Change search
Refine search result
1 - 13 of 13
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Folkesson, Anders
    et al.
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Lindfeldt, Anders
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology, Energy Processes.
    Saxe, Maria
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Alvfors, Per
    KTH, School of Chemical Science and Engineering (CHE), Chemical Engineering and Technology.
    Study of the fuel economy improvement potential of fuel cell buses by vehicle simulationArticle in journal (Other academic)
  • 2.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    A study of the performance and utilization of the Swedish railway network2010In: Road and Rail Infrastructure / [ed] Stjepan Lakušić, University of Zagreb , 2010Conference paper (Refereed)
    Abstract [en]

    Many lines in the Swedish railway network are heavily utilized and the demand forfreight transport and passenger traffic is increasing. The Swedish National RailAdministration has been forced to declare some sections to be overloaded andwith the up-coming deregulation of railway traffic, the load is going to increaseeven more.This paper describes how the performance of the entire Swedish railway networkhas been investigated and the results. Data from several different databases(supplied by the Swedish Railway Administration) has been processed. The dataconsists of the scheduled timetable, data about the design of the infrastructureand operational data such as recorded delays, train weights and train lengths.To perform the calculations, the railway network has been divided into 123sections. The division has been made according to traffic patterns and type ofinfrastructure (single-track, double-track). For each line, the data has been usedto calculate several descriptive parameters, e.g. delay development, number oftrains/h during different parts of the day, time for the peak hour, inter-stationdistance, track length, train length, train weight, total mass/day (freight trains),train average speed and the heterogeneity of the train speeds.Together, all of the parameters form a picture of the traffic flows in the Swedishrailway grid and identifies the characteristics of the different lines such as: load,traffic mix, delay situation and infrastructure performance. The information can beused to detect deficiencies and propose possible solutions.Finally, the correlation between the calculated parameters and the delay situationhas been investigated.

  • 3.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Congested railways: influence of infrastructure and timetable properties on delay propagation2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis the symptoms and underlying behaviour of congestion on railways are analysed and discussed. As well as in many other countries, Sweden faces increasing demand for transport. To meet this new demand, railways play an important role. Today, the capacity of the Swedish rail network is not upgraded at the speed necessary to keep up with the increase in traffic demand. The sensitivity of the railway system rises as the capacity utilisation increases. At some point the marginal gain of operating one extra train is lower than the costs in term of increased sensitivity to delay, i.e. maximum capacity has been reached.

    Two methodologies are employed in this thesis to analyse capacity. The first uses real data from the Swedish rail network, train operation and delays to analyse how different factors influence available capacity and delay creation. Several useful key performance indicators are defined to describe capacity influencing properties of the infrastructure and the rail traffic. The rail network is divided into subsections for which the indicators have been estimated. This makes it possible to discern their different characteristics and identify potential weaknesses.

     The second approach employs the railway simulation tool RailSys in extensive simulation experiments. This methodology is used to analyse the characteristics of double track operation. Simulation of several hundred scenarios are conducted to analyse the influence of traffic density, timetable speed heterogeneity, primary delays and inter-station distance on secondary delays and used timetable allowance. The analysis gives an in-depth understanding of the mechanisms behind the performance of a double track.

  • 4.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Heterogeneity Measures and Secondary Delays on a Simulated Double-Track2013In: Proceedings of the 5th International Seminar on Railway Operations Modelling and Analysis, Copenhagen, Denmark, 2013, 2013Conference paper (Refereed)
    Abstract [en]

    The demand for transportation on railways grows for each year and many railway lines are already used close to maximum capacity. One way to increase capacity is to reduce traffic heterogeneity. Heterogeneity is introduced when train services with different speeds operate on the same line. There are many definitions of heterogeneity in literature. Good measures are important in order to be able to quantify capacity lost due to heterogeneity, and consequently how capacity can be gained by reducing it. This paper analyse some of the existing measures as well as introduces a new one, Mean Pass Coefficient (MPC). Other measures analysed are: number of speed levels (SL), speed ratio of fastest to slowest train (SR), mean difference in free running time (MDFR) as well as sum of shortest headway reciprocals (SSHR) and sum of arrival headway reciprocals (SAHR).

    Two infrastructure models of double-track lines with overtaking stations spaced at different intervals are simulated. A large number of timetables are created where traffic density as well as the mix of slower and faster trains is varied. Each timetable is characterized using the different definitions of heterogeneity and the results are used in regression analyses to determine their explanatory value with respect to secondary delays created in the simulations. Results show that MPC performs best closely followed by MDFR and SR, while SL is worse when it comes to explaining secondary delays. SSHR and SAHR also show good performance. The performance of the measures increases when primary delays are high, but is unaffected by interstation distance.

  • 5.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Investigating The Impact Of Timetable Properties On Delay Propagation On A Double-Track Line Using Extensive Simulation2011Conference paper (Refereed)
    Abstract [en]

    Today many railway lines are operated close to maximum capacity. A common question asked is: “How is the quality of operation affected if one additional train/h is scheduled?” With the upcoming deregulation of operation, the necessity to be able to answer this question accurately increases when service operators that are denied train slots due to congestion demand a motivation.

    The objective of this paper is to investigate how secondary delays on a congested double-track line depend on several parameters such as:

    • Number of trains/h.

    • Timetable heterogeneity (speed difference).

    • Primary delay levels.

    • Inter-station distance.

    Each combination of settings of the parameters is investigated to capture possible interaction effects.

    The infrastructure model consists of a fictitious double-track line with overtaking stations at regular intervals. A program that generates timetables and perturbation data according to specified input settings is developed. The output of the program is data files that can be read directly by the well-known simulation tool RailSys. This process makes it possible to simulate the hundreds of different timetables that are the result when the parameters investigated are varied. The outcome of the simulations is analysed to find the influence of the investigated parameters on the secondary delays.

  • 6.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport and Economics (closed 20110301), Traffic and Logistics (closed 20110301). KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Kapacitetsanalys av järnvägsnätet i Sverige: Delrapport 2, Bearbetning av databas över infrastruktur, trafik, tidtabell och förseningar2009Report (Other academic)
  • 7.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Kapacitetsutnyttjande i det svenska järnvägsnätet: Uppdatering och analys av utvecklingen 2008 – 20122014Report (Other academic)
    Abstract [sv]

    Detta projekt är en uppföljning till projektet ”Kapacitetsanalys av järnvägsnätet i Sverige – Bearbetning av databas över infrastruktur, trafik, tidtabell och förseningar” som utfördes vid KTH under 2008-2009 på uppdrag av dåvarande Banverket. Syftet är att uppdatera de nyckeltal som beräknades 2008 utifrån 2012 års situation och utreda vad som hänt sedan dess.

     

    Flera av Trafikverkets databaser har använts för att göra en beskrivning av Sveriges järnvägsnät. Beskrivningen utgörs av flertalet nyckeltal som omfattar information om infrastruktur, tidtabell, trafik och förseningar. Järnvägsnätet har delats in i mindre stråk som nyckeltalen beräknats för. Resultaten presenteras framförallt i form av kartor som gör det möjligt att snabbt skaffa sig en nationell överblick av situationen 2012 och ev. förändring sedan 2008.

     

    De databaser som använts för att göra beräkningarna är BIS, Tidtabellsboken och Lupp. Några av de nyckeltal som beräknats är: stationsavstånd, spårlängd på stationerna, andel stationer med samtidig infart, antal tåg per dag, tidpunkt för maxtimmen, antal tåg under maxtimmen, tågens hastighet, tågens blandning med avseende på hastighet, godstågens längd/vikt/axellast, andel långa persontåg, bruttoton/dag, andel merförsenade tåg, och medianen av merförseningen per 100 km hos de på sträckan merförsenade tågen. Nya nyckeltal som tagits fram och som ej beräknades 2008 är: andelen tåg som reducerat sin försening och medianen på reduktionen per 100 km hos dessa tåg, andelen godståg som är längre än medelspårlängden av stationerna på sträckan, utnyttjad kapacitet och antal framförda tåg jämfört med vad som planterats.

     

    Resultaten sammanfattas på nationell nivå för de viktigaste nyckeltalen. Alla nyckeltal redovisas i ett Excellark (separat fil, ingår ej i rapporten). Dessutom har arbete lagts ned på att granska kvaliteten på förseningsdata från Lupp som använts i projektet.

  • 8.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Railway capacity analysis: Methods for simulation and evaluation of timetables, delays and infrastructure2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In this thesis the symptoms and underlying behaviour of congestion on railways are analysed and discussed. As well as in many other countries, Sweden faces increasing demand for transportation. To meet this new demand, railways play an important role. Today, the capacity of the Swedish rail network is not upgraded at the pace necessary to keep up with the increase in traffic demand. The sensitivity of the railway system rises as the capacity utilisation increases. At some point maximum capacity is reached when the marginal gain of operating one extra train is lower than the costs in terms of longer travel times and increased sensitivity to delays.

    Several different methodologies are employed in this thesis to analyse capacity. The first uses real data from the Swedish rail network, train operation and delays to analyse how different factors influence available capacity and train delays. Several useful key performance indicators are defined to describe capacity influencing properties of the infrastructure and the rail traffic. The rail network is divided into subsections for which the indicators have been estimated. This makes it possible to discern their different characteristics and identify potential weaknesses.

    The second approach employs the railway simulation tool RailSys in extensive simulation experiments. This methodology is used to analyse the characteristics of double-track operation. Simulation of several hundred scenarios are conducted to analyse the influence of traffic density, traffic heterogeneity, primary delays and inter-station distance on secondary delays, used timetable allowance and capacity. The analysis gives an in-depth understanding of the mechanisms of railway operation on double-track lines.

    A simulation model for strategic capacity evaluation, TigerSim, is developed that can be used to speed up and improve capacity planning and evaluation of future infrastructure and timetables designs on double-track railway lines. For a given infrastructure and plan of operation, the model can be used to generate and simulate a larger number of timetables. This gives two major advantages:

    • Using many timetables makes results general
    • It is possible to consider both static and dynamic properties of the timetables in the capacity analysis

    The first aspect is especially useful in the evaluation of future scenarios as the timetable then often is unknown. The second is an advantage since an improvement in capacity can be measured in a combination of increased frequency of service, shorter travel time and reduced delays. The output of the model can either be used to directly determine capacity from a quality of service perspective, or used as input to cost-benefit analysis (CBA).

  • 9.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Scheduled waiting time and delay in capacity evaluation of double-track railway linesManuscript (preprint) (Other academic)
  • 10.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Validation of a simulation model for capacity evaluation of double-track railway lines2015In: Proceedings of the 6th International Seminar on Railway Operations Modelling and Analysis (RailTokyo2015), Tokyo, Japan, 2015Conference paper (Refereed)
    Abstract [en]

    Capacity is partially a matter of quality versus quantity. Increasing capacity utilization gives more scheduled waiting time in the timetable as well as more delays when trains are operated. A common way to analyse capacity is to first make a timetable and then use it in a simulation where trains are perturbed. This way it is possible to establish the scheduled waiting time and the expected delays of the trains at the same time as market demands on traffic, e.g. frequency of different train services, are considered. However, setting up simulations are often time consuming and requires a lot of input data.

    A method is developed with the objective to improve and speed up capacity analysis of double track railway lines. It can be used for both timetable generation and timetable simulation. The focus of this paper is to present the model and validate that it can simulate timetables accurately. The model has a macroscopic representation of the railway infrastructure and rolling stock while timetables and perturbations are modelled in more detail. When resolving conflicts, the dispatching algorithm can consider several trains and take into account how the dispatching decision affects the possibility to make good decisions at the next station.

    The validation is performed using the micro simulation tool RailSys as reference. The validation covers a wide range of scenarios of different traffic density, timetable heterogeneity, inter station distance and primary delays. The validation shows good results and the conclusion is that despite the simplicity of the model, it is accurate enough to use in capacity analysis.

  • 11.
    Lindfeldt, Anders
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Sipilä, Hans
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport Planning, Economics and Engineering.
    Användning av tågpassagedata för estimering av primära störningsfördelningar2016Report (Other academic)
    Abstract [sv]

    Syftet med detta PM är att presentera metoder för estimering av primära linje- och uppehållsfördelningar (störningar) för användning i simulering. Metoderna bygger på användning av Trafikverkets tågpassagedata.

  • 12.
    Lindfeldt, Anders
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Sipilä, Hans
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Simulation of freight train operations with departures ahead of schedule2014In: Comprail 2012, WIT Press, 2014Conference paper (Refereed)
    Abstract [en]

    Many lines in Sweden have mixed traffic, with both passenger and freight trains. In contrast to passenger trains, freight trains can deviate significantly from their timetable. This study evaluates the effect of modelling freight trains running ahead as well as behind schedule. In previous Swedish studies freight trains have been modelled as being on time or delayed. RailSys is used to simulate a section of the Southern Main Line and a fictive double-track line. Simulation results are compared to data from real train operation. Results show that freight trains can be modelled in a more realistic way. This can improve simulation analysis of freight operations.

  • 13.
    Nelldal, Bo-Lennart
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Lindfeldt, Anders
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Lindfeldt, Olov
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics.
    Kapacitetsanalys av järnvägsnätet i Sverige: Delrapport 1, Hur många tåg kan man köra? En analys av teoretisk och praktisk kapacitet2009Report (Other academic)
    Abstract [sv]

    Järnvägsgruppen vid Kungliga Tekniska Högskolan (KTH) i Stockholm bedriver tvärvetenskaplig forskning och utbildning inom järnvägsteknik och tågtrafikplanering. Syftet med forskningen är att utveckla metoder och bidra med kunskap som kan utveckla järnvägen som transportmedel och göra tåget mer attraktivt för transportkunderna och mer lönsamt för järnvägsföretagen. Järnvägsgruppen finansieras bland annat av Trafikverket, Bombardier och Branschföreningen Tågoperatörerna.

    Detta projekt ”Kapacitetsanalys av det svenska järnvägsnätet” har finansierats av Banverket och redovisas i tre delrapporter:

    1. Hur många tåg kan man köra? En analys av teoretisk och praktisk kapacitet

    2. Bearbetning och analys av databas över infrastruktur, trafik, tidtabell och förseningar

    3. Förslag till åtgärder för att öka kapaciteten på kort sikt.

    Andra intressanta rapporter från Järnvägsgruppen vid trafik och logistik finns på vår hemsida www.infra.kth.se/tol/jvg

1 - 13 of 13
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf