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J. Aoun

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Abstract (2025) - Joelle Aoun
The research addresses the deployment of new systems that can enhance railway operational capacity and efficiency. The research introduces a framework to support the analysis and strategic development of railway systems. It applies interdisciplinary approaches to complex decision-making, including market potential assessment, decision-making, and scenario-based roadmapping. The analysis was showcased for Moving Block (MB) and Virtual Coupling (VC) railway signalling technologies and is developed further for application to other systems. The developed framework provides a coherent and holistic architecture within the development and evolution of systems where step-changes can be explored, mapped and interpreted based on distinct scenarios and specific project context. It can also foster business growth and organizational changes. The study evaluates the railway system’s attractiveness across railway segments. The goal is to promote a shift from other transport modes to rail, ultimately leading to reduced road traffic congestion and CO2 emissions. Further, a Multi-Criteria Analysis (MCA) offers a comparison among alternatives across multiple criteria like cost, capacity, energy consumption, and regulatory approval. Findings reveal that the integration of SWOT, MCA, expert judgement, gap analysis and scenarios within the framework provides a means for addressing corporate challenges and exploring new application opportunities, even in low-developing countries. Finally, the study provides a detailed roadmap, showing how the implementation of railway systems can maintain efficient operation even under degraded conditions. This comprehensive study equips railway practitioners with strategic planning tools and implementation roadmaps for deploying new railway systems and advancing rail technology amidst growing railway demand. ...
Journal article (2024) - Joelle Aoun, Rob M.P. Goverde, Roberto Nardone, Egidio Quaglietta, Valeria Vittorini
Moving Block (MB) and Virtual Coupling (VC) rail signalling will change current train operation paradigm by migrating vital equipment from trackside to onboard to reduce train separation and maintenance costs. Their actual deployment is however constrained by the industry's need to identify configurations of MB and VC signalling equipment which can effectively guarantee safe train movements even under degraded operational conditions involving component faults. In this paper, we analyse the effectivity of MB and VC in safely supervising train separation under nominal and degraded conditions by using an innovative approach which combines Fault Tree Analysis (FTA) and Stochastic Activity Networks (SAN). An FTA model of unsafe train movement is defined for both MB and VC capturing functional interactions and cause-effect relations among the different signalling components. The FTA is used as a basis to apportion signalling component failure rates needed to feed the SAN model. Effective MB and VC train supervision is analysed by means of SAN-based simulations in the specific scenario of an error in the Train Position Report (TPR) for five rail market segments featuring different traffic characteristics, namely high-speed, mainline, regional, urban and freight. Results show that the thresholds of the design variables depend on the considered signalling system alternative and the investigated market segment. In particular, the TPR delay threshold allowed for MB is higher than for VC. This means that to ensure a safe train movement, VC cannot absorb a TPR delay of longer than 1.5 s, which corresponds to the mainline market segment. For MB instead, the results show that the maximum TPR delay can reach 3.9 s for high-speed and freight railways. In addition, results showed that the integration of an FTA in a SAN model can provide a better understanding of the safety-performance behaviour of a system where VC showed a higher number of braking indications with respect to MB for the same TPR error failure rate. This means that for VC to effectively supervise the train separation at the same safety level as MB, we would need to have a much higher reliability of the TPR. The overall approach can support infrastructure managers, railway undertakings, and rail signalling suppliers in investigating the effectiveness of MB and VC to safely supervise train movements in scenarios involving different types of degraded conditions and failure events. The proposed method can hence support the railway industry in identifying effective and safe design configurations of next-generation rail signalling systems. ...
Abstract (2023) - Joelle Aoun, Rob M.P. Goverde, Roberto Nardone, Egidio Quaglietta, Valeria Vittorini
Moving Block (MB) and Virtual Coupling (VC) rail signalling will change current train operation paradigm by migrating vital equipment from trackside to onboard to reduce train separation and maintenance costs. Their actual deployment is however constrained by the industry’s need to identify confi gurations of MB and VC signalling equipment which can eff ectively guarantee safe train movements even under de-graded operational conditions involving component faults. In this paper, we analyse the eff ectivity of MB and VC in safely supervising train separation under nominal and degraded conditions by using an innovative approach which combines Fault Tree Analysis (FTA) and Stochastic Activity Network (SAN). A FTA model of unsafe train movement is defi ned for both MB and VC capturing functional interactions and cause-eff ect relations among the diff erent signalling components. The FTA is then used as a basis to apportion signalling component failure rates needed to feed the SAN model. Eff ective MB and VC train supervision is analysed by means of SAN-based simulations in the specifi c scenario of an error in the Train Position Reporting (TPR) for fi ve rail mar-ket segments featuring diff erent traffi c characteristics, namely high-speed, mainline, regional, urban and freight. Results show that the overall approach can support infra-structure managers, railway undertakings, and rail system suppliers in investigating ef-fectiveness of MB and VC in safely supervising train movements in scenarios involving diff erent types of degraded conditions and failure events. The proposed method can hence support the railway industry in identifying eff ective and safe design confi gura-tions of next-generation rail signalling systems. ...
Journal article (2023) - Joelle Aoun, Egidio Quaglietta, Rob M.P. Goverde
Developments in the railway industry are continuously evolving and long-term transition strategies can enable an efficient implementation of signalling technologies that provide a significant increase in network capacity and operation efficiency. Virtual Coupling (VC) advances moving block signalling by further reducing train separation to less than an absolute braking distance using train-to-train communication and cooperative train control within a Virtually-Coupled Train Set (VCTS). This paper proposes a method to develop scenario-based roadmaps based on a SWOT and hybrid Delphi-AHP multi-criteria analysis. Step-changes are identified and initially assessed in a Swimlane based on priorities and time order collected from stakeholders through a survey and further developed in a workshop. Optimistic and pessimistic scenarios are assessed regarding various factors and timelines. Step-changes are initially defined in a Swimlane and then enriched with optimistic and pessimistic scenarios to ultimately derive scenario-based roadmaps. Durations for each of the step-changes are developed into scenario-based roadmaps that can be used as an efficient tool for stakeholders to identify and solve potential criticalities/risks to the deployment of VC as well as to setup investment and development plans. The approach is applied to deliver implementation roadmaps of VC for different market segments with particular focus on mainline railways. ...
Journal article (2023) - Ziyulong Wang, Joelle Aoun, Christopher Szymula, Nikola Bešinović
The COVID-19 pandemic has imposed a dramatic effect on the mobility habits of both passengers and freight in the rail sector. Since the relaxation of COVID-19 restrictions worldwide, rail transport has been revitalised gradually. However, the new normal emerges with unprecedented issues, such as changed travel behaviour, lost profits, and a lack of personnel. In this paper, we determine the arising challenges due to COVID-19 and pandemics in general and subsequently propose several solutions to tackle these challenges in rail transport. These solutions cover multidisciplinary aspects such as passenger demand management, freight demand management, service design, automation, decentralisation and advanced railway technologies. By reviewing the relevant literature on COVID-19, public transport and particularly rail transport, we synthesise and identify promising lines of research that should devote more attention to a more efficient, effective and sustainable rail transport service. This paper provides policymakers, researchers, railway infrastructure managers and undertakings with an overview and an outlook for the impacts of the pandemic crisis and similar situations. It supports decision-making with more evidence and facilitates rail transport to restore its performance and reach its societal goal. ...
Doctoral thesis (2023) - J. Aoun
As the deployment of new railway technologies requires official approval from local authorities and governmental agencies, a well-specified strategy can foster investment decisions for technological developments and the overall system migration process. Therefore, it is crucial to guarantee that the proposed railway technologies can enhance operational efficiency and ensure safety to passengers and freight transport. Next-generation train-centric signalling systems can provide substantial capacity benefits to railway undertakings. Moving Block (MB) or the European Rail Traffic Management System / European Train Control System Level 3 (ERTMS/ETCS L3) is a radio-based system without any trackside equipment. A Radio Block Centre (RBC) receives positions of each train continuously and computes a Movement Authority (MA) to each of them. In this signalling system, the track is not partitioned into fixed blocks as is the case in conventional railways but the trains operate under “moving blocks” with a safe distance in front determined by the absolute braking distances. As there is no available trackside equipment, it is vital that trains guarantee their integrity by means of a Train Integrity Monitoring (TIM) system. Virtual Coupling (VC) is one of the most advanced train-centric signalling concepts that drastically reduces train headways and allows trains to move synchronously together in platoons using Vehicle-to-Vehicle (V2V) communication. However, several uncertainties arise in the safety validation and feasibility (from the technical, financial and regulatory perspectives) of the VC technology, particularly when compared to MB. This thesis aims at developing methodological frameworks to support science and the industry in analysing, assessing and developing new complex systems and next-generation rail technologies. The proposed frameworks use interdisciplinary approaches to address complex decision-making processes such as market potential analysis, impact assessment and roadmapping. In addition, a novel methodological framework is proposed to evaluate the safety and performance of technologies and complex systems. We first investigate the market potentials and operational scenarios of VC for different segments of the railway market: high-speed, mainline, regional, urban, and freight trains. The research builds on the Delphi method, with an extensive survey to collect expert opinions about benefits and challenges of VC as well as stated travel preferences in futuristic VC applications. Survey outcomes show that VC train operations can be very attractive to customers of the high-speed, mainline, and regional market segments, with benefits that are especially relevant for freight railways. In particular, customers of regional and freight railways are observed to be unsatisfied with current train services and willing to pay higher fares to avail of a more frequent and flexible service enabled by VC. Operational scenarios for VC are then defined by setting market-attractive service headways and defining characteristics of the rolling stock, infrastructure, and traffic management. A SWOT analysis of strengths and weaknesses of this concept together with business opportunities and threats is carried out. The defined VC future scenario is set to induce a sustainable shift of customers from other travel modes to the railways. Second, we examine the overall impact of next-generation train-centric signalling systems to identify development strategies to face the forecasted railway demand growth. To this aim, an innovative Multi-Criteria Analysis (MCA) framework is introduced to analyse and compare VC and MB in terms of relevant criteria including quantitative (e.g., costs, capacity, stability, energy) and qualitative ones (e.g., safety, regulatory approval). We use a hybrid Delphi-Analytic Hierarchic Process (Delphi-AHP) technique to objectively select, combine and weight the different criteria to more reliable MCA outcomes. The analysis has been performed for different rail market segments including high-speed, mainline, regional, urban and freight corridors. The results show that there is a highly different technological maturity level between MB and VC given the larger number of vital issues not yet solved for VC. The MCA also indicates that VC could outperform MB for all market segments if it reaches a comparable maturity and safety level. The provided analysis can effectively support the railway industry in strategic investment planning of VC. Third, developments in the railway industry are continuously evolving and long-term transition strategies can enable an efficient implementation of signalling technologies that provide a significant increase in network capacity and operation efficiency. VC advances MB signalling by further reducing train separation to less than an absolute braking distance using V2V communication and cooperative train control within a Virtually Coupled Train Set (VCTS). This chapter proposes a method to develop scenario-based roadmaps based on the SWOT and hybrid Delphi-AHP MCA. Step-changes are identified and initially assessed in a Swimlane based on priorities and time order collected from stakeholders through a survey and further developed in a workshop. Optimistic and pessimistic scenarios are assessed regarding various factors and timelines. The step-changes are then enriched with the optimistic and pessimistic scenarios, and associated durations are estimated for each of the step-changes, which finally result into scenario-based roadmaps that can be used as an efficient tool for stakeholders to identify and solve potential criticalities/risks to the deployment of VC as well as to setup investment and development plans. The approach is applied to deliver implementation roadmaps of VC for different market segments with particular focus on mainline railways. Fourth, although MB and VC rail signalling will change the current train operation paradigm by migrating vital equipment from trackside to onboard to reduce train separation and maintenance costs, their actual deployment is constrained by the need for methods to identify configurations which can effectively guarantee safe train movements even under degraded operational conditions. In this thesis, we analyse the effectivity of MB and VC in safely supervising train separation under nominal and degraded conditions by using an innovative approach which combines Fault Tree Analysis (FTA) and Stochastic Activity Network (SAN). An FTA model of unsafe train movement is defined for both MB and VC capturing functional interactions and cause-effect relations among the different signalling components. The FTA is then used as a basis to apportion signalling component failure rates needed to feed the SAN model. Effective MB and VC train supervision is analysed by means of SAN-based simulations in the specific scenario of an error in the Train Position Report (TPR) for five rail market segments featuring different traffic characteristics, namely high-speed, mainline, regional, urban and freight. Results show that the overall approach can support infrastructure managers, railway undertakings, and rail system suppliers in investigating the effectiveness of MB and VC in safely supervising train movements in scenarios involving different types of degraded conditions and failure events. The proposed method can hence support the railway industry in identifying effective and safe design configurations of next-generation rail signalling systems. In summary, this thesis provides multiple scientific contributions to train-centric rail signalling technologies by developing several methodological frameworks to support decision-making towards the development of complex railway systems. With a rapid growth of the railway demand, this thesis serves as a guidance for practitioners to develop more advanced transportation systems while ensuring an improved evaluation of safety and performance. ...
Abstract (2023) - Joelle Aoun, Rob M.P. Goverde, Roberto Nardone, Egidio Quaglietta, Valeria Vittorini
Moving Block (MB) and Virtual Coupling (VC) rail signalling will change current train operation paradigm by migrating vital equipment from trackside to onboard to reduce train separation and maintenance costs. Their actual deployment is however constrained by the industry’s need to identify configurations of MB and VC signalling equipment which can effectively guarantee safe train movements even under degraded operational conditions involving component faults. In this paper, we analyse the effectivity of MB and VC in safely supervising train separation under nominal and degraded conditions by using an innovative approach which combines Fault Tree Analysis (FTA) and Stochastic Activity Network (SAN). A FTA model of unsafe train movement is defined for both MB and VC capturing functional interactions and cause effect relations among the different signalling components. The FTA is then used as a basis to apportion signalling component failure rates needed to feed the SAN model. Effective MB and VC train supervision is analysed by means of SAN-based simulations in the specific scenario of an error in the Train Position Reporting (TPR) for five rail market segments featuring different traffic characteristics, namely high-speed, mainline, regional, urban and freight. Results show that the overall approach can support infrastructure managers, railway undertakings, and rail system suppliers in investigating effectiveness of MB and VC in safely supervising train movements in scenarios involving different types of degraded conditions and failure events. The proposed method can hence support the railway industry in identifying effective and safe design configurations of next-generation rail signalling systems. ...
Conference paper (2022) - Joelle Aoun, Rob M.P. Goverde, Roberto Nardone, Egidio Quaglietta, Valeria Vittorini
Railway systems are complex given their interconnectivity with sub-systems wherein each contains multiple components. Virtual Coupling (VC) is a next-generation railway signalling technology that advances Moving Block (MB), also known as European Train Control System Level 3 (ETCS L3). Some pilot implementations exist for MB. However, VC is still a visionary system and involves several safety issues due to the relative braking distance between trains. Therefore, it is important to evaluate the safety of this system to understand whether it is feasible for deployment. This paper performs a preliminary safety and reliability study by introducing a fault tree (FT) model to investigate the possible causes that lead to an unsafe train movement for MB and VC. To this aim, a FT model is initially built for the MB system, considering the system configurations and interactions between wireless devices, onboard and trackside equipment. Then, the FT model of the VC system is derived on top of the one for MB and the differences are highlighted between the FT elements of the two systems. ...
Journal article (2021) - Joelle Aoun, Egidio Quaglietta, Rob M.P. Goverde, Martin Scheidt, Marcelo Blumenfeld, Anson Jack, Bill Redfern
The railway industry needs to investigate overall impacts of next generation signalling systems such as Moving Block (MB) and Virtual Coupling (VC) to identify development strategies to face the forecasted railway demand growth. To this aim an innovative multi-criteria analysis (MCA) framework is introduced to analyse and compare VC and MB in terms of relevant criteria including quantitative (e.g. costs, capacity, stability, energy) and qualitative ones (e.g. safety, regulatory approval). We use a hybrid Delphi-Analytic Hierarchic Process (AHP) technique to objectively select, combine and weight the different criteria to more reliable MCA outcomes. The analysis has been performed for different rail market segments including high-speed, mainline, regional, urban and freight corridors. The results show that there is a highly different technological maturity level between MB and VC given the larger number of vital issues not yet solved for VC. The MCA also indicates that VC could outperform MB for all market segments if it reaches a comparable maturity and safety level. The provided analysis can effectively support the railway industry in strategic investment planning of VC. ...
Report (2020) - J. Aoun, E. Quaglietta, R.M.P. Goverde, Anson Jack, Marcelo Blumenfeld, Bill Redfern, Gunnar Bosse, Leonhard Pelster, Martin Scheidt, Simon Söser
The present document constitutes Deliverable D4.2 “Cost-Effectiveness Analysis for Virtual Coupling” in the framework of TD2.8 of IP2 according to the Shift2Rail Multi-Annual Action plan (MAAP). This deliverable introduces a Multi-Criteria Analysis framework for assessing impacts of train-centric signalling in the operational, technological and business domains. Specifically, Virtual Coupling (VC) and Moving Block (MB) signalling are compared in terms of eight key criteria and benchmarked with respect to the current state of practice for the different rail market segments identified by the S2R MAAP (i.e. high-speed, main-line, regional, urban and freight). Quantitative criteria include total costs, infrastructure capacity, system stability, travel demand, and energy consumption. In addition, qualitative criteria include public acceptance, regulatory approval, and safety. Consolidated mathematical techniques and engineering methods have been used to assess each of the quantitative criteria while a Delphi approach has gathered values for the qualitative criteria based on extensive Subject Matter Expert (SME) interviews and workshops. A Multi-Criteria Analysis (MCA) has been setup by implementing a hybrid Delphi-Analytic Hierarchic Process (AHP) technique to weight and combine the different criteria in final performance scores of MB and VC signalling. The adopted Delphi-AHP technique has been proven to enhance collaboration among experts in selecting and weighting the criteria by means of an iterative feedback loop ending when consistent weights of relative criteria importance were achieved. The individual analyses of single criteria show that VC outperforms MB for all market segments in terms of infrastructure capacity, system stability, energy consumption and travel demand. VC enables trains to follow each other at a distance shorter than an absolute braking distance, which can reduce headways significantly, especially if trains can move cooperatively in virtually coupled platoons. This is also reflected in terms of system stability and energy given that the advantage of running at a shorter safe separation while continuously being informed about the speed of adjacent trains improves the capability of mitigating delay propagation and enhancing energy efficiency. An increased modal shift to railways is observed for VC, especially for the regional and freight markets where a more flexible train service would better satisfy customer needs currently poorly addressed on those segments. Deployment of VC will be slightly more expensive than MB mostly due to the need of installing ATO and V2V communication while operational costs for the two systems will be comparable. Issues and priorities identified for regulatory approval and public acceptance were judged by SMEs to be very similar for MB and VC. In terms of safety, VC scores lower than MB given the different technological maturity level and the larger number of vital issues yet to be solved. The SMEs assigned a very high importance weight to the safety criterion, which therefore affects greatly the final result of the MCA. The MCA score is hence in favour of MB for all market segments, despite the better performance of VC forsingle criteria like capacity, stability, energy consumption and travel demand. A fairer comparison can be obtained when assuming the same maturity level of MB and VC in a future point in time. In that case, VC clearly outperforms MB for all market segments and for freight and regional in particular, given that the provided train service flexibility would facilitate larger modal shifts of the customer demand. ...
Conference paper (2020) - J. Aoun, E. Quaglietta, R.M.P. Goverde
Virtual Coupling (VC) is a newly introduced concept of train-centric signalling technology that conceives trains to run autonomously in radio-connected platoons. These trains move synchronously at a relative braking distance to significantly improve railway capacity and address the forecasted increase in railway demand. The technical feasibility of VC depends on its strengths, weaknesses, opportunities and threats which can introduce radical changes to current train services, technologies and procedures. This paper investigates demand trends and operational scenarios of future train-centric signalling systems. To this end, stated travel preferences have been collected by means of a survey to have more insight on modal shares in the case of future VC applications. In addition, a Delphi method has been applied where another extensive survey has collected expert opinions about benefits and challenges of VC. Results show that VC can be very attractive to customers of high-speed and main line railways and have special benefits to the regional market where a manifest willing to pay more for using a more frequent train service was found. This concept therefore calls for a deeper understanding of possible Virtual Coupling operational scenarios and the impact on the railway industry. ...
Report (2020) - J. Aoun, E. Quaglietta, R.M.P. Goverde, Joern Pachl, Martin Scheidt, Bill Redfern, Marcelo Blumenfeld
This document constitutes MOVINGRAIL Deliverable D4.3 ‘Application Roadmap for the Introduction of Virtual Coupling’ in the framework of TD2.8 of IP2 according to the Shift2Rail MultiAnnual Action plan (MAAP). This deliverable moves forward the current state of the railways by developing a long-term strategy that will enable a smooth, gradual transition towards the implementation of Virtual Coupling for various market segments. The scope of Virtual Coupling is analysed together with the impact on the technical and operational railway system components of interlocking, communication structures, automatic train protection, automatic train operation, railway traffic planning, and railway traffic management. For each of these components main research and development challenges are derived providing an overview of knowledge gaps and critical step-changes for the development of Virtual Coupling. A clear distinction must be made between VCTS train protection and cooperative train operation, similar to ATP and ATO but then for virtual-coupled trains. A convoy or VCTS is a vital safety system concept that allows virtual-coupled trains to follow each other up to relative braking distances. A convoy can additionally form a platoon, which is a non-vital multitrain control concept that enables (virtually-coupled) trains to move synchronously and stable together. The cooperative train operation system guarantees stable operation in a platoon, while the VCTS train protection system supervises the relative braking distances. A Swimlane roadmap is developed to group step-changes into different themes and categories. This is achieved by means of a quantitative-qualitative gap analysis between current and future states in the operational, technological and business domains. A survey was distributed to stakeholders to collect priorities and time orders for each of the defined steps within the Swimlane roadmap. Optimistic and pessimistic scenarios are defined for each market segment using the SWOT analysis from MOVINGRAIL D4.1 and the cost-effectiveness analysis from MOVINGRAIL D4.2. Optimistic scenarios are based on the estimates made in the ‘White Paper on Transport’ of the European Commission (EC) regarding travel demand and CO2 emissions. Pessimistic scenarios consider a lower growth in the railway demand as well as a higher increase in CO2 emissions and capital and operational costs when compared to the optimistic scenarios (specifically a 50% less increase in rail demand and 50% more increase in CO2 emissions and costs). Scenario-based roadmaps are developed to fulfil the EC’s vision of a more competitive, capacity effective and sustainable railway by 2050. This deliverable is based on the assumption that the strategic goals set by the EC in terms of railway demand, capacity and emissions could be met if Virtual Coupling (VC) operations will be implemented within the target year 2050. Results show that all the considered scenarios and railway market segments could achieve the timely deployment of Virtual Coupling except in the pessimistic scenario for mainline railways where VC could be deployed not earlier than 2054. Critical issues are here the longitudinal motion control systems of the Virtually Coupled Train Sets and the integrated traffic management and cooperative train operation complexity for heterogeneous trains. These scenario-based roadmaps can be used as an efficient tool for stakeholders to identify and solve potential criticalities/risks to the deployment of Virtual Coupling as well as to plan necessary investment/development actions. The developed roadmaps provide a long-term transition strategy defining for each rail market segment a sequence of progressive upgrades to connected and automated railways that will eventually lead to the deployment of Virtual Coupling and enable a significant increase in infrastructure capacity and operation efficiency. ...
Report (2020) - J. Aoun, E. Quaglietta, R.M.P. Goverde, G Nicholson, Joern Pachl, Martin Scheidt, John Chaddock
This document evaluates the attractiveness of Virtual Coupling (VC) for different market segments (high-speed, main line, regional, urban/suburban, freight) and defines operational scenarios for each of them. A SWOT analysis identifies main strengths and weaknesses of the Virtual Coupling concept and corresponding opportunities and threats to each specific railway market segment. The research relies on a Delphi method with an extensive survey of expert opinions and stated travel preferences assuming VC has been implemented. The survey involved subject matter experts of the wide European railway industry including infrastructure managers, railway undertakings, system suppliers, transport authorities, railway institutions, private consultants and academics. In addition, travel preferences have been collected by interviewing European representatives belonging to other socio professional categories. Results show that the implementation of Virtual Coupling can be attractive to customers of high-speed, main line, regional and especially freight segments. Virtual Coupling has the potential of completely changing the way in which such segments operate and attract a modal shift from other transport modes to railways. Customers are even willing to pay higher fares for more frequent and flexible train services, especially on the regional and freight segments which are currently perceived as not satisfactory. Several operational scenarios have been defined based on the outcomes of the survey, setting market-attractive VC service headways for each market segment as well as specifying characteristics of rolling stock, power supply, traffic, and platform crowd management. Principles to couple/decouple convoys of virtually coupled trains are also provided based on the specific network characteristics of the different market segments. A SWOT analysis is presented which builds on the outcomes of the survey, the operational scenarios and brainstorming sessions with experts of the European railway industry. The main strengths identified for VC are a substantial increase in capacity and reduced operational costs with respect to Moving Block while mitigating delay propagation and improving reliability of ground/train communication. On the other hand, weaknesses of this concept refer to the fact that capacity gains at diverging junctions equipped with current switch technologies might be marginal, since here trains still need to be separated by a full braking distance. Also, the implementation of VC operations would require an investment to upgrade the overhead line system, platform lengths (to allow platoons of trains to stop) and possibly the switch technology. An upgrade of the switch technology towards faster and more reliable ones (e.g. Railtaxi and REPOINT) will unleash the full potential of VC operations. Significant opportunities will be brought about Virtual Coupling such as potential increase in the profit of infrastructure managers and operators as well as a deregulation of the current railway market which could be opened also to smaller transport operators due to the increase of available train paths and the decrease of operational costs by full train automation. In addition, the train-to-train communication could lead to the institution of cooperative consortia of railway operators which can be more economically beneficial than the current competitive market model. This would also provide the chance to migrate obsolescent command and control systems towards future-proof digital railway architectures. Possible threats to the introduction of this concept mainly relate to potential increase of train control complexity increasing risks of approval from the railway industry. The need for an initial investment might be not well received by infrastructure managers and local governments. As well as the necessity of partially changing policies, operational procedures and engineering rules currently in place. When overcoming such challenges, Virtual Coupling has potentials to fully revolutionise and improve current train operations so to induce a sustainable shift to railways. ...
Journal article (2020) - Joelle Aoun, Egidio Quaglietta, Rob M.P. Goverde
The new concept of virtual coupling (VC) envisages autonomous trains running in radio-connected platoons to significantly improve railway capacity and address the forecasted increase in railway demand. Such a concept will introduce radical changes to current train services, technologies, and procedures, which calls for a deeper understanding of the possible modes of operation and the impacts on the entire railway business. This paper investigates market potentials and operational scenarios of VC for different segments of the railway market: high-speed, main-line, regional, urban, and freight trains. The research builds on the Delphi method, with an extensive survey to collect expert opinions about benefits and challenges of VC as well as stated travel preferences in futuristic VC applications. Survey outcomes show that VC train operations can be very attractive to customers of the high-speed, main-line, and regional market segments, with benefits that are especially relevant for freight railways. In particular, customers of regional and freight railways are observed to be unsatisfied with current train services and willing to pay higher fares to avail of a more frequent and flexible service enabled by VC. Operational scenarios for VC are then defined by setting market-attractive service headways and by characteristics of the rolling stock, infrastructure, and traffic management. An analysis of strengths and weaknesses of such a concept together with business opportunities and threats is carried out. The defined VC future scenario is set to induce a sustainable shift of customers from other travel modes to the railways. ...
Poster (2019) - J. Aoun, E. Quaglietta, R.M.P. Goverde