Vetenskapliga artiklar

Vetenskapliga artiklar

Vetenskapliga artiklar

The Downside of Upkeep: Analysing Railway Infrastructure Maintenance Impact on Train Operations in Sweden

Daria Ivina & Carl-William Palmqvist, applied sciences, December 2023
Efficient and seamless railway operations depend on the systematic and well-coordinated maintenance of both rolling stock and infrastructure. However, track maintenance, or ‘trackwork’, can cause substantial delays if not properly aligned with train schedules. This study comprehensively investigates how trackwork influences train operations in Sweden. It involves an in-depth analysis of an extensive dataset comprising over 225,000 recorded instances of planned trackwork and approximately 32.5 million train passages throughout the year 2017. Multiple logistic and negative binomial regression models showed that train running time delay occurrence is higher in the sections with scheduled trackwork. Trains passing through trackwork are 1.43 times more likely to experience delays compared to trains that do not pass through scheduled trackwork. The likelihood of an opportunity for the train delay recovery passing the section with scheduled trackwork is reduced by 11%. Additionally, the frequency of train delay increase is 16% higher, and delayed recovery is 4% lower in relation to trackwork. With the number of trackwork set to increase over the coming years, these results bring attention to train scheduling and the performance of trackwork.
 
The Downside of Upkeep: Analysing Railway Infrastructure Maintenance Impact on Train Operations in Sweden
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How accessibility to schools is not (just) a transport problem: the case of public school choice in the city of Malmö, Sweden

Aaron Nichols & Jean Ryan, European Transport Research, November 2023

There is currently a lack of studies exploring how transport investments and school admission policies in a city can affect the distribution of accessibility to schools. The aim of this study is to investigate if, for whom, and the ways in which, accessibility to schools can change following (1) a change to the city’s public school admission policy and (2) investments in public transport infrastructure and adjustments to the public transport system. We draw on the case of Malmö, Sweden to examine the potential effects of these changes. This study is focused specifically on those in grades 7–9 (aged approximately 13–15), a group whose independent mobility is starting to take form. A geospatial analysis was carried out in order to compare the change in demographic makeup between school catchment areas (real and hypothetical) before and after the changes were made. The geospatial analysis utilises a cumulative opportunity accessibility model that takes into account typical public transport travel times both before and after these new measures were implemented. Findings indicate that the (hypothetical) school catchment areas have been redistributed to a considerable extent following both interventions, but particularly following the change to the public school admission policy. These redistributions have in turn resulted in changes in the socio-economic characteristics of the hypothetical school catchment areas. While the redistribution of school catchment areas could potentially change the socio-economic composition of schools in Malmö, the effects are not equally distributed throughout the city. While the addition of the new train line was the main focus of this study, it was found that other changes in the public transport system between 2018 and 2019 also played a role in determining which schools students could and could not access. The findings from this study highlight the importance of carefully considering the interaction of different effects when assessing policy alternatives.

 

 

How accessibility to schools is not (just) a transport problem: the case of public school choice in the city of Malmö, Sweden
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Spatiotemporal accessibility by public transport and time wealth: Insights from two peripheral neighbourhoods in Malmö, Sweden

Chiara Vitrano &Linnea Mellquist, Sage Journals, 2022
This paper contributes to the understanding of spatiotemporal accessibility inequalities by exploring how the current public transport (PT) provision affects the time wealth of PT users living in two peripheral neighbourhoods in Malmö. The paper investigates time-related resources and constraints that concur in defining accessibility inequalities, identifies forms of temporal disadvantage and privilege and addresses the relevance of recognizing and meeting the multiple time-related needs of (potential) PT users. Adopting a mixed-methods approach, the study integrates results from a thematic analysis of interviews and from a GIS spatiotemporal accessibility analysis of PT schedules to understand whether and how the current PT provision (a) allows users to carry out the desired or needed activities by PT in the time available to them, (b) is harmonized with their spatiotemporal access needs and (c) supports or hinders the users’ ability to control their travel time. The paper suggests that, in the observed cases, the PT provision provides unequal opportunities for faster connections and information, exposing some users to time-related transport disadvantage. Also, the current PT provision does not always seem to be harmonized with the participants’ access needs, especially during off-peak hours. The findings highlight the importance of taking into consideration the time wealth of (potential) PT users with different access needs, resources, and constraints, with the aim to both tackle transport disadvantage and support the adoption of sustainable modal choices. The study provides directions for further spatiotemporal accessibility research and for urban time and mobility policies.
 
 
Spatiotemporal accessibility by public transport and time wealth: Insights from two peripheral neighbourhoods in Malmö, Sweden
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The importance of recurring public transport delays for accessibility and mode choice

Aaron Nichols, Jean Ryan, Carl-William Palmqvist, Journal of Transport Geography Volume 115, February 2024

This paper looks at the relationship between recurring public transport delays, accessibility to jobs, and travel behaviour in the region of Scania, Sweden. The difference between potential (scheduled) accessibility, observed (actual) accessibility, and behaviour is an important part of this research. This paper contributes to the growing body of literature that uses GTFS data (for both scheduled and actual services) to provide a deeper understanding of temporal variations in accessibility with public transport. Historic public transport data were used to develop a measure for typical delays in the region. The accessibility analysis shows that, on average, recurring public transport delays result in a 4–9% reduction in accessibility to jobs in the region. The loss in accessibility varied depending on the travel time budget that was considered and the location within the region. The accessibility analysis also shows that areas with higher concentrations of households with a lower economic standard experience a smaller loss in job accessibility caused by public transport delays. However, the concentration of these effects depends on the measure that is used. The measurement of typical delays was also analysed in relation to actual trips from the regional travel survey. The statistical analysis found that recurring public transport delays were associated with a lower likelihood of using public transport compared to other motorised modes.

 
    The importance of recurring public transport delays for accessibility and mode choice
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    Understanding dwell times using automatic passenger count data: A quantile regression approach

    Ruben Kuipers, Journal of Rail Transport Planning & Management, Volume 29, March 2024

    Highlights:

    • Study shows the use of quantile regression to study dwell times.
    • The role of passenger flow characteristics and operational factors on dwell times is studied.
    • The volume of boarding passengers is shown to not be the main determining factor for dwell times
    • The importance to account for station-specific characteristics when scheduling dwell times is shown.

    Accurately scheduling dwell times is vital to ensure punctual and reliable railway services, but the stochastic nature of dwell times makes this a non-trivial task. An important step towards scheduling accurate dwell times is to gain an in-depth understanding of the mechanics that influence dwell times, which is commonly done by modelling the mean dwell time. It is, however, of more interest to understand the conditional distribution of dwell times. The study presented here proposes the use of quantile regression to study the conditional distribution of dwell times at different percentile. To do so, a year's worth of highly detailed train operation and passenger count data is used. The results indicate that the use of quantile regression over ordinary least squares regression is justifiable and beneficial. Numerical examples show the importance of arrival punctuality on dwell times, whereas the effect of the volume of boarding passengers at the critical door is limited. The results of the model presented here can help steer the discourse towards scheduling dwell times that more accurately reflect the actual situation by taking station-specific parameters into account. Doing so will help to increase the punctuality of railways and with it the attractiveness and effectiveness of railways.

    Understanding dwell times using automatic passenger count data: A quantile regression approach
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    Integrate, not compete! On Potential Integration of Demand Responsive Transport Into Public Transport Network

    Sergei Dytckov, Paul Davidsson & Jan A. Persson, 26th IEEE International Conference on Intelligent Transportation Systems, 2023,

    On-demand transport services are often envisioned as stand-alone modes or as a replacement for conventional public transport modes. This leads to a comparison of service efficiencies, or direct competition for passengers between them. The results of this work point to the positive effects of the inclusion of DRT into the public transport network. We simulate a day of operation of a DRT service in a rural area and demonstrate that a DRT system that focuses on increasing accessibility for travellers with poor public transport access can be quite efficient, especially for reducing environmental impact. We show that DRT, while it produces more vehicle kilometres than private cars would inside the DRT operating zone, can help to reduce the vehicle kilometres travelled for long-distance trips. The results of this study indicate the need for a more systemic evaluation of the impact of the new mobility modes.

     
    Integrate, not compete! On Potential Integration of Demand Responsive Transport Into Public Transport Network
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    Strategic Planning Capacities in a Time of Platformisation

    Kelsey Oldbury & Karolina Isaksson, Nordic Journal of Urban Studies, December 2023
    The influx of digital platforms into the mobility sector has created a myriad of new forms of mobility services in urban transport. The proliferation of digital platforms raises questions regarding public actors’ strategic planning capacities in times of platformisation. In this paper, focus is directed towards Mobility-as-a-Service (MaaS) as an example of platformisation taking place in a setting where public actors have (in theory) had an opportunity to influence platform developments in relation to urban and mobility planning. Based on qualitative research into a pilot project for MaaS in the Stockholm region, the aim of this paper is to provide insights into the relationship between platformisation and strategic planning. More specifically, we discuss how local and regional organisations with responsibilities for urban transport and land-use planning navigate and respond to the ongoing platformisation of urban mobility, from a strategic planning perspective. The analysis shows that local and regional planning actors generally frame the MaaS platform as beyond their sphere of responsibility. Consequently, there is a risk that public actors do not respond to the central governance and planning dilemmas that platformisation poses. Our findings also suggest that working with platforms through the lens of a pilot project forefronts practical questions of implementation over long-term strategic planning questions.
    Strategic Planning Capacities in a Time of Platformisation
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    Artificial intelligence for improving public transport: a mapping study

    Åse Jevinger, Chunli Zhao, Jan Persson & Paul Davidsson, Public Transport, July 2023

    The objective of this study is to provide a better understanding of the potential of using Artificial Intelligence (AI) to improve Public Transport (PT), by reviewing research literature. The selection process resulted in 87 scientific publications constituting a sample of how AI has been applied to improve PT. The review shows that the primary aims of using AI are to improve the service quality or to better understand traveller behaviour. Train and bus are the dominant modes of transport investigated. Furthermore, AI is mainly used for three tasks; the most frequent one is prediction, followed by an estimation of the current state, and resource allocation, including planning and scheduling. Only two studies concern automation; all the others provide different kinds of decision support for travellers, PT operators, PT planners, or municipalities. Most of the reviewed AI solutions require significant amounts of data related to the travellers and the PT system. Machine learning is the most frequently used AI technology, with some studies applying reasoning or heuristic search techniques. We conclude that there still remains a great potential of using AI to improve PT waiting to be explored, but that there are also some challenges that need to be considered. They are often related to data, e.g., that large datasets of high quality are needed, that substantial resources and time are needed to pre-process the data, or that the data compromise personal privacy. Further research is needed about how to handle these issues efficiently.

    Artificial intelligence for improving public transport: a mapping study
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    Delivering Transit Oriented Development (TOD) in low to medium density contexts. Actor relationships and market conditions in smaller Swedish cities

    Robert Hrelja & Tom Rye, International Journal of Sustainable Transportation, November 2023

    This article analyses actor relationships in Transit Oriented Development (TOD) planning in order to better understand the preconditions necessary for planning processes to result in TOD in lower density contexts, in suburbs, or small cities. Empirically, the analysis builds on a comparative case study of TOD planning projects. The focus in the analytical work is on understanding how market conditions in lower density contexts influence the conditions for TOD planning projects, and how this feeds through to planning processes. The overall conclusion is that we should not expect that planning processes in small cities with low to medium densities of populations and activities differ much from those in more ‘classic’ highly urban TOD locations. Market conditions had an impact on planning processes, but once in the planning stage conditions for implementation depended more on the ability to handle competing interests and less on market conditions. In terms of policy recommendations, it is important for actors to develop a joint vision of the built environment of the site in question that channels organizations’ individual actions in a joint direction. The ability to achieve such a joint vision for the design of the site in question may be more important in small towns than in more ‘typical’ TOD contexts in denser urban areas. This is because all enablers need to work together in a positive way in such location – which may be marginal from a market point of view – for the development to be able to go ahead.

    Delivering Transit Oriented Development (TOD) in low to medium density contexts. Actor relationships and market conditions in sm
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    Railway maintenance windows: Discrepancies between planning and practice in Sweden

    Daria Ivina & Carl-William Palmqvist, Transportation Research Interdisciplinary Perspectives, November 2023

    Efficient and timely maintenance is essential for the robust operation of infrastructure across all types of transport. In the railway sector, track maintenance presents unique challenges. Specifically, some maintenance tasks require track closures, which can disrupt train schedules. Coordinating these closures with regular train operations makes the scheduling process complicated. To ensure sufficient time for maintenance and prevent conflicts with train operations, the Swedish Transport Administration introduced “maintenance windows.” Maintenance windows, ranging from two to six hours, are periods designated for maintenance, with the track free from train operations. They are set before finalizing the annual train timetable. In this study, we examined the practical application of maintenance windows on a railway line in Southern Sweden from 2019 to 2020. Our findings reveal that while 10% of the total line capacity was allocated for maintenance windows, 11% of the capacity was used for maintenance. Alarmingly, 68% of trackwork occurred outside maintenance windows, and only 34% of the reserved maintenance window capacity was utilized. There is a significant discrepancy between the time and location reserved for maintenance windows and their actual utilization. To address this, we propose aligning maintenance windows more closely with contractor needs by 1) incorporating maintenance windows on the weekends, 2) making maintenance windows available closer to the end of the planning horizon, 3) extending the duration of some maintenance windows, and 4) designing and integrating incentives to encourage contractors to operate within planned maintenance windows.

    Railway maintenance windows: Discrepancies between planning and practice in Sweden