| 1. |
- Hellblom, Elin, et al.
(författare)
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Metodutveckling för beräkning av kapacitetsutnyttjande på stationer
- 2024
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Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 108-109
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- För att tillhandahålla och upprätthålla robust och relevant järnvägstrafik är god tidtabellsplanering och kapacitetsanalys väsentligt. Riktlinjerna från UIC 406 och kompressionsmetoden är en av de mest använda metoderna för kapacitetsberäkningar, framför allt för linjer, men har i den andra upplagan även kompletterats med ett tillägg för beräkning av kapacitet i noder och stationer. I metoden delas beräkningar för stationsområdet upp i växel- och spåravsnitt, och därför finns utrymme till förbättringar för att utveckla metoder där växel- och spårområde är integrerade. Trafikverket använder en variant som bygger på kompressionsmetoden från UIC 406, men den används mest för linjer och har svårt att fånga upp vissa åtgärder i systemet, t.ex. stationer. Weik et al. introducerar ett Matlab-baserat simuleringsverktyg för tidtabellsoberoende komprimering i stationsområden där stationerna behandlas i sin helhet istället för att separeras i spår- och växelområden. Den föreslagna metoden är baserad på UIC 406-metoden där analysen utförs på en mikronivå med blocksträckor och blockeringstid för att bättre fånga upp beroenden inom stationsområdet. Modellen använder sig av infrastruktur och tidtabellsdata importerad från Trafikverkets RailSys-modell och går igenom konflikter mellan tåg som delar samma blocksträcka. Komprimeringen görs för en given tidsram. En Monte Carlo-simulering används för att skapa en fördelningsanalys.För att utöka den tidigare metoden har ett tillägg som hanterar vändande tåg och alternativa tågvägar formulerats. Syftet med detta arbete är att jämföra effekten av att koppla vändande tåg och/eller alternativa spår med kapacitetsberäkningsmodellen. Analysen genomförs som en fallstudie av två stationer och två tidtabeller.De preliminära resultaten visar att det finns en påverkan på kapacitetsutnyttjandet på stationen när kompressionen görs med sammankopplade vändande tåg där ankommande + avgående tåg räknas som ett gemensamt tågsätt. På grund av minskningen av möjliga tidtabellssammansättningar i randomiseringen och att variationen blir mindre flexibel kan också en förändrad fördelning av kapacitetsutnyttjande från Monte Carlosimuleringen urskiljas. Resultatet för analys med alternativa tågvägar visar en minskad kapacitetsförbrukning. Om ett spår är upptaget i den tidigare metoden kommer det andra tåget att behöva vänta, men i den nya metoden kan det använda ett annat spår och därmed återspegla en aktiv tågklarerare.
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| 2. |
- Johansson, Ingrid, 1990-, et al.
(författare)
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Rail platform allocation for reliable interchanges
- 2024
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Ingår i: Transportation Research Procedia. - : Elsevier BV. - 2352-1465. ; 78, s. 198-205, s. 198-205
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Tidskriftsartikel (refereegranskat)abstract
- Changing trains is a crucial part of many rail journeys, and it is important that arrival and departing trains are allocated close to each other for a swift interchange. Today the platform allocation of trains is often based on local traditions, where trains of the same type to the same destination depart from the same track. In this paper we address the problem of using the platform tracks in the best way, balancing crossing train paths with easy interchanges at the same platform. We use a RailSys model of the station in Norrköping, Sweden, to assess three platform allocation strategies with respect to crossing train paths and train changes at the same platform. Moreover, the capacity utilisation is calculated by a timetable compression-based method. The results show that a platform allocation maximising the changes at the same platform leads to more crossing train paths and higher capacity utilisation. Future work includes more accurate modelling of train connections, assessment of delays through simulation, and a cost-benefit analysis to find the best balance between easy interchanges and conflicting train paths.
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| 3. |
- Johansson, Ingrid, et al.
(författare)
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Vilket tåg från vilket spår? : En balansakt mellan snabba byten, enkel tågklarering och effektivt kapacitetsutnyttjande
- 2024
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Ingår i: Sammanställning av referat från Transportforum 2024. - Linköping : Statens väg- och transportforskningsinstitut. ; , s. 112-113
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Changing trains is a crucial part of many rail journeys. It is essential for reaching all destinations, but it takes time and is often stressful, especially when the arriving train is delayed. In models for cost-benefit analyses, interchange time for the railway is typically considered 2-3 times more expensive than in-vehicle time. Designing and operating railway stations in a way that could minimise the required interchange time is therefore vital for making rail travel attractive. This study addresses the problem of using the platform tracks in the best way, balancing crossing train paths with easy interchanges across the same platform. Primarily, we look at the problem on a tactical level, i.e., timetable planning, but the insights are also useful on a strategic level for designing and re-designing railway stations, and on an operational level, doing the dispatching. This study explores principal differences when prioritising a few crossing train paths versus fast interchanges, using simple, ideal principles for allocating trains to platform tracks in RailSys. These principles are using the track allocation from a given timetable, using the lowest numbered track that is free, and maximising train changes at the same platform. The analysis is performed for Norrköping station using the timetable of a normal Thursday in autumn 2021 and counting the number of possible connections between trains, here defined as a minimum of 5 and a maximum of 30 minutes between the arrival time of a train and the departure time of another train. To investigate the effects of the track allocation principles, the number of connections at the same platform and the number of connections with crossing train paths, i.e. to some extent use the same station infrastructure, have been counted. 205 passenger trains with 1,033 possible connections were identified. Results show that capacity utilisation and the number of crossing train paths increase when the number of connections from the same platform is increased. Increasing the number of connections from the same platform increases crossing train paths and capacity utilisation.
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| 4. |
- Jansson, Emil
(författare)
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Challenges with Driverless and Unattended Train Operations
- 2023
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Demand for transportation continues to increase, for both freight and passenger services. One of the most energy-efficient modes of transportation is rail. One solution to increase the attractiveness of rail transport is to introduce automatic train operation (ATO) with a high grade of automation (GoA). Driverless and unattended train operation could entail positive effects but would also bring challenges when removing the train driver. Thus, there is a need to understand the role of train drivers, especially in unplanned events. The main research objectiveis to understand the train driver roles during unplanned events and the frequency of such events. This thesis includes three papers to fulfill the research objective.This thesis studied delay logs and trackside sensor logs. A qualitative method, thematic analysis, was used to identify themes of the roles performed by train driver from the delay logs. The chi-square test statistical method was used to analyze these trackside sensor logs.Six main categories of tasks for train drivers were identified for unplanned events. Detect, Report, Inspect, Adjust, Manage passengers, and Respond to train orders. Each category was analyzed for each grade of automation by giving the responsibility for each category. The results highlight in a novel way the varied challenges between grade of automation in mainline systems. Detecting abnormalities was the most common task train drivers performed during unplanned events. Train drivers use four human senses to detect abnormalities: sight, hearing, touch, and smell. This indicates the need for onboard sensors. However, the real challenge is in processing all sensor data to gain anaccurate evaluation of any fault. One specific type of unplanned event in which the train driver is needed involves trackside sensor alarms. Freight trains are ten times more likely to trip an alarm than passenger trains. Alarms are more frequent in colder climate zones during winter months. These differences are statistically significant and indicate that not all lines and train types might be suitable for a high grade of automation.If driverless or unattended train operation will become a reality in future, many challenges must be met. This thesis gives deeper understanding of these challenges using a novel way to identify and quantify train driver tasks during unplanned events.
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| 5. |
- Johansson Mignon, Ingrid, 1983, et al.
(författare)
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Sustainable business models and innovation strategies to realize them: A review of 87 empirical cases
- 2023
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Ingår i: Business Strategy and the Environment. - : Wiley. - 1099-0836 .- 0964-4733. ; 32:4, s. 1357-1372
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Tidskriftsartikel (refereegranskat)abstract
- The importance of developing sustainable business models has recently received increased interest in society and among scholars. While firms attempt to innovate their business models towards sustainability or create new businesses to address sustainability issues, it becomes clear that there is no one-size-fits-all model when it comes to sustainable business models. Consequently, firms often struggle to identify, develop, and implement sustainable business models that suit them. This paper aims to address this problem by drawing on the wealth of recently published empirical studies and reviewing 87 cases where firms have performed business model innovation to achieve sustainable business models. Four main sustainable business models are identified that have been achieved through different business model innovation strategies. The review contributes to managers by offering a portfolio of strategies to achieve sustainable business models and to research by clarifying the relation between the business model innovation and sustainable business model concepts.
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| 6. |
- Johansson Mignon, Ingrid, 1983, et al.
(författare)
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The role of public energy advising in sustainability transitions– empirical evidence from Sweden
- 2023
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Ingår i: Energy Policy. - : Elsevier BV. - 0301-4215. ; 177
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Tidskriftsartikel (refereegranskat)abstract
- Public energy advising is a policy measure used to provide customized energy information and advice to energy end-users. It aims at encouraging and promoting decisions leading to reduced environmental impact from energy use. While the independent function of public energy advising is unique and important, in Sweden, the role of energy advisors is changing. With new and more complex client demands as well as increasing competition from other forms of advising, there is a need to examine the shift that public energy advising is facing. The aim is to provide an overview of the activities performed by public energy advisors in Sweden and to explore the roles that they play in the transition to a sustainable energy system. Based on a qualitative analysis of 129 activity reports from Swedish municipal energy advisors, this paper shows that public energy advisors do not only play a role on an actor-level, but also on a system-level, by undertaking activities connecting the target groups to other actors in society and translating national policy to the local level. These system-level roles represent an important potential for policies aimed at accelerating the energy transition, and thus they should be encouraged and maximized.
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| 7. |
- Palmqvist, Carl William, et al.
(författare)
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A method to separate primary and secondary train delays in past and future timetables using macroscopic simulation
- 2023
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Ingår i: Transportation Research Interdisciplinary Perspectives. - : Elsevier. - 2590-1982. ; 17, s. 100747-100747
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Tidskriftsartikel (refereegranskat)abstract
- Punctuality is a key factor in railway operations and is affected by both primary and secondary delays to differing degrees. Being able to separate these two types of delays is very important when simulating operations, and when conducting punctuality improvement efforts. However, it is not easy to estimate the relative proportions of primary versus secondary delays using historical data. In this paper, we demonstrate a method that uses repeated runs of a macroscopic simulation tool to estimate what share of delays has been primary or secondary. Using the Swedish region of Skåne as a case study, we estimate that about 36% of delays in 2019 were primary, leaving 64% as secondary. We further show that in order for operations to reach the targeted level of punctuality, 95% instead of the observed 87%, primary delays would have had to be cut by half. Using a draft timetable for 2025, we also simulate what the punctuality would be given different assumptions of primary delays. Assuming the same level of primary delays in 2025 as in 2019, we estimate that the punctuality would drop by a further 5 percentage points due to increased density of operations. In order to reach the punctuality target of 95% in 2025, primary delays would instead need to be reduced by two-thirds. At the request of the infrastructure manager, we also show the predicted geographical distribution of secondary delays in this future timetable. Our results highlight the need for drastic delay reduction measures to reach set targets.
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| 8. |
- Bankel, Amanda, 1992, et al.
(författare)
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Solar business models from a firm perspective – an empirical study of the Swedish market
- 2022
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Ingår i: Energy Policy. - : Elsevier BV. - 0301-4215. ; 166
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Tidskriftsartikel (refereegranskat)abstract
- A worldwide transition towards sustainable energy systems requires the diffusion of renewable electricity technologies. To achieve this, recent research has put emphasis on the role of business models as catalysts for sustainability transitions, particularly in the case of solar photovoltaics. Authors have identified a variety of solar business models that can be characterized based on roles, activities, and applications. In contrast, on the market, solar firms use business models to communicate their offer to clients, focusing on customers’ needs, how they organize their resources and activities to meet these needs and, in return, create value for themselves. The aim of this paper is to bridge the gap between the way the energy policy literature describes solar business models, and the way solar firms use them to communicate with their clients. The business models of 241 solar firms in Sweden were mapped and analyzed using a framework developed by Richardson (2008) as well as the roles, activities, and applications highlighted in solar business model literature. This led us to identify six types of solar business models. We found that there are some gaps and overlaps between theoretical and empirical solar business models which, in turn, have implications for theory and policy.
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| 9. |
- Johansson, Ingrid, 1990-, et al.
(författare)
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Microscopic and macroscopic simulation of early freight train departures
- 2022
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Ingår i: Journal of Rail Transport Planning & Management. - : Elsevier BV. - 2210-9706 .- 2210-9714. ; 21
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Tidskriftsartikel (refereegranskat)abstract
- In Sweden and other countries it is not an uncommon practice that freight trains depart more or less on-demand instead of strictly following a pre-planned timetable. However, the systematic effects of freight trains departing late or (in particular) early has long been a contested issue. Although some microscopic simulation tools currently have the capability to evaluate the effect of freight trains departing before schedule, it has yet not been established how macroscopic simulation tools, capable of fast simulation of nation-wide networks, can manage such tasks. This paper uses a case study on a line between two large freight yards in Sweden to investigate how the results of microscopic and macroscopic simulation, represented by two modern simulation tools, differ when it comes to this particular problem. The main findings are that both the microscopic and the macroscopic tools replicated the empirical punctuality fairly well. Furthermore, allowing early departures of freight trains increased overall freight train punctuality while the passenger train punctuality decreased slightly, as determined by both tools. The results are encouraging, but further studies are needed to determine if macroscopic simulation is on-par with microscopic simulation.
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| 10. |
- Johansson, Ingrid, 1990-, et al.
(författare)
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Simulating the Punctuality Impacts of Early Freight Train Departures
- 2022
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Ingår i: Proceedings of The 13th World Congress on Railway Research (WCRR). ; , s. 1-6
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Konferensbidrag (refereegranskat)abstract
- Railway traffic usually adheres to a timetable, but in Sweden, around two-thirds of the freight trains depart before they are scheduled, often by hours. Even though they occur in real operations, early departures have rarely been included in simulation studies and the effects on punctuality are not fully investigated. With a macroscopic simulation tool such as PROTON, large networks can be simulated in a short time, which makes the simulation process easier. This paper uses the tool PROTON to perform a macroscopic simulation case study on the Swedish Western mainline to investigate how early departures of freight trains affect punctuality. The resulting output is a marginal overall punctuality improvement of about +0.5 percentage points. In addition, different levels of primary run time and dwell time delays have been used as simulation input, based on empirical data. The resulting ratio between primary and secondary delays appears to vary greatly between different train types, but overall about 30% were primary and 70% secondary. Future work includes modelling and calibration of departure deviations, which vary more between different train types, and where it is more difficult to separate between primary and secondary delays. Separating distributions based on train type or location will also be considered.
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