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  • 1. Bestill onlineKjøp publikasjonen >>
    Ait Ali, Abderrahman
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Methods for Capacity Allocation in Deregulated Railway Markets2020Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Faced with increasing challenges, railways around Europe have recently undergone major reforms aiming to improve the efficiency and competitiveness of the railway sector. New market structures such as vertical separation, deregulation and open access can allow for reduced public expenditures, increased market competition, and more efficient railway systems.

    However, these structures have introduced new challenges for managing infrastructure and operations. Railway capacity allocation, previously internally performed within monopolistic national companies, are now conferred to an infrastructure manager. The manager is responsible for transparent and efficient allocation of available capacity to the different (often competing) licensed railway undertakings.

    This thesis aims at developing a number of methods that can help allocate capacity in a deregulated (vertically separated) railway market. It focuses on efficiency in terms of social welfare, and transparency in terms of clarity and fairness. The work is concerned with successive allocation of capacity for publicly controlled and commercial traffic within a segmented railway market.

    The contributions include cost benefit analysis methods that allow public transport authorities to assess the social welfare of their traffic, and create efficient schedules. The thesis also describes a market-based transparent capacity allocation where infrastructure managers price commercial train paths to solve capacity conflicts with publicly controlled traffic. Additionally, solution methods are developed to help estimate passenger demand, which is a necessary input both for resolving conflicts, and for creating efficient timetables.

    Future capacity allocation in deregulated markets may include solution methods from this thesis. However, further experimentations are still required to address concerns such as data, legislation and acceptability. Moreover, future works can include prototyping and pilot projects on the proposed solutions, and investigating legal and digitalisation strategies to facilitate the implementation of such solutions.

    Delarbeid
    1. European Railway Deregulation: An overview of market organization and capacity allocation
    Åpne denne publikasjonen i ny fane eller vindu >>European Railway Deregulation: An overview of market organization and capacity allocation
    2022 (engelsk)Inngår i: Transportmetrica A: Transport Science, ISSN 2324-9935, E-ISSN 2324-9943, Vol. 18, nr 3, s. 594-618Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Railway markets in Europe have been reorganized to allow competition between different operators. Thus, European railways have been vertically separated, separating infrastructure management from provisions of train services. This allows several train operators to compete for passengers and freight services. Different ways have emerged for vertical separation, capacity allocation and track access charges. This paper reviews, compares and discusses important deregulation aspects, using examples from a number of European countries to show different possible solutions. The study describes how competition has been introduced and regulated, with a particular focus on describing the different ways capacity is allocated and how conflicting requests by different train operators are resolved. It also reviews the related issue of how access charges are constructed and applied. Although guided by the same European legislation, we conclude that the studied railways have different deregulation outcomes, e.g., market organization, capacity allocation. Besides, few countries have so far managed to create efficient and transparent processes for allocating capacity between competing train operators. Although allowed by the legislation, market-based allocation is absent or never used. In order to foster more competition which can yield substantial social benefits, the survey indicates that most European railways still need to develop and experiment with more efficient and transparent capacity allocation procedures.

    sted, utgiver, år, opplag, sider
    Taylor & Francis, 2022
    Emneord
    Railway deregulation, Vertical separation, Competition, Capacity allocation, Access charges
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-173445 (URN)10.1080/23249935.2021.1885521 (DOI)000621709500001 ()
    Merknad

    Funding: This research is part of the project Socio-economically efficient allocation of railway capacity, SamEff (Samhallsekonomiskt effektiv tilldelning av kapacitet pa jarnvagar) which is funded by a grant from the Swedish Transport Administration (Trafikverket). The authors are grateful to Jan-Eric Nilsson and Yves Crozet for reference recommendations as well as Russell Pittman, Steven Harrod, Roger Pyddoke and several anonymous reviewers for the valuable discussions and comments.

    Tilgjengelig fra: 2021-02-19 Laget: 2021-02-19 Sist oppdatert: 2022-10-17
    2. Pricing commercial train path requests based on societal costs
    Åpne denne publikasjonen i ny fane eller vindu >>Pricing commercial train path requests based on societal costs
    2020 (engelsk)Inngår i: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 132, s. 452-464Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    On deregulated railway markets, efficient capacity allocation is important. We study the case where commercial trains and publicly controlled traffic (“commuter trains”) use the same railway infrastructure and hence compete for capacity. We develop a method that can be used by an infrastructure manager trying to allocate capacity in a socially efficient way. The method calculates the loss of societal benefits incurred by changing the commuter train timetable to accommodate a commercial train path request, and based on this calculates a reservation price for the train path request. If the commercial operator’s willingness-to-pay for the train path exceeds the loss of societal benefits, its request is approved. The calculation of these benefits takes into account changes in commuter train passengers’ travel times, waiting times, transfers and crowding, and changes in operating costs for the commuter train operator(s). The method is implemented in a microscopic simulation program, which makes it possible to test the robustness and feasibility of timetable alternatives. We show that the method is possible to apply in practice by demonstrating it in a case study from Stockholm, illustrating the magnitudes of the resulting commercial train path prices. We conclude that marginal societal costs of railway capacity in Stockholm are considerably higher than the current track access charges.

    sted, utgiver, år, opplag, sider
    Elsevier, 2020
    Emneord
    Train timetables, Train conflicts, Capacity pricing, Railway capacity, Capacity allocation
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-162784 (URN)10.1016/j.tra.2019.12.005 (DOI)000514014700030 ()2-s2.0-85076736383 (Scopus ID)
    Prosjekter
    SamEff
    Merknad

    Funding agencies:  Swedish Transport Administration (Trafikverket) [Samhallsekonomiskt effektiv tilldelning av kapacitet pa jarnvagar]

    The accepted version is also available on the author's home page: 

    http://abdeaitali.github.io/

    Tilgjengelig fra: 2019-12-18 Laget: 2019-12-18 Sist oppdatert: 2021-12-01bibliografisk kontrollert
    3. Are commuter train timetables consistent with passengers' valuations of waiting times and in-vehicle crowding?
    Åpne denne publikasjonen i ny fane eller vindu >>Are commuter train timetables consistent with passengers' valuations of waiting times and in-vehicle crowding?
    2022 (engelsk)Inngår i: Transport Policy, ISSN 0967-070X, E-ISSN 1879-310X, Vol. 116, s. 188-198Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Social cost-benefit analysis is often used to analyse transport investments, and can also be used for transport operation planning and capacity allocation. If it is to be used for resolving capacity conflicts, however, it is important to know whether transit agencies' timetable requests are consistent with the cost-benefit framework, which is based on passenger preferences. We show how a public transport agency's implicit valuations of waiting time and crowding can be estimated by analysing timetables, apply the method to commuter train timetables in Stockholm, and compare the implicit valuations to the corresponding passenger valuations in the official Swedish cost-benefit analysis guidelines. The results suggest that the agency puts a slightly lower value on waiting time and crowding than the passenger valuations codified in the official guidelines. We discuss possible reasons for this and implications for using cost-benefit analysis for capacity allocation. We also find that optimal frequencies are more sensitive to the waiting time valuation than to that of crowding.

    sted, utgiver, år, opplag, sider
    Elsevier, 2022
    Emneord
    Waiting time, Crowding, Cost-benefit analysis, Implicit preference, Commuter train
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-181610 (URN)10.1016/j.tranpol.2021.11.025 (DOI)000751667100001 ()
    Prosjekter
    SamEff
    Forskningsfinansiär
    Swedish Transport Administration
    Merknad

    Funding: Swedish Transport Administration (Trafikverket) [samhadllsekonomiskt effektiv tilldelning av kapacitet pa jadrnvadgar]

    Tilgjengelig fra: 2021-12-03 Laget: 2021-12-03 Sist oppdatert: 2023-01-10bibliografisk kontrollert
    4. A disaggregate bundle method for train timetabling problems
    Åpne denne publikasjonen i ny fane eller vindu >>A disaggregate bundle method for train timetabling problems
    Vise andre…
    2020 (engelsk)Inngår i: Journal of Rail Transport Planning & Management, ISSN 2210-9706, E-ISSN 2210-9714, Vol. 16, artikkel-id 100200Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    The train timetabling problem (TTP) consists of finding a feasible timetable for a number of trains which minimises some objective function, e.g., sum of running times or deviations from ideal departure times. One solution approach is to solve the dual problem of the TTP using so-called bundle methods. This paper presents a new bundle method that uses disaggregate data, as opposed to the standard bundle method which in a certain sense relies on aggregate data. We compare the disaggregate and aggregate methods on realistic train timetabling scenarios from the Iron Ore line in Northern Sweden. Numerical results indicate that the proposed disaggregate method reaches better solutions faster than the standard aggregate approach.

    Emneord
    Train timetabling, Disaggregation, Bundle methods, Lagrangian relaxation, Mathematical programming
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-165781 (URN)10.1016/j.jrtpm.2020.100200 (DOI)000597313000002 ()
    Prosjekter
    SamEff
    Forskningsfinansiär
    Swedish Transport Administration
    Merknad

    The accepted version is also available on the author's home page: 

    http://abdeaitali.github.io/

    Funding agencies: Swedish Transport Administration (Trafikverket)

    Tilgjengelig fra: 2020-05-24 Laget: 2020-05-24 Sist oppdatert: 2021-12-01
    5. The value of additional data for public transport origin–destination matrix estimation
    Åpne denne publikasjonen i ny fane eller vindu >>The value of additional data for public transport origin–destination matrix estimation
    2022 (engelsk)Inngår i: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 14, nr 2, s. 419-439Artikkel i tidsskrift (Fagfellevurdert) Published
    Abstract [en]

    Passenger origin–destination data is an important input for public transport planning. In recent years, new data sources have become increasingly common through the use of the automatic collection of entry counts, exit counts and link flows. However, collecting such data can be sometimes costly. The value of additional data collection hence has to be weighed against its costs. We study the value of additional data for estimating time-dependent origin–destination matrices, using a case study from the London Piccadilly underground line. Our focus is on how the precision of the estimated matrix increases when additional data on link flow, destination count and/or average travel distance is added, starting from origin counts only. We concentrate on the precision of the most policy-relevant estimation outputs, namely, link flows and station exit flows. Our results suggest that link flows are harder to estimate than exit flows, and only using entry and exit data is far from enough to estimate link flows with any precision. Information about the average trip distance adds greatly to the estimation precision. The marginal value of additional destination counts decreases only slowly, so a relatively large number of exit station measurement points seem warranted. Link flow data for a subset of links hardly add to the precision, especially if other data have already been added.

    sted, utgiver, år, opplag, sider
    Springer, 2022
    Emneord
    Dynamic origin-destination; OD estimation; entropy maximization; lagrangian relaxation; smart card; public transport
    HSV kategori
    Identifikatorer
    urn:nbn:se:liu:diva-179343 (URN)10.1007/s12469-021-00282-0 (DOI)000695756100001 ()
    Prosjekter
    SamEff
    Forskningsfinansiär
    Swedish Transport Administration
    Merknad

    Funding: Swedish National Road and Transport Research Institute (VTI); Swedish Transport Administration (Trafikverket)

    Tilgjengelig fra: 2021-09-19 Laget: 2021-09-19 Sist oppdatert: 2022-10-14
    Fulltekst (pdf)
    fulltext
    Download (png)
    presentationsbild
  • 2.
    Ait Ali, Abderrahman
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. VTI Swedish National Road and Transport Research Institute, Transport Economics, Stockholm.
    Eliasson, Jonas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    European Railway Deregulation: An overview of market organization and capacity allocation2022Inngår i: Transportmetrica A: Transport Science, ISSN 2324-9935, E-ISSN 2324-9943, Vol. 18, nr 3, s. 594-618Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Railway markets in Europe have been reorganized to allow competition between different operators. Thus, European railways have been vertically separated, separating infrastructure management from provisions of train services. This allows several train operators to compete for passengers and freight services. Different ways have emerged for vertical separation, capacity allocation and track access charges. This paper reviews, compares and discusses important deregulation aspects, using examples from a number of European countries to show different possible solutions. The study describes how competition has been introduced and regulated, with a particular focus on describing the different ways capacity is allocated and how conflicting requests by different train operators are resolved. It also reviews the related issue of how access charges are constructed and applied. Although guided by the same European legislation, we conclude that the studied railways have different deregulation outcomes, e.g., market organization, capacity allocation. Besides, few countries have so far managed to create efficient and transparent processes for allocating capacity between competing train operators. Although allowed by the legislation, market-based allocation is absent or never used. In order to foster more competition which can yield substantial social benefits, the survey indicates that most European railways still need to develop and experiment with more efficient and transparent capacity allocation procedures.

    Fulltekst (pdf)
    fulltext
  • 3.
    Ait Ali, Abderrahman
    et al.
    The Swedish National Road and Transport Research Institute (VTI), Stockholm, Sweden.
    Eliasson, Jonas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    The value of additional data for public transport origin–destination matrix estimation2022Inngår i: Public Transport, ISSN 1866-749X, E-ISSN 1613-7159, Vol. 14, nr 2, s. 419-439Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Passenger origin–destination data is an important input for public transport planning. In recent years, new data sources have become increasingly common through the use of the automatic collection of entry counts, exit counts and link flows. However, collecting such data can be sometimes costly. The value of additional data collection hence has to be weighed against its costs. We study the value of additional data for estimating time-dependent origin–destination matrices, using a case study from the London Piccadilly underground line. Our focus is on how the precision of the estimated matrix increases when additional data on link flow, destination count and/or average travel distance is added, starting from origin counts only. We concentrate on the precision of the most policy-relevant estimation outputs, namely, link flows and station exit flows. Our results suggest that link flows are harder to estimate than exit flows, and only using entry and exit data is far from enough to estimate link flows with any precision. Information about the average trip distance adds greatly to the estimation precision. The marginal value of additional destination counts decreases only slowly, so a relatively large number of exit station measurement points seem warranted. Link flow data for a subset of links hardly add to the precision, especially if other data have already been added.

    Fulltekst (pdf)
    fulltext
  • 4.
    Ait Ali, Abderrahman
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. Swedish National Road and Transport Research Institute (VTI), Stockholm.
    Eliasson, Jonas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. Swedish Transport Administration (Trafikverket), Solna.
    Warg, Jennifer
    Royal Institute of Technology (KTH), Stockholm.
    Are commuter train timetables consistent with passengers' valuations of waiting times and in-vehicle crowding?2022Inngår i: Transport Policy, ISSN 0967-070X, E-ISSN 1879-310X, Vol. 116, s. 188-198Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Social cost-benefit analysis is often used to analyse transport investments, and can also be used for transport operation planning and capacity allocation. If it is to be used for resolving capacity conflicts, however, it is important to know whether transit agencies' timetable requests are consistent with the cost-benefit framework, which is based on passenger preferences. We show how a public transport agency's implicit valuations of waiting time and crowding can be estimated by analysing timetables, apply the method to commuter train timetables in Stockholm, and compare the implicit valuations to the corresponding passenger valuations in the official Swedish cost-benefit analysis guidelines. The results suggest that the agency puts a slightly lower value on waiting time and crowding than the passenger valuations codified in the official guidelines. We discuss possible reasons for this and implications for using cost-benefit analysis for capacity allocation. We also find that optimal frequencies are more sensitive to the waiting time valuation than to that of crowding.

    Fulltekst (pdf)
    fulltext
  • 5.
    Ait Ali, Abderrahman
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. VTI.
    Eliasson, Jonas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. Trafikverket.
    Warg, Jennifer
    KTH.
    Measuring the Socio-economic Benefits of Train Timetables: Application to Commuter Train Services in Stockholm2017Inngår i: / [ed] Domokos Esztergár-Kiss, Tamás Mátrai, János Tóth, István Varga, 2017, Vol. 27, s. 849-856Konferansepaper (Fagfellevurdert)
    Abstract [en]

    On highly used railway lines with heterogeneous traffic, timetabling is challenging. In particular, the limited existing capacity means that to guarantee an acceptable level of quality, the infrastructure manager must cancel some train services on the expense of others. In this article, we study the conflict between commercial long-distance trains and subsidized commuter trains with a socio-economic perspective (i.e. travelers and train operators). The study attempts to answer the following question: What is the socio-economic effect of modifying the timetable of a commuter service?

    The case study treats the commuter train services in Stockholm. Trip data was collected from the local commuter train operator. An entropy maximization-based model was implemented to estimate the dynamic network Origin-Destination (OD) matrix. This dynamic matrix, of one full working day, was then used to estimate the number of travelers per train, and further converted for use in the microscopic simulation tool RailSys. Travel and waiting time are estimated for each OD pair and with that the generalized costs for the travelers and operators. The effect of crowding in the trains is included in the estimation. The article can be considered as an initiation to a novel method to calculate effects of changes in commuter train timetables. This novel approach enables to price commercial train slots in the capacity allocation process such as in an auction. It provides a new way to estimate the local train operator´s valuation of the different parameters (i.e. waiting, travel time and interchanges). Using RailSys for the estimation of times makes it possible to include capacity aspects that normally are difficult to reveal.

  • 6.
    Ait Ali, Abderrahman
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. Swedish National Road and Transport Research Institute (VTI), Sweden.
    Lindberg, Per Olov
    Swedish National Road and Transport Research Institute (VTI), Sweden.
    Eliasson, Jonas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Nilsson, Jan-Eric
    Swedish National Road and Transport Research Institute (VTI), Sweden.
    Peterson, Anders
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    A disaggregate bundle method for train timetabling problems2020Inngår i: Journal of Rail Transport Planning & Management, ISSN 2210-9706, E-ISSN 2210-9714, Vol. 16, artikkel-id 100200Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The train timetabling problem (TTP) consists of finding a feasible timetable for a number of trains which minimises some objective function, e.g., sum of running times or deviations from ideal departure times. One solution approach is to solve the dual problem of the TTP using so-called bundle methods. This paper presents a new bundle method that uses disaggregate data, as opposed to the standard bundle method which in a certain sense relies on aggregate data. We compare the disaggregate and aggregate methods on realistic train timetabling scenarios from the Iron Ore line in Northern Sweden. Numerical results indicate that the proposed disaggregate method reaches better solutions faster than the standard aggregate approach.

    Fulltekst (pdf)
    fulltext
  • 7.
    Ait Ali, Abderrahman
    et al.
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Odolinski, Kristofer
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Pålsson, Björn
    Mechanics and Maritime Sciences/CHARMEC, Chalmers.
    Torstensson, Peter
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Evaluating the mix of maintenance activities on railway crossings with respect to life-cycle costs2023Rapport (Annet vitenskapelig)
    Abstract [en]

    Switches & crossings (S&Cs) are vital assets as they allow for increased railway capacity by introducing flexibility and connectivity in railway networks. At the same time, this makes them critical since they can cause costly delays and disruptions if they are not well maintained. This motivates studies to improve maintenance strategies of S&Cs, considering both the life-cycle costs (LCC) of the assets and socio-economic transportation costs for passengers and freight customers. In this paper, the interdependence between deterioration mechanisms, maintenance activities, and expected LCC (including transportation costs) is investigated using a combination of mechanical and econometric modelling. The interrelation between the degradation of contact geometry and track settlement is analysed using simulations of dynamic vehicle–turnout interaction. Long-term mechanical degradation of the S&C is simulated for different maintenance strategies that correspond to different timing of the associated maintenance measures (crossing repair welding and tamping). This provides the basis for analysing the interdependence between preventive and corrective activities using econometric modelling. Based on a case study of a common type of S&Cs in the Swedish infrastructure, the impact of different maintenance strategies on LCC and transportation costs is analysed. Opportunities and challenges in the development of more socio-economically effective maintenance strategies of S&Cs are discussed.

    Fulltekst (pdf)
    FULLTEXT01
  • 8.
    Ait Ali, Abderrahman
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Peterson, Anders
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Värdering av trafikinformationsnyttor i tågtrafiken (VTT): slutrapport2024Rapport (Annet vitenskapelig)
    Abstract [sv]

    Tågförseningar tillsammans med ökande efterfrågan leder till betydande sociala kostnader. Ett sätt att minska dessa kostnader är genom effektiv kommunikation av olika typer av trafikinformation till passagerare. Beroende på vilken/när information tas emot minskar passagerarnas beteendeanpassningar deras resekostnader, särskilt vid förseningar.Detta projekt syftar till att beräkna de samhällsekonomiska nyttor som sådan trafikinformation ger. Detta åstadkoms genom att utveckla en kvantitativ modell för att kvantifiera värdet av att kommunicera information till resenärerna vid tågförseningar.Genom att studera olika störningsscenarier i ett studiefall från Stockholmspendeltåg, ger studien insikter till infrastrukturförvaltaren om samhällsnytta av sådana informationssystem som en del av de stora infrastrukturinvesteringarna. Dessa insikter kan också hjälpa till att utforma effektivare informationsstrategier för att minska samhällsekonomiska kostnader för tågstörningar. 

    Fulltekst (pdf)
    FULLTEXT01
  • 9.
    Ait Ali, Abderrahman
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten. VTI.
    Warg, Jennifer
    KTH Royal Institute of Technology, Stockholm, Sweden.
    Eliasson, Jonas
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Pricing commercial train path requests based on societal costs2020Inngår i: Transportation Research Part A: Policy and Practice, ISSN 0965-8564, E-ISSN 1879-2375, Vol. 132, s. 452-464Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    On deregulated railway markets, efficient capacity allocation is important. We study the case where commercial trains and publicly controlled traffic (“commuter trains”) use the same railway infrastructure and hence compete for capacity. We develop a method that can be used by an infrastructure manager trying to allocate capacity in a socially efficient way. The method calculates the loss of societal benefits incurred by changing the commuter train timetable to accommodate a commercial train path request, and based on this calculates a reservation price for the train path request. If the commercial operator’s willingness-to-pay for the train path exceeds the loss of societal benefits, its request is approved. The calculation of these benefits takes into account changes in commuter train passengers’ travel times, waiting times, transfers and crowding, and changes in operating costs for the commuter train operator(s). The method is implemented in a microscopic simulation program, which makes it possible to test the robustness and feasibility of timetable alternatives. We show that the method is possible to apply in practice by demonstrating it in a case study from Stockholm, illustrating the magnitudes of the resulting commercial train path prices. We conclude that marginal societal costs of railway capacity in Stockholm are considerably higher than the current track access charges.

    Fulltekst (pdf)
    fulltext
  • 10.
    Ait-Ali, Abderrahman
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem.
    Assessing the Use of Welfare-Based Track Access Charging for Railway Capacity Allocation2019Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The deregulation of railway markets has brought new challenges to the capacity allocation process. In this context, we present a new hybrid methodology for allocating railway capacity to commercial train operators. Commercial freight or passenger train operators compete with each other as well as with subsidised local commuter trains. In the method presented in this article, minimal track access charges are computed using a social cost-benefit analysis of alternative commuter train timetables. These minimal charges are used as a starting or reservation price in an auction-based method for capacity allocation between the commercial operators. The aim of this study is to assess the use of such a welfare-based track access charging system in a real case scenario. On a congested line in the region of Stockholm, we evaluate the welfare-based access charges of commercial operators. We show that the new methodology can be used to allocate capacity between subsidized and commercial train operators. Moreover, we provide an estimate of the marginal minimal access charge per train path that the commercial operators request.

  • 11.
    Hossein-Nia, Saeed
    et al.
    Department of Engineering Mechanics, Royal institute of technology (KTH), Sweden.
    Ait Ali, Abderrahman
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Odolinski, Kristofer
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Torstensson, Peter
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Stichel, Sebastian
    Department of Engineering Mechanics, Royal institute of technology (KTH), Stockholm, Sweden.
    Simulation-based evaluation of maintenance strategies using look-up tables2023Konferansepaper (Annet vitenskapelig)
  • 12.
    Nia, Saeed Hossein
    et al.
    Department of Engineering Mechanics, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Krishna, Visakh V.
    Department of Engineering Mechanics, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Odolinski, Kristofer
    Swedish National Road and Transport Research Institute (VTI), Stockholm, Sweden.
    Torstensson, Peter
    Swedish National Road and Transport Research Institute (VTI), Göteborg, Sweden.
    Ait Ali, Abderrahman
    Swedish National Road and Transport Research Institute (VTI), Stockholm, Sweden.
    Sundholm, Lars
    Swedish Transport Administration, Luleå, Sweden.
    Larsson Kråik, Per-Olof
    Swedish Transport Administration, Luleå, Sweden.
    Stichel, Sebastian
    Department of Engineering Mechanics, Royal Institute of Technology (KTH), Stockholm, Sweden.
    Simulation-based evaluation of maintenance strategies from a life cycle cost perspective2023Inngår i: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 532-533, s. 258-265, artikkel-id 205120Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A methodology that combines simulations of long-term mechanical degradation including maintenance interventions with an assessment of the associated socio-economic impact is proposed. This development responds to an urgent need within the railway sector to enable the evaluation of maintenance strategies from a LCC perspective. The functionality of the methodology is demonstrated in an investigation of rail grinding strategies for a curve on the Swedish Iron-ore line. The results indicate a reduction in LCC of 20% when using a harder rail material (R400HT) combined with annual rail grinding as compared to a softer rail material (R350LHT) and two grinding campaigns per year.

    Fulltekst (pdf)
    FULLTEXT01
  • 13.
    Odolinski, Kristofer
    et al.
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Nilsson, Jan-Eric
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Sjöstrand, Henrik
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Ait Ali, Abderrahman
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Lidén, Tomas
    Statens väg- och transportforskningsinstitut, Trafikanalys och logistik, TAL.
    Att följa upp och utvärdera järnvägsunderhåll: Delrapport inom projektet Metod för jämförelsestudier av järnvägsunderhåll2023Rapport (Annet vitenskapelig)
    Abstract [sv]

    Med start 2025 avser Trafikverket förändra formerna för upphandling av basunderhåll i tre geografiska områden. Förändringarna innebär att en större mängd planering och produktionsledning sker i Trafikverkets regi. Syftet är att utveckla den egna beställarförmågan och att stärka leverantörsmarknaden.

    VTI har fått Trafikverkets uppdrag att föreslå metoder för att kunna följa upp konsekvenserna av den förändrade organisationen. I rapporten redovisas uppdragets första del med fokus på konsekvenserna av ett förändrat ansvar för basunderhåll av Södra Malmbanan. Syftet med delstudien är att identifiera den information som krävs och de metoder som kommer att användas för att fördjupa förståelsen av hur den nya ansvarsfördelningen förändrar kostnader och förutsättningarna för trafik jämfört med dagens förfarande. Förutom att skapa goda förutsättningar att utvärdera de förändringar som genomförs kommer detta arbete också att kunna ge stöd för övergången till nya verksamhetsupplägg i de ytterligare två områden som står på tur att förändras, Ostkustbanan (2026) och Mälarbanan (2027). Information har inhämtats från personal inom Trafikverket och från aktörer på leverantörsmarknaden, samt via analyser av dokumentationen av underhållsverksamheten liksom en genomgång av relevant litteratur.

    De betydande förändringar av verksamheten som förestår kan få konsekvenser i flera avseenden. För att kunna följa upp och jämföra kostnader och andra utfall i hela landet krävs uppgifter från samtliga kontraktsområden med avseende på verksamhetens kostnader, omfattning (antal kilometer bana, installationer av växlar och konstbyggnader), trafik, väder etcetera. Tack vare att Trafikverket sedan länge byggt upp databaser som innehåller den aktuella informationen är en viktig del av det fortsatta arbetet att etablera ett smidigt tillvägagångssätt för att årligen kunna komplettera informationen och göra nya observationer av förändringar som kan ha inträffat. Ett antal frågeställningar föreslås som kan besvaras med stöd av en analys av det föreslagna materialet. Svaret på dessa frågor gör det möjligt att stärka förståelsen av den verksamhet som bedrivs och att ta fram kunskap som kan omsättas i praktiken.

    Fulltekst (pdf)
    FULLTEXT01
  • 14.
    Odolinski, Kristofer
    et al.
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Nissen, Arne
    Trafikverket.
    Ait Ali, Abderrahman
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Finding a better renewal time and improved contract design for switches and crossings2023Rapport (Annet vitenskapelig)
    Abstract [en]

    Switches and crossings are critical assets in railway systems and their maintenance and renewal costs can be substantial. This paper evaluates the economic impact of cumulative loads on such assets and the effect of different contract designs for railway maintenance. Results from survival analyses are combined with a life cycle costing model to analyse costs for maintenance, train delays, and renewals. The findings provide insights into improving the timing of asset renewal as well as the impact of different reimbursement rules in the design of maintenance contracts. The estimated optimal lifetimes of different types of switches and crossings are similar to their technical lifetimes, yet there a couple of exceptions. The estimated effects of the reimbursement rule provide unique results on the risk premiums allowed in order to achieve a break-even between different maintenance contract designs.

    Fulltekst (pdf)
    FULLTEXT01
  • 15.
    Torstensson, Peter
    et al.
    Statens väg- och transportforskningsinstitut, Miljö, MILJÖ.
    Hossein-Nia, Saeed
    Vehicle Engineering and Technical Acoustics, School of Engineering Sciences, KTH Royal Institute of Technology, Stockholm, Sweden.
    Ait Ali, Abderrahman
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Odolinski, Kristofer
    Statens väg- och transportforskningsinstitut, Transportekonomi, TEK.
    Larsson Kråik, Per-Olof
    Trafikverket, Luleå, Sverige.
    Krishna, Visakh
    School of Engineering Sciences, KTH Royal Institute of Technology, Stockholm, Sweden.
    Sundholm, Lars
    Trafikverket, Luleå, Sverige.
    LCC evaluation of rail maintenance strategies using simulations of long-term mechanical degradation2024Inngår i: Sammanställning av referat från Transportforum 2024 / [ed] Fredrik Hellman; Mattias Haraldsson, Linköping: Statens väg- och transportforskningsinstitut , 2024, s. 408-409Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Rail infrastructure is an important part of transport systems, improving accessibility and contributing to economic growth. This requires costly maintenance and renewal activities that are subject to budget constraints. There is a need to carry out the right activity at the right time to make best use of limited resources. This paper proposes a methodology to evaluate the performance of different rail grinding strategies from a life cycle cost (LCC) perspective. The procedure is innovative in such a way that it uses simulations of long-term mechanical degradation with respect to different maintenance interventions and combines these simulations with an assessment of the associated economic impact. The utilisation of mechanical modelling makes the procedure able to analyse new/innovative maintenance strategies or changes in infrastructure/vehicle design, as well as to perform optimisation and parameter studies under controlled conditions.   

    The proposed methodology for LCC evaluation is applied to compare the performance of different maintenance strategies on a 495 m radius curve on the Iron-ore line in Sweden. The traffic consists of freight trains containing two back-to-back connected three-axle locomotives and 67 wagons on three-piece bogies. The annual traffic volume is around 37 mega gross tonnes (MGT) corresponding to around 20 train passages each day, half (un)loaded, with 30 tonnes axle load. 

    Three different maintenance strategies are investigated; (S1) the currently applied strategy on the Iron-ore line corresponding to rail grinding performed biannually on rail material R350LHT, (S2) rail grinding performed annually on rail material R400HT, and (S3) the same as (S1) but with gauge width correction performed to prevent it from exceeding 1450 mm.  

    Long-term rail profile evaluation due to mechanical degradation and rail grinding is assessed by iterative simulations of dynamic vehicle–track interaction in the software GENSYS. Rail damage due to wear and rolling contact fatigue are modelled in accordance with Archard’s theory and the method by KTH, respectively.  

  • 16.
    Warg, Jennifer
    et al.
    Royal Institute of Technology, Sweden.
    Ait Ali, Abderrahman
    Royal Institute of Technology, Sweden.
    Eliasson, Jonas
    Stockholm City Transportation Administration, Sweden.
    Assessment of Commuter Train Timetables Including Transfers2019Inngår i: Special Issue: 21st EURO Working Group on Transportation Meeting, EWGT 2018, 17th – 19th September 2018, Braunschweig, Germany / [ed] Bernhard Friedrich, Dirk C. Mattfeld, Anysia Mayerhofer, Bruno Albert Neumann Saavedra, 2019, Vol. 37, s. 11-18Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Many railway networks suffer from high capacity utilisation. For scheduling all services, adjustments to the desired slots are often needed. Such adjustments might lead to longer travel times, crowded trains, longer waiting times for boarding and for transfers. All of this has an important socio-economic impact on both travellers and train operators. This raises the question of the socio-economic assessment of changes in commuter train timetables including transfers. Thus, the aim of this study is to evaluate the effects of adjustments of commuter train timetables on the traveller (i.e. consumer costs) and the train operator (i.e. producer costs). These costs are estimated based on all train trips and operations in the network. In a case study, the effect of changes in departure times (resulting in non-regular interval timetables) is analysed. Further, the price of cancelling a two-way service during different times of the day is compared. The results show that changing departure times can both decrease and increase the total costs, and that regularity for parallel services might not be as important as expected if it is kept for each separate service. For the second study, waiting times for transfers were indicated to have a (too) large impact which can lead to misleading results and might be adjusted in future work. The model is adequate for such kind of questions but needs some more adjustments. For railway networks with dense and heterogeneous traffic (as is the case in Sweden), the contributions of this model are useful for making the challenging timetabling process easier and commuter train services less costly.

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