSM-R. In addition, an overview of the various alternative solutions proposed during the time (LTE-R, Future Railway Mobile Communication System) as possible successors to GSM-R technology is given.

Toward Formal Safety and Performance Evaluation of GNSS-based Railway Localisation Function

European Train Control System (ETCS) is the signalling and control component of the European Rail Traffic Management System (ERTMS). This system is essential to guarantee the safe and interoperable operation of trains. To enhance the competitiveness of rail transport services, the introduction of innovative solutions are under study in view of the evolution of ETCS. In this context, the adoption of Global Navigation Satellite System (GNSS) for train localization is investigated as a technology which can ensure an undeniable added value for railways. Yet, a main challenge is to provide safety evidence permitting the certification of these new systems. In particular, the classical safety analysis approaches show limitations in dealing with the complexity of such systems. Therefore, more adapted safety and performance analysis techniques have to be elaborated. In this paper, a model-based approach, adapted for the evaluation of GNSS-based localisation systems in railway, is presented. Considering the safety-critical aspect of the localisation function in railways, formal methods which are based on rigorous mathematical foundations are adopted in the present work. Concretely, a set of formal models are elaborated to ensure a modular representation of trains dynamics in the context of GNSS-based localization. Namely, probabilistic timed automata formalisms are adopted to this aim. Such notations allow for considering stochastic and dynamic aspects, so as to reflect reality in a trustworthy way. The safety and performance properties to be checked can then be formulated by means of temporal logics. Finally, the analysis of such features can be achieved by means of model-checking and simulation techniques. This evaluation phase yields both qualitative and quantitative results and allows for assessing the impact of various parameters and functional choices on both safety and performance. UPPAAL-SMC engine was used to set the tooling chain of our approach, and an illustration considering specific operational test cases is provided.

High density European Rail Traffic Management System (HD-ERTMS) for urban railway nodes: The case study of Rome

The ERTMS (European Rail Traffic Management System) system has been created to standardize the European railway signals and to improve the performance of the railway network. Nowadays the growing rail traffic demand has carried to the congestion of the railway nodes, which turn out to be the bottle necks of the railway infrastructure. The High-Density European Traffic Management System (HD-ERTMS) has been developed as a solution to resolve this problem because, being perfectly superimposable to the Italian national signalling system, it can be applied without changing the current infrastructure. This paper describes the benefit that it will possible to reach by introducing this new signalling system analyzing the case study of the railway node of Rome.

An Eco-Driving Algorithm for Interoperable Automatic Train Operation

The new Automatic Train Operation (ATO) system over the standard European Rail Traffic Management System (ERTMS) will specify the requirements that an automatic train driving system must fulfil in order to be interoperable. The driving is defined by target times located along the journey that are received from the trackside system. Then, the on-board equipment drives the train with the objective of meeting all of the target times. The use of eco-driving methods to calculate the train driving is necessary, as one of the main goals of modern train driving systems is to increase the energy efficiency. This paper presents a simulation-based optimisation algorithm to solve the eco-driving problem constrained by multiple target times. This problem aims to minimize the energy consumption subject to a commercial running time, as the classical eco-driving problem, and also to meet intermediate target times during the journey between stations to enable automatic traffic regulation, especially at junctions. The algorithm proposed combines a Differential Evolution procedure to generate possible solutions with a detailed train simulation model to evaluate them. The use of this algorithm makes possible to find accurate speed profiles that meet the requirements of multiple time objectives. The proposed Differential Evolution algorithm is capable of finding the feasible speed profile with the minimum energy consumption, obtaining a 7.7% of energy variation in the case of a journey with one intermediate target time and 3.1% in the case of two intermediate targets.

Selected Aspects of Control-Command and Signalling On-Board Subsystem Verification

This article describes the procedures, standard parameters and control requirements to be performed in order to achieve EC verification of a Control-Command and Signalling On-board Subsystem. An analysis of issues related to the assessment of the on-board subsystem is presented in terms of the necessary checks that must be performed by a notified body and the issues of interoperability tests of the on-board ERTMS with track-side infrastructure. Providing railway interoperability is strictly related to the introduction of unified rules for the assessment and verification of the ETCS and GSM-R subsystems that are part of the European Rail Traffic Management System (ERTMS). The article describes procedures, standard parameters, requirements and necessary controls that must be implemented to carry out EC Verification of a Control-Command and Signalling On-board Subsystem. Reference is also made to the issues of ERTMS on-board compatibility tests with track-side infrastructure. Keywords: TSI, CCO, ERTMS, conformity assessment, interoperability

Introduction to special section on the ABZ 2018 case study: Hybrid ERTMS/ETCS Level 3

This paper introduces the topic of the Special Section on the ERTMS Level 3 Hybrid case study. The European Rail Traffic Management System (ERTMS) is a system of standards for management and interoperation of signalling for railways. The case study focuses on the ERTMS Level 3 Hybrid principles, which accommodates different types of trains, including trains equipped for ERTMS and non-ERTMS trains. The Special Section contains seven contributed articles describing the application of a formal method to the case study and these contributions are outlined. A overview of the assumptions and requirements of the case study are presented at a level of detail sufficient for the reader to follow the contributed articles.

Formalising the Hybrid ERTMS Level 3 specification in iUML-B and Event-B

We demonstrate refinement-based formal development of the hybrid, ‘fixed virtual block’ approach to train movement control for the emerging European Rail Traffic Management System (ERTMS) level 3. Our approach uses iUML-B diagrams as a front end to the Event-B modelling language. We use abstraction to verify the principle of movement authority before gradually developing the details of the Virtual Block Detector component in subsequent refinements, thus verifying that it preserves the safety properties. We animate the refined models to demonstrate their validity using the scenarios from the Hybrid ERTMS Level 3 (HLIII) specification. We reflect on our team-based approach to finding useful modelling abstractions and demonstrate a systematic modelling method based on the state and class diagrams of iUML-B. The component and control flow architectures of the application, its environment and interacting systems emerge through the layered refinement process. The runtime semantics of the specification’s state-machine behaviour are modelled in the final refinements. We discuss how the model could be used to generate an implementation using code generation tools and techniques.

The Missing Link in the Realization of the African Integrated High-Speed Railway Network: Rules on Technical Standards and Operation

One of the major objectives of the African Union (AU) is to develop an integrated high-speed railway network connecting major African cities for improved continental trade and competition. This paper provides an overview of the main technical aspects of high-speed railway lines with special focus on cross-border operational and technical interoperability. It briefly describes the missing link in realizing a truly interoperable high-speed railway network for the African case. It introduces the technical aspects of railway lines that must be unified for cross-border operation. It also outlines the reasons that may explain the global success of the European Rail Traffic Management System (ERTMS), offering the author’s view on factors that continue to influence decision making in favor of ERTMS over other national and not interoperable solutions such as the Chinese Train Control System (CTCS). The paper concludes by suggesting the way forward for combined continental effort to realize the African Integrated High-Speed Railway Lines Network as part of the African Union’s Agenda 2063.

A Multi-Criteria Decision-Making Framework for the Evaluation of Train Control Information Systems, the Case of ERTMS

The huge potential offered by the implementation of a modern Train Control Information System (TCIS) could result in significant improvements in the railway sector in general. As a technology transfer, primarily in the European railway sector, the European Rail Traffic Management System (ERTMS) is expected to play an important role in providing better railway performances. However, the implementation of ERTMS entails certain dilemmas and disadvantages and the decision-making regarding it can be one of the crucial challenges for each railway. Having this in mind, the aim of this work is to propose a decision-making framework to support such a critical decision process through application of Strengths, Weaknesses, Opportunities, and Threats (SWOT) and Analytic Hierarchy Process (AHP) analyses. In the proposed approach, external and internal factors that simultaneously enhance and constrain ERTMS implementation were identified and presented through the SWOT analysis, while the AHP method was applied for the evaluation of the importance of identified factors. The thorough literature review represents a basis for creating a SWOT matrix and setting of judgments for the evaluation of the SWOT factors. The results of the AHP method highlight the importance of the factors within the SWOT matrix regarding ERTMS implementation. Results of the AHP method were checked by two additional weight assessments in order to provide the appropriate approach for factor evaluation. The proposed approach also shows a relatively simple and very suitable decision-making framework for consideration of other TCISs, too.

A Framework for Vulnerability Detection in European Train Control Railway Communications

Railway systems have evolved considerably in the last years with the adoption of new communication technologies. Aiming to achieve a single European railway network, the European Rail Traffic Management System (ERTMS) emerged in Europe to substitute multiple and noninteroperable national railway communication systems. This system and its security strategies were designed in late 1990s. Recent works have identified vulnerabilities related to integrity, authenticity, availability, and confidentiality. In the context of defining effective countermeasures to mitigate potential vulnerabilities, these vulnerabilities have to be analysed. In this article we introduce a framework that attempts to challenge ERTMS security by evaluating the exploitability of these vulnerabilities.