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  • Genell, Anders
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Gustafson, Andreas
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Källdata för elfordon: Analys av tillgängliga data i litteraturen och deras lämplighet för Nord2000 i Sverige2026Report (Other academic)
    Abstract [sv]

    Andelen elfordon har ökat de senaste åren och kommer enligt prognoser att ytterligare öka markant de kommande åren. I den gällande ”Användarhandledning för beräkning av buller från väg- och spårtrafik för svenskt bruk, Version 1.0 2024-12-20” presenteras källdata för elfordon som baseras på befintliga data från olika projekt där buller från enstaka fordon mätts. Denna rapport presenterar en genomgång av publicerade data för bulleremission från elfordon som underlag för eventuell komplettering av de som ingår i användarhandledningen, inklusive analys av hur väl publicerade data tar hänsyn till olika mekanismer och utstrålningsegenskaper samt hur väl de är lämpade för svenska förhållanden.

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  • Razaq, Bosinuola Sherifat
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes. Communications and Transport Systems, Department of Science and Technology, Linköping University, Sweden.
    The influence of organisational dependencies and planning frameworks on construction and demolition (C&D) waste circularity in Sweden2026Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    The purpose of this thesis is to examine how organizational dependencies, legal frameworks and planning processes influence construction and demolition (C&D) waste circularity in the construction and demolition ecosystem. As global population growth continues to drive increasing demand for construction, society is constantly faced with more transport needs, more emissions and more resource use. In this context, the circular economy principles promise a potential way to mitigate this by promoting the reuse of construction and demolition materials. Existing studies have noted that the construction industry can implement the principles of the circular economy, but the progress in practice remains limited; as such, there is an overarching need to increase circularity in the construction sector. Previous studies have made important contributions by identifying a wide range of barriers influencing construction industry circularity—spanning regulation, organization, material quality, and information sharing. These barriers are not isolated phenomena; instead, they are deeply embedded within networks of actor dependences shaped by organizational structures and planning frameworks (legislation and planning processes). Advancing construction circularity, therefore, requires a comprehensive understanding of how actors relate to one another, coordinate across the organization, and collaborate. In addition, addressing legislative barriers requires not only examining the legislation itself but also understanding how this legislation interacts with the practical realities of industry actors.

    Therefore, this study follows the research questions:

    RQ 1: How do actors’ dependencies within the construction/demolition ecosystem influence the advancement of circularity

    RQ 2: How do planning processes and legal frameworks affect the advancement of construction material circularity?

    To answer these research questions, the study has followed a qualitative approach. The study is based on semi-structured interviews, surveys, documents, and observations.

    The thesis argues that dependencies are not static but dynamic over a project timeline, and that a limited understanding of shifting dependencies across organizational levels and actors (which is fluid) creates bottlenecks to advancing construction circularity. Internal fragmentation and knowledge gaps regarding material quality hinder strategic decision-making. To address these challenges, investment in material digital passports and better internal collaborations will enable increased circularity. For increased reuse, pre-construction and post-construction should be considered with utmost importance. Furthermore, existing legislation is too abstract to drive circularity in the construction industry; advancing construction circularity will depend on specific, strong, and aligned EU-level rules. The presence of multiple policy documents, and municipalities navigating this, creates complexity that challenges actors in the reuse of (C&D) waste. Overall, this study extends ecosystem theory to the complex, project-based context of C&D waste management and offers managers and policymakers a diagnostic tool to identify critical dependencies before projects begin, thereby increasing circularity. In addition, the thesis identified a governance gap in circularity implementation, evidenced by the absence of a dedicated role for C&D waste management at the municipal level.

    List of papers
    1. Circularity of Aggregate Materials in the Construction Sector: Drivers & Barriers
    Open this publication in new window or tab >>Circularity of Aggregate Materials in the Construction Sector: Drivers & Barriers
    2024 (English)In: 36th annual NOFOMA conference, Stockholm, Sweden, June 13–14, 2024, 2024Conference paper, Oral presentation only (Other academic)
    Abstract [en]

    Purpose: There is an overarching need to increase circularity in the construction sector, but not much is happening and only 1% of aggregate materials are being reused. Different construction actors can impact circularity, but their drivers and barriers are still unknown. Therefore, the purpose of this study is to explore how different drivers and barriers impactthe circular use of aggregate materials.

    Design/methodology/approach: The purpose of this research was achieved using a qualitative approach based on three workshops and four interviews in Östergötland, Sweden.

    Findings: The study found that drivers and barriers of circular aggregate materials can be thematically grouped into eight themes. Based on those findings, we propose a three-step model to increase circularity of aggregates; 1. Plan for mass handling spaces in the strategic municipalplans; 2. Develop common definitions of circular aggregate materials that corresponds tothose of virgin materials; 3. Develop and introduce (digital) information systems to increase the capacity of matching aggregates.

    Research limitations/implications: This study was based on workshops and interviews with established organizations within the Östergötland region. Future research should include other regions, and the view of the local small construction firms or mass handlers etc.

    Practical implications: This study helps organizations to understand how they can work towards circular aggregate materials in collaboration with other organizations in a structured way.

    Original/value: This study is one of the first in-depth studies that investigates drivers and barriers of circular reuse of aggregate materials in construction.

    Keywords
    mass logistics, circular aggregate flows, drivers and barriers, organizations
    National Category
    Transport Systems and Logistics Construction Management
    Identifiers
    urn:nbn:se:vti:diva-21102 (URN)
    Conference
    36th annual NOFOMA conference, Stockholm, Sweden, June 13–14, 2024.
    Available from: 2024-06-26 Created: 2024-07-03 Last updated: 2026-06-04Bibliographically approved
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  • Ragipi Rushid, Ajsuna
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics. Economics, Department of Management and Engineering, Linköping University, Sweden.
    Marginal Infrastructure Costs and Pricing in Road and Rail Transport2026Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This licentiate thesis examines marginal cost estimation and pricing in transport infrastructure, with empirical applications to Swedish roads and railways. The thesis consists of three papers addressing how infrastructure charges can be aligned with short-run marginal social costs.

    The first paper estimates marginal road renewal costs per heavy vehicle kilometre using panel data on approximately 1.3 million 100-meter road segments (1999–2022). A two-part discrete–continuous framework is applied, combining models of renewal timing (probit and Weibull survival specifications) with renewal expenditures (a log-log function). The results show substantial heterogeneity in marginal renewal costs across road types, with heavy vehicles generating higher costs on low-standard roads than on motorways or other high-standard roads.

    The second paper estimates short-run marginal road maintenance costs per heavy vehicle kilometre using administrative maintenance data at the Maintenance District Unit (MDU) level (2015–2024). A log-log cost function relates annual maintenance expenditure to heavy-vehicle traffic intensity by road type, controlling for network scale and weather conditions. The results indicate that the marginal maintenance cost per heavy vehicle kilometre is about 50 percent higher on low-standard roads than on high-standard roads. Combined with the renewal estimates from Paper 1, total marginal infrastructure costs range from 0.03 €/heavy-vkm on motorways to 0.51 €/heavy-vkm on low-standard roads, indicating that the marginal infrastructure cost imposed by heavy vehicles varies greatly across the road network.

    The third paper analyses optimal rail access charges in a vertically separated railway market, where marginal capacity costs reflect track congestion. A calibrated demand and supply model for the Stockholm–Gothenburg corridor is used to simulate how track charges affect fares, frequencies, welfare, and modal competition. The results show that increases in track charges to reflect the marginal cost of congestion primarily reduce service frequency rather than substantially increasing fares, with welfare-optimal charges depending critically on congestion externalities.

    Together, the papers show that marginal infrastructure pricing requires both disaggregated cost estimates and an understanding of how transport operators respond to infrastructure charges.

    List of papers
    1. The impact of optimal rail access charges on frequencies and fares
    Open this publication in new window or tab >>The impact of optimal rail access charges on frequencies and fares
    2021 (English)In: Economics of Transportation, ISSN 2212-0122, E-ISSN 2212-0130, Vol. 26-27, article id 100217Article in journal (Refereed) Published
    Abstract [en]

    Sweden has been a front runner in vertical separation. We use data from the business long-distance corridor in Sweden to calibrate and define a demand and supply model. We simulate how the profit, welfare, fares, frequencies, modal shares and train size depend on the level of the track charges. We simulate the welfare optimal track charges, given different levels of congestion on the track, hence using the charges as a pricing instrument to allocate the train slots efficiently. We find that increases in charges have a limited impact on fares but larger impacts on the frequency. When the length of the trains can be extended and when the crowding penalty is high, the impact of higher track charges on the frequencies is larger. Higher track charges increase the length of the trains if possible. The intermodal competition from road and air has a significant impact on rail fares. © 2021 The Authors

    Place, publisher, year, edition, pages
    Elsevier Ltd, 2021
    National Category
    Transport Systems and Logistics
    Identifiers
    urn:nbn:se:vti:diva-16843 (URN)10.1016/j.ecotra.2021.100217 (DOI)2-s2.0-85109040659 (Scopus ID)
    Available from: 2021-08-23 Created: 2021-08-23 Last updated: 2026-06-04Bibliographically approved
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  • Public defence: 2026-08-25 13:00 K3, Campus Norrköping
    Klar, Robert
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics. Communications and Transport Systems, Department of Science and Technology, Linköping University, Sweden.
    Digital Twins and Explainable AI for Decision Support in Port and Maritime Operations2026Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Ports are actively pursuing greater operational efficiency to handle the increasing global flow of goods, while simultaneously improving the energy efficiency of their operations to comply with new environmental regulations. As a result, innovation-leading ports have begun to recognize the potential of digital twins to monitor, coordinate, and optimize port processes, enabling energy savings and reductions in both costs and CO2 emissions. Although digital twins have gained significant momentum in other domains, such as smart manufacturing and aerospace, their adoption in ports remains challenging. This can be explained by the multi-stakeholder nature of ports and the high complexity of their interconnected processes, requiring decision-making across organizational boundaries.

    Grounded in the port context, this thesis examines what constitutes a digital twin, proposes a framework to assess the maturity of existing port digital twins, and develops modeling and explainable AI-enabled decision support components for port and maritime operations. These components span seaside, quay, yard, and gate processes and can serve as building blocks of future port digital twin implementations. The thesis consists of six papers:

    Paper 1 provides an in-depth literature review of digital twins across multiple domains and transfers insights from these to the port domain. The paper outlines how digital twins can enhance operational efficiency and support energy savings in ports. It also identifies the characteristics and design requirements that a port-specific digital twin must fulfill. Based on these findings, the paper proposes a tailored definition of a digital twin for the port domain.

    Paper 2 discusses how digital twins’ maturity can be assessed within six maturity levels and presents milestones for their implementation. Notably, Interoperability is identified as the highest maturity level,as the numerous stakeholders and their respective digital twins must work together to reach a coordinated system of systems performance. Using this assessment demonstrates that only a few innovation-leading ports have developed sophisticated digital twinning solutions so far.

    Paper 3 focuses on container retrieval, balancing two competing objectives: minimizing yard crane moves and adhering to tight truck scheduling. This reflects the conflicting perspectives of different stakeholders in the port context. The provided optimization model and heuristic algorithm demonstrate that addressing both problems simultaneously may result in reduced efficiency of the individual objectives. However, from a systems perspective, this approach leads to higher overall port efficiency.

    Paper 4 examines quay cranes at the system level by developing an explainable AI framework to predict whether a quay crane will experience a breakdown during vessel operations. Using monitoring data, operational data, and weather observations, the study identifies how operational intensity, hoist-related warning patterns, and environmental conditions jointly influence the likelihood of a breakdown. This system-level predictive capability enhances situational awareness and enables early identification of disruptions.

    Paper 5 builds on Paper 4 by focusing on the prediction of individual critical error events. Rather than assessing the overall likelihood of a breakdown, the model identifies which error type is likely to occur next and estimates its timing. Using eXtreme Gradient Boosting with lagged error sequences, operational data, and weather conditions, the study offers component-level insights that complement the systemlevel prediction in Paper 4 and support more targeted maintenance interventions.

    Paper 6 expands the perspective beyond ports by analyzing fuel consumption in inland ferry operations using GPS-derived trip legs and journeys enriched with environmental data. Combining unsupervised clustering to uncover operational patterns with supervised learning and SHAP-based explainability, the study identifies operational speed as the dominant driver of fuel consumption and links consumption patterns to individual captains’ driving behavior. This contributes to maritime decision-making by enabling targeted interventions such as eco-driving strategies.

    Together, these six papers contribute a conceptual grounding of port digital twins, provide a tool for their assessment, and provide modeling components to aid in port and maritime decision-making.

    List of papers
    1. Digital Twins for Ports: Derived From Smart City and Supply Chain Twinning Experience
    Open this publication in new window or tab >>Digital Twins for Ports: Derived From Smart City and Supply Chain Twinning Experience
    2023 (English)In: IEEE Access, E-ISSN 2169-3536, Vol. 11, p. 71777-71799Article in journal (Refereed) Published
    Abstract [en]

    Ports are striving for innovative technological solutions to cope with the ever-increasing growth of transport, while at the same time improving their environmental footprint. An emerging technology that has the potential to substantially increase the efficiency of the multifaceted and interconnected port processes is the digital twin. Although digital twins have been successfully integrated in many industries, there is still a lack of cross-domain understanding of what constitutes a digital twin. Furthermore, the implementation of the digital twin in complex systems such as the port is still in its infancy. This paper attempts to fill this research gap by conducting an extensive cross-domain literature review of what constitutes a digital twin, keeping in mind the extent to which the respective findings can be applied to the port. It turns out that the digital twin of the port is most comparable to complex systems such as smart cities and supply chains, both in terms of its functional relevance as well as in terms of its requirements and characteristics. The conducted literature review, considering the different port processes and port characteristics, results in the identification of three core requirements of a digital port twin, which are described in detail. These include situational awareness, comprehensive data analytics capabilities for intelligent decision making, and the provision of an interface to promote multi-stakeholder governance and collaboration. Finally, specific operational scenarios are proposed on how the port's digital twin can contribute to energy savings by improving the use of port resources, facilities and operations.

    Place, publisher, year, edition, pages
    IEEE, 2023
    Keywords
    Digital twin, IoT, smart city, smart port, supply chain, INTEGRATED BERTH ALLOCATION, QUAY CRANE ASSIGNMENT, ENERGY MANAGEMENT, DECISION-SUPPORT, CHALLENGES, TECHNOLOGIES, SYSTEM, OPERATIONS, EFFICIENCY, LOGISTICS
    National Category
    Transport Systems and Logistics
    Identifiers
    urn:nbn:se:vti:diva-19834 (URN)10.1109/ACCESS.2023.3295495 (DOI)001035836900001 ()2-s2.0-85164811315 (Scopus ID)
    Funder
    Swedish Transport Administration, 2019.2.2.16
    Available from: 2023-08-16 Created: 2023-08-16 Last updated: 2026-06-04Bibliographically approved
    2. Digital Twins' Maturity: The Need for Interoperability
    Open this publication in new window or tab >>Digital Twins' Maturity: The Need for Interoperability
    2024 (English)In: IEEE Systems Journal, ISSN 1932-8184, E-ISSN 1937-9234, Vol. 18, no 1, p. 713-724Article in journal (Refereed) Published
    Abstract [en]

    Digital twins have gained tremendous momentum since their conceptualization over 20 years ago, as more and more domains discover their value in driving efficiencies and reducing costs, while enabling technologies continue to advance. Originally aimed at product optimization and intelligent manufacturing, the range of applications for digital twins now spans entire complex, often highly interconnected systems such as ports, cities, and supply chains. Despite the increasing demand for sophisticated digital twinning solutions across all domains and scopes, their development is often still constrained by differing definitions, different understandings of their functional scope and design, and a lack of concrete methodology toward implementing a comprehensive digital twinning solution. Although there are already papers that evaluate the capabilities of existing digital twinning solutions on the basis of maturity levels, these usually consider the object to be twinned in isolation and are often domain-specific. With this article we address exactly this gap discussing how interoperability of digital twins can break physical boundaries of an isolated system, enabling system of systems joint optimization. We therefore consider interoperable digital twins to be the most mature twinning platforms, thus, we discuss in detail six digital twin maturity levels, departing from the interrelated contexts of ports, cities, and supply chains. Examples drawn from these domains demonstrate the need for interoperability toward optimizing processes and systems in realistic contexts, rather than in assumed isolation. 

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2024
    Keywords
    Digital twin (DT) maturity, interoperability, smart cities, ports, supply chains
    National Category
    Computer Sciences
    Identifiers
    urn:nbn:se:vti:diva-20137 (URN)10.1109/jsyst.2023.3340422 (DOI)001129770400001 ()2-s2.0-85181555264 (Scopus ID)
    Funder
    Swedish Transport Administration, 2019.2.2.16EU, Horizon Europe, 101057779
    Available from: 2024-01-16 Created: 2024-01-16 Last updated: 2026-06-04Bibliographically approved
    3. Container Relocation and Retrieval Tradeoffs Minimizing Schedule Deviations and Relocations
    Open this publication in new window or tab >>Container Relocation and Retrieval Tradeoffs Minimizing Schedule Deviations and Relocations
    2024 (English)In: IEEE Open Journal of Intelligent Transportation Systems, E-ISSN 2687-7813, Vol. 5, p. 360-379Article in journal (Refereed) Published
    Abstract [en]

    Ports are striving to improve operational efficiency in the context of constantly growing volumes of trade. In this context, port terminal storage yard operation is key, since complexity and poor coordination lead to containers stacked without consideration of retrieval schedules, resulting in time and energy-consuming reshuffling operations. This problem, known as the block relocation (and retrieval) problem (BRP), has recently gained considerable attention. Indeed, there are promising solutions to the BRP. However, the literature views the problem in isolation, optimizing one operational parameter for one of the many port stakeholders. This often leads to efficiency losses since port processes involve different stakeholders and port parts. In this work, we explicitly focus on scheduling trucks for pick-up for hinterland distribution. Appointments are often postponed in order to minimize reshuffling operations, leading to losses for the transport forwarders and decreasing the competitiveness of the port.

    We discuss the trade-off between minimizing container reshuffling operations while maintaining scheduled time windows for container retrieval. We describe the multi-objective optimization problem as a weighted sum of the two objectives. Given the complexity of the problem, we also present a greedy heuristic. Our results indicate that the number of schedule deviations can be reduced without significantly affecting the number of relocations compared to solutions that consider only the latter. Ideally, a weighting of 0.4 and 0.6 should be applied, reflecting schedule deviations and relocations, respectively, to achieve the highest joint optimization potential. This demonstrates that in complex environments, such as ports, with multiple interacting stakeholders and processes, coordination of solutions yields significant benefits.

    Place, publisher, year, edition, pages
    Institute of Electrical and Electronics Engineers (IEEE), 2024
    Keywords
    Container Relocation Problem, Containers, Digital Twins, Logic gates, Optimization, Optimization, Ports, Schedule Deviations, Schedules, Seaports, Stacking, Stakeholders
    National Category
    Transport Systems and Logistics Information Systems
    Identifiers
    urn:nbn:se:vti:diva-21071 (URN)10.1109/ojits.2024.3413197 (DOI)001276383900002 ()2-s2.0-85196073772 (Scopus ID)
    Funder
    Swedish Transport Administration, 2019.2.2.16
    Available from: 2024-06-27 Created: 2024-06-27 Last updated: 2026-06-04Bibliographically approved
    4. Understanding and predicting quay crane breakdowns using explainable AI
    Open this publication in new window or tab >>Understanding and predicting quay crane breakdowns using explainable AI
    2026 (English)In: Maritime Transport Research, ISSN 2666-822X, Vol. 10, article id 100152Article in journal (Refereed) Published
    Abstract [en]

    Quay cranes (QCs) play a vital role in ship-to-shore operations, enabling the seamless transfer of cargo between sea and land. However, increasing trade volumes require faster and more cost-effective container handling, exerting significant pressure on QCs and leading to greater wear on critical components such as wires, hoists, and rope clamps. While operations research has explored maintenance scheduling to improve terminal performance, comparatively little work has examined how machine learning can exploit the growing volume of QC monitoring and operational data to predict breakdowns before they occur. This study contributes to this area by integrating terminal operations data, QC monitoring logs, and meteorological observations into a unified analytical framework. We employ explainable artificial intelligence (XAI), using both global and local SHapley Additive exPlanations (SHAP) to identify the operational and environmental factors most strongly associated with QC failures and to illustrate concrete, instance-level examples of how specific conditions contribute towards breakdowns. In parallel, we develop a robust machine learning pipeline built around nested cross-validation to assess the predictive capability of multiple classifiers for forecasting QC breakdowns. Our XAI analysis reveals that breakdown risk is closely linked to QC working time, the distribution of moves across simultaneously operating QCs, hoist overload and trolley alignment warnings, and adverse weather conditions. Among the evaluated models, LightGBM achieved the highest predictive accuracy, reaching up to 83% in identifying breakdown-prone scenarios. These findings demonstrate the feasibility and value of data-driven predictive maintenance for QCs, providing insights that support safer, more reliable, and more efficient terminal operations. 

    Place, publisher, year, edition, pages
    Elsevier, 2026
    Keywords
    Quay cranes, Container terminal operations, Breakdown prediction, Predictive maintenance, Machine learning, Explainable artificial intelligence (XAI), Port performance
    National Category
    Transport Systems and Logistics Artificial Intelligence
    Identifiers
    urn:nbn:se:vti:diva-22620 (URN)10.1016/j.martra.2026.100152 (DOI)
    Funder
    Swedish Transport Administration
    Note

    Research funding provided by The Swedish Transport Administration through the Triple F project MODIG-TEK (2019.2.2.16). 

    Available from: 2026-05-18 Created: 2026-05-18 Last updated: 2026-06-04Bibliographically approved
    5. Predicting Error Types and Timing in Quay Crane Operations with eXtreme Gradient Boosting
    Open this publication in new window or tab >>Predicting Error Types and Timing in Quay Crane Operations with eXtreme Gradient Boosting
    2026 (English)In: The 20th Annual IEEE International Systems Conference: Conference Proceedings, IEEE, 2026Conference paper, Published paper (Refereed)
    Abstract [en]

    Efficient port operations depend on the disruption free operation of quay cranes (QCs), which transfer containers between vessels and internal trucks. As global container through put rises, QCs face increased pressure, resulting in accelerated wear and tear. This can lead to QC downtime, which could interrupt the entire chain of port operations. Therefore, timely identification and prediction of critical errors is essential to enable timely maintenance to lower the risk of downtime. This study utilizes two years of QC monitoring data, enriched with weather conditions and terminal operational context, alongside twenty critical error events identified by the terminal operator. The goal is to predict the occurrence and timing of these critical errors through a three-stage machine learning model. The first stage predicts the type of the next critical event based on historical error patterns, warnings, and contextual data. The second stage estimates a time window in which the event will occur. The third stage refines timing predictions when more than one hour remains. The first two stages are formulated as multiclass classification problems, and the third as a regression task. All stages utilize eXtreme Gradient Boosting (XGBoost). SHapley Additive exPlanations (SHAP) are used to identify influential features. Results show that the model predicts the next critical error type with 83% accuracy and its immediacy with 71% accuracy. However, approximating the timing of events anticipated to occur beyond one hour remains challenging. These findings support proactive maintenance planning and operational adjustments, helping port operators mitigate disruptions and enhance QC reliability.

    Place, publisher, year, edition, pages
    IEEE, 2026
    Series
    Annual IEEE Systems Conference, ISSN 1944-7620, E-ISSN 2472-9647
    Keywords
    eXtreme Gradient Boosting (XGBoost), Machine Learning, Predictive Maintenance, Quay Cranes, Resilient Port Operations
    National Category
    Transport Systems and Logistics
    Identifiers
    urn:nbn:se:vti:diva-22608 (URN)10.1109/SysCon66367.2026.11503482 (DOI)9798331591519 (ISBN)9798331591526 (ISBN)
    Conference
    20th Annual IEEE International Systems Conference (SYSCON 2026), Halifax, Canada, April 6-9, 2026.
    Funder
    Swedish Transport Administration
    Note

    Research funding provided by The Swedish Transport Administration through the Triple F project MODIG-TEK (2019.2.2.16). 

    Available from: 2026-04-30 Created: 2026-04-30 Last updated: 2026-06-04Bibliographically approved
    6. Fuel efficiency in ferry services: GPS-based clustering and explainable AI
    Open this publication in new window or tab >>Fuel efficiency in ferry services: GPS-based clustering and explainable AI
    2026 (English)In: Transportation Research Part D: Transport and Environment, ISSN 1361-9209, E-ISSN 1879-2340, Vol. 157, article id 105403Article in journal (Refereed) Published
    Abstract [en]

    Enhancing fuel efficiency in ferry operations is essential for reducing emissions and advancing maritime sustainability. This study presents a data-driven framework that uses second-level GPS data enriched with operational and environmental variables to identify and explain fuel consumption patterns. Vessel movements are segmented into trip legs and journeys, and operational metrics such as speed, wind exposure, and fuel use are computed. A hybrid machine learning approach combines unsupervised clustering to detect recurring operational patterns with gradient boosting models and explainable methods to quantify feature impacts. The framework achieves strong performance, with a cluster classification accuracy of 94 percent and a coefficient of determination of 0.97 for fuel prediction. Results indicate that operational speed is the dominant driver of fuel consumption, while analysis of captain assignments reveals the influence of human factors. The proposed framework provides actionable insights for speed management and operational optimization, enabling cost-effective emission reductions in ferry services.  

    Place, publisher, year, edition, pages
    Elsevier, 2026
    Keywords
    Fuel efficiency, Ferry operations, Maritime sustainability, Explainable artificial intelligence, Extreme gradient boosting, Hierarchical density-based clustering
    National Category
    Transport Systems and Logistics Artificial Intelligence
    Identifiers
    urn:nbn:se:vti:diva-22618 (URN)10.1016/j.trd.2026.105403 (DOI)001765014200001 ()2-s2.0-105037879285 (Scopus ID)
    Projects
    REISFER
    Funder
    Swedish Transport AdministrationInterreg Central Baltic, CB0300186
    Note

    Research funding provided by The Swedish Transport Administration through the Triple F project MODIG-TEK (2019.2.2.16). 

    Available from: 2026-05-11 Created: 2026-05-11 Last updated: 2026-06-04Bibliographically approved
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  • Vitrano, Chiara
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Henriksson, Malin
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Alm, Jens
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Ihlström, Jonas
    Swedish National Road and Transport Research Institute, Traffic and road users, The Human in the Transport system..
    Kębłowski, Wojciech
    Department of Urban Planning and Design, Faculty of Architecture, University of Hong Kong, Hong Kong; Cosmopolis Centre for Urban Research, Brussels Centre for Urban Studies, Vrije Universiteit, Brussels, Belgium.
    Challenges in public transport labour: understanding and improving bus drivers’ working conditions2026In: Mobility and transport planning challenges in the Nordic context: Essays from a Nordic Symposium / [ed] Robert Hrelja; Christina Lindkvist, Malmö universitet, 2026, p. 44-48Conference paper (Other academic)
    Abstract [en]

    Public transport (PT) is pivotal for sustainable development, ensuring accessibility in urban and rural areas while reducing CO₂ emissions and contributing to sustainable cities (SDG 11). Its functioning, and the functioning of our societies more broadly, relies on the everyday work of PT workers. Despite this central role, PT work across Europe, including the Nordic region, faces a crisis pertaining to working conditions and labour supply. 

    In Sweden, trade unions and workers report poor working conditions, citing long and stressful working days and inadequate time and spaces for resting. At the same time, PT operators face acute staff shortages (primarily drivers, but also mechanics, traffic controllers, and technicians), leading to frequent service disruptions. Operators estimate a need for 8,100 new bus drivers before 2026 to guarantee adequate service levels. A comparable scenario can be observed in other Nordic countries, such as Denmark and Norway. 

    This shortage is expected to worsen due to a forthcoming wave of retirements, driven by the high average age of bus drivers: in 2023, 62% of tram and bus drivers in Sweden were over 50, and only 3% under 30. Despite efforts to attract women, the sector remains highly male-dominated (88% of drivers in 2023), and women’s participation declined by 10% between 2016 and 2023. Research highlights barriers for women, including atypical hours and lack of safe transport options. Recruitment and retention of women and younger drivers remain major concerns. 

    Understanding bus drivers’ working conditions – and how these intersect with gender, age, and other inequalities shaping experiences and coping strategies – is a priority for transport and mobility research. This knowledge is essential for enhancing workers’ well-being, making the profession more attractive, and ensuring the sustainability of PT.

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  • Balkmar, Dag
    et al.
    Institutionen för humaniora, utbildnings- och samhällsvetenskap, Örebro universitet, Sverige.
    Edberg, Karin
    Technology and Social Change, Department of Thematic Studies, Linköping University, Sweden.
    Henriksson, Malin
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Paulsson, Alexander
    Organizational Studies, Department of Business Administration, Lund University School of Economics and Management, Lund University, Sweden.
    Wappelhorst, Annika
    Department of Communication and Behavioural Sciences, School of Education and Communication, Jönköping University, Sweden.
    Pedal powered frictions: co-thinking cycling as a transformer and maintainer of power relations2026In: Mobility and transport planning challenges in the Nordic context: Essays from a Nordic Symposium / [ed] Robert Hrelja; Christina Lindkvist, Malmö universitet, 2026, p. 11-14Conference paper (Other academic)
    Abstract [en]

    Any transitions towards more sustainable transport systems requires shifts from car dependency to less carbon-dependent forms of mobilities. In Nordic policy and planning discourse, cycling is often presented as a key component in advancing sustainable and equal transport and to challenge the dominance of the private car. However, even in countries like Sweden, where cycling is considered ‘normal’, cycling remains marginalized vis-à-vis the hegemonic position of the motor car and differences in cycling practices that mirror structural inequalities can be noted. The car norm still prevails, even if negative aspects such as emissions, congestion and risks for public health are increasingly recognized. While cycling is often considered a low-cost and universally accessible mode of transport, and policy pledges are raised to foster social inclusion, in reality, the cycling mobility system does not provide equal access for everyone. Against this background, there is a need to critically consider what a pedal powered mobility future may entail in a Nordic perspective, including some of the ‘frictions’ that needs further scholarly and political attention.  

    In this piece, we take such ‘pedal-powered frictions’ as our joint starting point to co-think upon how and in what ways cycling act as a transformer and maintainer of power relations. Our methodology is to use the ongoing ‘multivocal’ and multidisciplinary discussions in a recently formed cycling research network. While cycling research may take many forms, ranging from a focus on optimization of infrastructure and safety to cycling uptake and identity formation, we address cycling primarily from a social and critical perspective. 

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  • Fager, Hanna
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Järlskog, Ida
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Gunnarsson, Martin
    Svevia, Sverige.
    Danell, Julia
    Svevia, Sverige.
    Aneklev, Niklas
    Stripe Hog Scandinavia, Sverige.
    Återvinning av termoplastisk vägmarkering2026Report (Other academic)
    Abstract [en]

    Thermoplastic road markings are essential for traffic safety, but their production has a significant environmental impact, particularly due to components that require energy-intensive production, such as pigments, binders, and glass beads. As resource awareness increases and new knowledge emerges about the climate impact of road markings, the need for more sustainable use of road marking materials has grown. At the same time, larger quantities of thermoplastic road markings are removed during maintenance operations, raising the question of whether recycling could be a viable alternative to decrease resource use, decrease climate impact and lower costs. Systematic recycling is not currently practiced, and the level of knowledge regarding the recycling of thermoplastic road markings is very limited. 

    This pilot project aims to investigate whether it is possible to recycle thermoplastic road markings: from road removal and contaminant separation to evaluation of recovered components and functional testing in real traffic environments. Two removal methods were analyzed: mechanical milling and high-pressure water blasting. Milling produced coarser pieces of marking material but with large amounts of contaminants such as asphalt and gravel, while water blasting produced fine-grained material with significant contamination in the form of clay and bitumen.

    After sorting, washing, and re-melting, the recycled material was used in new thermoplastic formulations containing 10–30 % recycled content. Laboratory analyses show large variations between the materials, particularly in binder, pigment, and premix content, highlighting the need for careful quality control and well-adapted recycling processes. Three of the most promising formulations were applied in autumn 2024 on NordicCert’s test site in Norway. 

    The project shows that recycling thermoplastic road markings is technically feasible, but that effective and proper separation of contaminants from the marking material is a challenge. The results also indicate that recycled material can be used in new road marking products, but further development is required for process optimization, quality assurance, and assessment of long-term performance. Continued evaluation at the test field over the coming years is essential to determine whether road markings containing recycled components can meet functional and durability requirements in Nordic climates. 

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  • Lin, Peng
    et al.
    Section of Pavement Engineering, Department of Engineering Structures, Faculty of Civil Engineering and Geosciences, TU Delft, the Netherlands.
    Airey, Gordon
    Nottingham Transportation Engineering Centre (NTEC), Department of Civil Engineering, Faculty of Engineering, University of Nottingham, UK.
    Buchner, Johannes
    Braunschweig Pavement Engineering Centre, Faculty of Architecture, Civil Engineering and Environmental Sciences, TU Braunschweig, Germany.
    Grothe, Hinrich
    Research Group for Atmospheric Physical Chemistry, Research Unit of Physical Chemistry, Institute of Materials Chemistry, TU Wien, Austria.
    Hagos, Eyassu
    Boskalis, the Netherlands.
    Kakumanu, Lakshmi Roja
    Nottingham Transportation Engineering Centre (NTEC), Department of Civil Engineering, Faculty of Engineering, University of Nottingham, UK.
    Kokken, Isabeau
    Sustainable Pavements and Asphalt Research, Faculty of Applied Engineering, University of Antwerp, Belgium.
    Li, Bowen
    Research Unit of Road Engineering, Institute of Transportation, Faculty of Civil and Environmental Engineering, TU Wien, Austria.
    Liu, Xueyan
    Section of Pavement Engineering, Department of Engineering Structures, Faculty of Civil Engineering and Geosciences, TU Delft, the Netherlands.
    Miljković, Miomir
    Faculty of Civil Engineering and Architecture, University of Niš, Serbia.
    Mortier, Lucas
    Research Group for Atmospheric Physical Chemistry, Research Unit of Physical Chemistry, Institute of Materials Chemistry, TU Wien, Austria.
    Mouillet, Virginie
    Cerema, Aix-en-Provence, France.
    Nahar, Sayeda
    Building Materials and Structures, Unit of Mobility & Built Environment, TNO, Delft, the Netherlands.
    Pipintakos, Georgios
    Sustainable Pavements and Asphalt Research, Faculty of Applied Engineering, University of Antwerp, Belgium.
    Škulteckė, Judita
    Road Research Institute, Faculty of Environmental Engineering, Vilnius Tech, Lithuania.
    Weigel, Sandra
    Department of Safety of Structures, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany.
    Wu, Rui
    Section of Pavement Engineering, Department of Engineering Structures, Faculty of Civil Engineering and Geosciences, TU Delft, the Netherlands.
    Zhu, Jiqing
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    UV and Thermal-Oxidative Ageing of SBS-Modified Binders: An Interlaboratory Study of Chemical and Rheological Response2026Conference paper (Refereed)
    Abstract [en]

    Polymer-modified binders are widely used in asphalt pavements, but their long-term performance and recyclability depend on how they age under both thermo-oxidative and photo-thermal conditions. Within RILEM TC 307-PPB, Task Group 2 (TG2) has set up an interlaboratory programme to compare a reference RTFOT+PAV ageing condition (PAV40) with a well-defined RTFOT+UV condition (UVA72) for two industrial SBS-modified binders with different SBS contents. Ageing was carried out centrally at TU Delft and the binders were characterised in ten laboratories using FTIR spectroscopy, BTSV rheological measurements and fluorescence microscopy. FTIR band indices indicate that PAV40 and UVA72 bring both binders to a similar overall oxidation level, while the balance between matrix oxidation and polymer-related changes depends on SBS content. BTSV results show comparable high-temperature stiffening for PAV40 and UVA72, with binder-dependent but modest differences. The interlaboratory data reveal larger scatter of FTIR indices for UVA72, and additional tests on solid and homogenised UV-aged films point to finite UV ageing depth and sampling/homogenisation procedures as important contributors. Fluorescence microscopy provides a qualitative microstructural counterpart and confirms the sensitivity to preparation protocols. Together, these findings offer an interlaboratory reference for relating UV and PAV ageing of SBS-modified binders and underline the need for clearly defined UV ageing and sampling procedures in future TG2 pre-standardisation work.

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  • Hebbar, Anish
    et al.
    World Maritime University, Malmö, Sweden.
    Tugume, Clever
    World Maritime University, Malmö, Sweden.
    Schröder-Hinrichs, Jens-Uwe
    World Maritime University, Malmö, Sweden.
    Vierth, Inge
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Consequences of ship collisions in Swedish waters: A Coastal State risk management perspective2026Report (Other academic)
    Abstract [en]

    Ship collisions remain a persistent safety concern in high-density and geographically constrained maritime regions such as the Baltic Sea. This study examines collision risk in Swedish waters using multiple sources, integrating accident data from Transportstyrelsen with the operational activity data that the Swedish National Road and Transport Research Institute VTI calculated based on HELCOM’s AIS-data and supplementary environmental and economic datasets. A total of 525 collision occurrences (2011–2023) were analysed, with a harmonised subset of 429 collisions subjected to exposure normalised assessment. Collision frequencies were normalised against three measures of activity which include distance sailed, operational time and number of unique ships to provide strong interpretation of risk beyond absolute accident counts. The results show that collision occurrence is primarily driven by operational exposure and navigational context, with passenger ships exhibiting the highest collision rates due to intensive operations in confined and high traffic density environments. Dry cargo ships display more stable and proportional risk patterns, while tanker collisions are characterised by low frequency but high variability, limiting trend-based interpretation. Scenario analysis identifies three dominant risk structures such as high-frequency, low-severity operational collisions, interaction driven collisions with higher severity potential and low-frequency, high consequence events, especially involving tankers. Although most collisions result in minor consequences, the study highlights that overall risk is shaped by rare but high-consequence events, especially in environmentally sensitive areas of Baltic Sea. The findings demonstrate the importance of integrating exposure, consequence severity and operational context in maritime risk assessment and support the refinement of risk-based safety management and policy development in Swedish waters.

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  • Hebbar, Anish
    et al.
    World Maritime University, Malmö, Sweden.
    Tugume, Clever
    World Maritime University, Malmö, Sweden.
    Schröder-Hinrichs, Jens-Uwe
    World Maritime University, Malmö, Sweden.
    Vierth, Inge
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    An empirical identification of a representative case of ship grounding in Swedish waters and estimation of resultant consequences2026Report (Other academic)
    Abstract [en]

    The study examines grounding risk in Swedish waters using a multi-source, exposure-based analytical framework integrating accident data from Transportstyrelsen with operational activity data that the Swedish National Road and Transport Research Institute, VTI calculated based on HELCOM’s AIS data and supplementary environmental and economic datasets. The analysis is based on 292 grounding incidents involving passenger ships, dry cargo ships and tankers over the period 2011-2023. Grounding frequency, exposure-normalised rates and consequence profiles are assessed to identify underlying risk patterns and representative scenarios. Results show that grounding incidents are concentrated in coastal and archipelagic areas and are dominated by passenger ships, which show consistently higher grounding rates relative to distance travelled, operational time and fleet size. Dry cargo ships display lower and more stable rates, indicating grounding occurrence proportional to operational exposure. While most incidents result in minor consequences, insurance data reveal increasing claim severity over time. Tanker groundings, although rare, represent the highest potential for severe environmental and economic impact. The findings demonstrate a difference between grounding frequency and consequence severity, highlighting the limitations of relying only on absolute accident counts. By integrating exposure-based metrics with consequence analysis, the study provides a strong assessment of grounding risk. The results support the need for differentiated risk management strategies targeting high-frequency operational risks in coastal waters and preparedness for low-probability, high-impact events in environmentally sensitive regions.

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  • Odolinski, Kristofer
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Berry, Carl
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Nilsson, Jan-Eric
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Ridderstedt, Ivan
    Swedish National Road and Transport Research Institute, Society, environment and transport, Transport economics.
    Bör vi skala upp och ändra ansvar?: Analyser av stordriftsfördelar och kontrakt för järnvägsunderhåll2026Report (Other academic)
    Abstract [sv]

    Underhåll av det svenska järnvägsnätet beskrivs ofta som eftersatt och i behov av ökad finansiering. Ett komplement till ökad finansiering är att minska kostnaderna för underhåll genom effektiviseringar. I denna studie redovisas resultaten av ekonometriska analyser av ett datamaterial som omfattar uppgifter om järnvägsnätet och samhällets kostnader för järnvägsunderhåll under åren 2011–2023. Analysen pekar, för det första, på att det finns en effektiviseringspotential i att förändra kontraktens sammansättning. Genom att flytta bandelar mellan kontrakt och i förlängningen slå ihop eller dela upp kontrakt kan kostnaderna minska. En andra analys avser förekomsten av kostnadsskillnader mellan utförandeentreprenader och totalentreprenader. Eftersom avtalen har olika incitamentsstruktur och riskfördelning kan utrymmet för innovationer och därmed slutkostnader skilja sig åt. Resultaten pekar på att det kan förekomma sådana skillnader men en viss osäkerhet i resultaten gör det svårt att dra säkra slutsatser. En tredje fråga som analyseras avser nivån på den tonnagereglering som kompenserar entreprenörer för trafikökningar under avtalstiden. En jämförelse mellan underlaget för nu gällande tonnagereglering och de indikationer som ges av den nya analysen talar för att ersättningarna idag överkompenserar entreprenörerna. Sammantaget bidrar studien med empirisk kunskap som kan stödja Trafikverkets tillgångsförvaltning mot ett effektivare underhåll.

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  • Fager, Hanna
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Järlskog, Ida
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Gustafsson, Mats
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Holmberg, Benjamin
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Generation and characterization of wear particles from ferrochrome containing asphalt2026Report (Other academic)
    Abstract [en]

    Ferrochrome slag is a byproduct of high carbon ferrochrome alloy production and has promising material properties for use as aggregate in asphalt wearing courses. However, concerns remain regarding chromium-containing particle emissions during asphalt pavement wear. This study investigates the wear behaviour, particle size distribution, and elemental composition of wear particles generated from asphalt mixtures containing ferrochrome slag. Eight SMA11 and SMA16 asphalt mixtures with different combinations of slag and granite (as aggregate and filler) were prepared and tested using Tröger and Prall abrasion methods. Airborne particles were measured with Aerodynamic Particle Sizer (APS) and Scanning Mobility Particle Sizer (SMPS), and elemental composition was analysed with X-ray fluorescence (XRF).

    Prall and Tröger results show that ferrochrome slag provides wear resistance comparable to the reference material (with granite from Skärlunda as aggregate and filler), despite mixtures not being optimized for slag-specific density or porosity. All mixtures generated particles across a broad size spectrum. Tröger abrasion resulted in coarser particles due to loss of the finest particles during dry collection, while Prall testing yielded finer fractions because particles were collected in water. Airborne PM10 concentrations were similar for all mixtures, and ultrafine particles (<100 nm) were emitted regardless of aggregate type.  

    Elemental analysis of filters (total suspended fraction), collected wear particles from the Tröger apparatus (coarse fraction), and the fine fraction (PM2.5) revealed the presence of chromium in slag-containing materials. Chromium was also detected at low levels in the granite samples, likely due to abrasion of the steel needles in the Tröger apparatus. While chromium was clearly present in the generated wear particles, its oxidation state was not determined.

    Overall, the results indicate that ferrochrome slag can be used in asphalt wearing courses without increasing airborne particle emissions compared with conventional asphalt pavement. Further investigations on chromium speciation, leaching of fine fractions, and field-scale validation are recommended to ensure environmental and health safety. However, the results are based on laboratory experiments conducted under controlled conditions and although the methods are designed to simulate real studded tire wear, emissions and particle characteristics may differ under actual road conditions.

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  • Westin, Jonas
    et al.
    Transportforskningsenheten (TRUM), Institutionen för geografi; Centrum för regionalvetenskap (CERUM); Institutionen för matematik och matematisk statistik, Umeå universitet, Sverige.
    Westin, Lars
    Transportforskningsenheten (TRUM), Institutionen för geografi; Centrum för regionalvetenskap (CERUM), Umeå universitet, Sverige.
    Kristoffersson, Ida
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics. Institutionen för kommunikation, kvalitetsteknik och informationssystem, Mittuniversitetet, Sundsvall, Sverige.
    Liu, Chengxi
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    Aradóttir, Eyrún
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics. Institutionen för kommunikation, kvalitetsteknik och informationssystem, Mittuniversitetet, Sundsvall, Sverige.
    Bjurulf, Harald
    Institutionen för matematik och matematisk statistik, Umeå universitet, Sverige.
    Förutsättningar för fossilfritt regionalt flyg i norra Sverige2026Report (Other academic)
    Abstract [en]

    The ongoing industrial transformation in northern Sweden is increasing demand for labour, business services, and public services. At the same time, the region is characterised by long distances, sparsely populated areas, and a transport system with considerable variations in capacity and service levels. A central challenge is to develop transport solutions that meet this development cost-effectively and sustainably.

    This report analyses the conditions for fossil-free regional aviation within a multimodal transport system in northern Sweden. The study combines an analysis of regulations, governance and procurement with a network-based optimisation model to calculate how regional aviation networks can be designed under given technical and economic conditions. The analysis shows that aviation in Sweden today is only integrated to a limited extent in regional public transport planning. The division of responsibilities between the state and regional public transport authorities means that air traffic is managed separately from other modes of transport, hindering the development of integrated multimodal transport solutions. At the same time, a review of EU regulations suggests that there are no fundamental obstacles to including aviation in public transport systems, and that the limitations are primarily a result of how current regulations are applied in Sweden.

    Technological developments in electric and hybrid aircraft are expected to enable new forms of regional aviation in the longer term. With lower capacity and shorter range than conventional aircraft, they are suited to shorter routes, allowing for a more fine-grained network structure. Model results indicate that such systems, under certain conditions, can improve accessibility in the region and create new travel opportunities, particularly where land travel times are long.

    Range, charging infrastructure, and economic viability are also critical prerequisites for the development of future regional aviation within a multimodal transport system. The analysis shows that a transition to more direct connections between multiple regional nodes could create more travel opportunities than the current hub-and-spoke system centred on Stockholm Arlanda. Realising this potential requires greater coordination between modes of transport, including the integration of timetables, ticketing systems and physical infrastructure.

    The report identifies several key institutional barriers to this development. These include limitations on the mandate of regional public transport authorities to procure air services, insufficient use of cost-benefit analysis in the procurement of air routes, and an unclear division of responsibilities between national and regional actors. As a result, current planning is largely mode-specific rather than grounded in an overarching intermodal accessibility perspective.

    Enabling more integrated transport planning will require adapting both regulations and governance structures. Concrete proposals include strengthened regional influence over air traffic, improved methods for socioeconomic analysis of aviation's role, and enhanced coordination in planning and procurement across modes of transport.

    Fossil-free regional aviation has the potential to play an important complementary role in the future transport system of northern Sweden. The extent of its impact, however, will depend on how well it is integrated with other modes of transport within a coherent, multimodal planning framework.

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  • Nuruzzaman, Robin
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Henriksson, Malin
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Är regionförstoringen rättvis?: En analys av sydsvenska trafikförsörjningsprogram2026In: 10 år med regionala kollektivtrafikmyndigheter: perspektiv på styrning, geografi och planering i ljuset av omskalning / [ed] Ida Andersson, Örebro: Örebro universitet , 2026, p. 119-142Chapter in book (Other academic)
    Abstract [sv]

    Regionförstoring är sedan 2000-talet en central strategi för regional utvecklingspolitik och handlar om att uppmuntra och möjliggöra för människor att bo på en plats och arbeta på en annan. I det här kapitlet har vi analyserat trafikförsörjningsprogram från fem sydsvenska regioner.  Kapitlet handlar om hur syftet med regionförstoring beskrivs och vilka mål som anses kunna uppnås med hjälp av regionförstoring. Eftersom forskning visar att det finns målkonflikter mellan planeringslogikerna regionförstoring och rättvisa undersöks också hur rättvisa och sociala aspekter hanteras i programmen. 

    I kapitlet visar vi att trafikförsörjningsprogrammen uttrycker liknande idéer om vad regionförstoringen kan och bör bidra till. Urbanisering används som argument för att koncentrera satsningar till stråk där många bor och pendlar. Snabba resor mellan så kallade ”tillväxtmotorer” (större städer) framställs som avgörande för att möta framtidens behov. Kollektivtrafiken ska vara så snabb och smidig att den kan konkurrera med bilen. 

    Trots den centrala roll som hållbar utveckling spelar i RTP är de sociala dimensionerna relativt frånvarande. Trygghet och tillgänglighet för personer med funktionsnedsättning lyfts, liksom landsbygdernas särskilda behov, men frågor om exempelvis jämställdhet eller familjers vardagslogistik behandlas mer ytligt. Vi ser att dialog med medborgare har en potential när det gäller att göra planeringen mer inkluderande. 

    Regionförstoring presenteras som en lösning som skapar synergieffekter mellan tillväxt, attraktivitet och hållbarhet. Samtidigt riskerar satsningarna att förstärka geografiska och sociala skillnader. Det behövs en tydligare problematisering av hur nyttor och kostnader fördelas, samt ett arbete som integrerar social hållbarhet mer konsekvent i den strategiska kollektivtrafikplaneringen. 

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  • Hermelin, Brita
    et al.
    Centrum för kommunstrategiska studier, Institutionen för kultur och samhälle, Linköpings universitet, Sverige.
    Olsson, Christopher
    Centrum för kommunstrategiska studier, Institutionen för kultur och samhälle, Linköpings universitet, Sverige.
    Henriksson, Malin
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Kommunerna och kollektivtrafiken: roller och engagemang2026In: 10 år med regionala kollektivtrafikmyndigheter: perspektiv på styrning, geografi och planering i ljuset av omskalning / [ed] Ida Andersson, Örebro: Örebro universitet , 2026, p. 83-100Chapter in book (Other academic)
    Abstract [sv]

    Trots att de flesta län har regionaliserat huvudansvaret för kollektivtrafiken till regionala kollektivtrafikmyndigheter (RKM) visar kapitlet att kommunernas betydelse för kollektivtrafiken kvarstår efter införandet av Kollektivtrafiklagen (SFS 2010:1065). Genom deras ansvar för fysisk planering, välfärd och lokal utveckling, kopplar kommunerna kollektivtrafiken till bland annat miljömål, social inkludering, attraktivitet, landsbygdsutveckling samt tillgång till utbildning och arbetsmarknad.

    Kapitlet bygger på strukturerade intervjuer med 49 kommuner och en analys av kommunernas driftskostnader för persontransporter baserat på SCB:s räkenskapssammandrag (2024). Intervjuerna visar att kommunernas roller, inflytande och relation till RKM varierar utifrån de tre organisationsmodellerna för myndigheterna (regionalisering, hybridorganisering och kommunalförbund).

    Analysen av driftskostnaderna visar att kommuner, oavsett RKM-organisering, har utgifter kopplade till kollektivtrafiken. Kostnaderna är högre i kommunalförbund och hybridorganiseringar, vilket speglar kommunernas operativa ansvar för kollektivtrafiken. Samtidigt har nästan en femtedel av kommunerna inom regionaliserade RKM:er utgifter trots skatteväxling. Dessa kostnader rör tillköp av busslinjer, drift av hållplatser och stationer eller subventioner av busskort ofta för unga och äldre. Ett mönster är att många av dessa kommuner gränsar mot en annan region.

    Kapitlets slutsats är att föreställningen om att kommunernas roll för den allmänna kollektivtrafiken försvunnit efter lagändringen är missvisande. Styrningslandskapet präglas av ömsesidiga beroenden mellan RKM, kommuner och regioner, vilket gör dialog och koordinering avgörande för att kollektivtrafiken ska fungera som en samhällsbärande funktion.

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  • Eriksson, Linnea
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Intentionerna med kollektivtrafiklagen och dess regionala tolkningar2026In: 10 år med regionala kollektivtrafikmyndigheter: perspektiv på styrning, geografi och planering i ljuset av omskalning / [ed] Ida Andersson, Örebro: Örebro universitet , 2026, p. 29-54Chapter in book (Other academic)
    Abstract [sv]

    Den nya kollektivtrafiklagen som trädde i kraft 2012 innebar en omorganisering av ansvar, styrning och synsätt på kollektivtrafik i Sverige. Kapitlet analyserar lagstiftarens intentioner bakom lagen och jämför dessa med hur 18 regionala kollektivtrafikmyndigheter (RKM) utanför storstadsregionerna tolkar och tillämpar den. 

    Enligt lagstiftaren var lagens huvudsakliga syften att ”modernisera” kollektivtrafiklagstiftningen, anpassa den till EU:s kollektivtrafikförordning och skapa bättre förutsättningar för resenärerna. Centrala delar av lagstiftningen är definitionen av regional kollektivtrafik som vardagsresande, inrättande av regionala kollektivtrafikmyndigheter och fri etablering av kommersiell kollektivtrafik. 

    Intervjuerna med RKM visar på stora variationer i hur lagen uppfattas och tillämpas. Många beskriver att den största praktiska förändringen var organisatorisk – bolag avskaffades och nya myndigheter inrättades – medan trafikens faktiska innehåll påverkades mindre. Flera RKM tolkar lagens uppdrag som fokus på arbets- och studiependling snarare än det bredare vardagsresandet som lagstiftaren avsåg. Kommersialiseringen framstår som ett av de mest omdebatterade inslagen. Många RKM menar att lagen byggde på orealistiska antaganden om marknadens möjligheter. Sammantaget visar kapitlet att det finns glapp mellan lagstiftarens intentioner och hur lagen tolkats och tillämpats regionalt. Frågan om vad och vem kollektivtrafiken ska vara till för – och hur den ska bidra till tillgänglighet i både stad och landsbygd – framstår som central och fortsatt under förhandling. 

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  • Sørensen, Claus Hedegaard
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes.
    Lindberg, Malene Rudolf
    Mobilitet, Rum, Sted og Urbane Studier, Institut for Mennesker og Teknologi, Roskilde Universitet, Danmark.
    Delica, Kristian Nagel
    Mobilitet, Rum, Sted og Urbane Studier, Institut for Mennesker og Teknologi, Roskilde Universitet, Danmark.
    Hvordan spreder vi lokale erfaringer med grøntransport og mobilitet?2026Report (Other academic)
    Abstract [da]

    Der er er stort behov for at omstille transportsektoren, så den passer til et mere bæredygtigt samfund. Derfor foregår mange forsøg, tiltag og innovationer i kommuner, regioner, i det civile samfund og hos private virksomheder for at omstille transport og mobilitet. Noget går godt, og andet går skidt. Uanset udfaldet så foretages der næsten altid mange vigtige overvejelser og bestræbelser på at sprede erfaringer, så andre kan lære og have glæde af dem.  

    Det er temaet for denne rapport. Vi introducerer et anderledes og bredere syn på skalering, og taler om at skalere ud, op og dybt.  

    På baggrund af lokale erfaringer med otte cases fra både Danmark og Sverige i Interregprojektet Green Mobility Shift i 2023-2026 illustrerer vi, hvordan man kan arbejde med at skalere ud, op og dybt, hvilke problemer man kan støde på, og vi peger på vigtige forudsætninger for at lykkes. 

    At skalere ud vil sige at sprede en idé eller en innovation i geografisk eller i det sociale - altså sprede til flere steder eller til flere målgrupper. Det er den dimension af skalering, som man oftest har fokus på, og som ofte betegnes som at skalere op.   

    At skalere op indebærer her at ændre systemer og strukturer – fx lovgivning, politik eller institutioner – for at understøtte idéer eller innovationer.   

    At skalere dybt indebærer at påvirke kulturelle værdier, relationer og tankesæt – altså opnå en dybere social transformation eller en fælles læring. Her ændres fx organisationsstrukturer, ansatte opkvalificeres, normer i befolkningen ændres m.m.

    De tre former for at skalere påvirker hinanden, og effektiv skalering kræver en kombination af de tre dimensioner.

    Vi konkluderer i syv punkter: 

    • Man fejler ikke, hvis man ikke formår at skalere ud.
    • Det tager tid at skalere, når det handler om at påvirke mobilitetsvaner.
    • Vedholdenhed er afgørende for den, som vil skalere ud, op eller dybt.
    • Nye partnere er ofte vigtige for at skalere. De kan skabe broer til andre kontekster. 
    • Lokal tilpasning er nødvendigt for at skalere ud til andre kontekster.  T
    • iming, politiske agendaer og mulighedsvinduer er afgørende for at skalere op.
    • Borgernes deltagelse kan være afgørende for at skalere dybt.

    Det er vigtigt at arbejde med at skalere (små) lokale erfaringer, så omstillingen af transportsektoren styrkes. Formår man succesfuldt at skalere på alle tre dimensioner, skabes potentielt en stor kraft, som kan give et stort bidrag til omstillingen. 

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  • Bjurström, Henrik
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Bratu, Claudia
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Egeskog, Johan
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Tankbeläggningar: Långtidsuppföljning och kravställning2026Report (Other academic)
    Abstract [sv]

    I denna rapport sammanställs resultat från långtidsuppföljning av 47 tankbeläggningar utförda mellan 2003 och 2024. De tankbeläggningar som har studerats består av ytbehandlingar (Y1B, Y2B och Racked-in) och indränkt makadam (IM, IMT, JIM och JIMT). Syftet är att öka kunskapen om hur olika typer av tankbeläggningar presterar över tid, och att ge rekommendationer för framtida kravställning.  

    Tillståndsutveckling för uppföljda objekt har analyserats utifrån längsgående ojämnhet (IRI), makrotextur (MPD) och spårdjup. Resultaten visar att IRI- och spårdjupsutvecklingen generellt varierar lite mellan beläggningstyperna, medan utvecklingen av makrotexturen uppvisar stora skillnader. Y1B har hög initial textur som minskar snabbt de första åren, medan Racked-in ger lägre initial textur och når lägre nivåer snabbare, vilket ger bättre energieffektivitet med avseende på bränsleförbrukning. Indränkt makadam har lägst initial textur och en minskande texturutveckling som är långsammare än ytbehandlingarnas. Mätdata jämförd med prognosvärden från kontrollgrupper har inte en tydlig överensstämmelse och vissa objekt frångår prognosvärdena med stora marginaler, både på grund av bättre och sämre utveckling än prognos.

    Kravställningen för ytbehandlingar är mer utförlig jämfört med indränkt makadam, som saknar krav på maximalt tillåtna defekter och makrotextur. Det föreslås att homogenisera kraven mellan olika tankbeläggningar för att säkerställa liknande kvalitet, antingen genom att utöka kraven på indränkt makadam eller genom att ställa olika krav på tankbeläggningar baserat på vägens ÅDT. 

    Rapporten diskuterar vikten av bättre dokumentation av utförande och hur materialvalet påverkar beläggningens livslängd. Exempel från två ytbeläggningar illustrerar hur skillnader i stenmaterial, läggningstidpunkt och typ av trafikflöde påverkar resultatet kraftigt. 

    Tankbeläggningar har potential att bidra till minskad klimatpåverkan, men mer detaljerad forskning kring olika komponenters utsläppsbidrag och framtagande av uppdaterade emissionssiffror behövs för att avgöra hur olika beläggningar står sig mot varandra och hur processen kan optimeras. Vidare forskning behövs även för att förstå vilka förhållanden under läggning som ger tankbeläggningar med god beständighet. 

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  • Kuttah, Dina K
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Influence of a lignosulfonate-based additive on the deformation characteristics of a Swedish-designed gravel wearing course2026In: WASCON 2026: The 12th International Conference on the Environmental and Technical Implications of Construction with Alternative Materials : E-proceedings, 2026, p. 221-224Conference paper (Other academic)
    Abstract [en]

    Gravel wearing courses (GWC) on unpaved roads are exposed to traffic and severe climate, including freeze–thaw and repeated wetting–drying, which can lead to rutting, surface degradation and increased maintenance needs. Chemical stabilization is one way to improve performance, and lignosulfonate products are of special interest because they are bio-based binders already used as dust suppressants on gravel roads. Lignin is contained in the cell walls of plants and obtained as a byproduct of the paper and lignocellulosic industries (Misra et al., 2011). Lignin, representing the third largest fraction of plant biomass, is a large complex polymer of phenylpropane and methoxy groups, a noncarbohydrate polyphenolic substance that encrusts plant cell walls and cements plant cells together (Kim et. al., 2012). Most lignin-based industrial products in the forms of binder, dispersant, emulsifier, and sequestrant are derived from sulfite lignin (International Lignin Institute, 2008). Since lignosulphonates are by-products of other processes, they are relatively inexpensive and usually used as a dust control agent during gravel roads maintenance. This paper summarizes the behaviour of a lignin-based stabilizer, Listab, in comparison with an unstabilized reference GWC, based on a laboratory study in which both mixtures were tested under controlled freeze–thaw cycles (FTCs) and soaking–drying cycles (SDCs) using a laboratory light weight deflectometer (LWD).

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  • Wallhagen, Susanne
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Driver and vehicle.
    Forsman, Åsa
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Lagstiftning om elsparkcyklar: Vad kan Sverige lära av Danmark, Norge och Finland?2026Report (Other academic)
    Abstract [en]

    Electric scooters, both rented and privately owned, have become a common feature in the Swedish traffic environment after 2018. The vehicle is classified as a bicycle and the number of electric scooter crashes, where someone was injured, has increased sharply and was about 4,700 in 2024. 

    The aim of the project was to study the regulations governing electric scooters and their use in Denmark, Norway and Finland, as well as how and why these regulations came about. This knowledge can be used as a basis for discussing Sweden's regulations, which differ from the other countries. 

    The project is based on material available via the websites of authorities and other organizations, as well as information that we obtained through email exchanges and interviews.  

    The results show that the electric scooter is classified as a small electric motor vehicle in the other countries. Even so, it is often to be used according to bicycle regulations. Other differences from Sweden's rules are that there is an age limit for riding an electric scooter (12 years in Norway, 15 years in Denmark and Finland) and a drink-driving law equivalent to that of other motor vehicles. In Norway, helmets are required for children under 15 years of age, in Denmark for all ages, and in Finland it is a strong recommendation for everyone to use a helmet. 

    Finally, we note that it is impossible to determine which of the countries has been most successful in reducing the number of injuries with electric scooters through its regulations. This is due to the difficulties obtaining comparative figures both in terms of injuries and exposure. However, Denmark has increased helmet use, especially on privately owned electric scooters, and Norway has reduced the proportion of injuries in accidents where the driver was influenced by alcohol or other drugs. 

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  • Dinegdae, Yared
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Design criteria for ERAPave PP2026Report (Other academic)
    Abstract [en]

    Design or failure criteria are an integral part of any pavement design procedure. They represent the allowable thresholds beyond which a pavement is no longer expected to effectively perform its intended functions. It is crucial to establish appropriate design criteria for pavement failure modes, as these criteria govern long-term technical, functional, economic and safety performance.

    This report aims to establish design criteria for the failure modes incorporated in ERAPave PP (Elastic Response Analysis of PAVEments – Performance Prediction). This is achieved by combining a qualitative literature survey with a quantitative methodology that systematically assesses the performance, maintenance and rehabilitation (M&R) intervention histories of Swedish sections. The literature survey, which aimed to identify existing challenges and experiences, was conducted with a focus on pavement design methods, distresses and design criteria. In the quantitative study, annual distress measurements and M&R intervention timings were evaluated and modelled using various mathematical functions to establish representative average accumulation rates. 

    The findings have shown that the selection of pavement design criteria requires the consideration of multiple factors, including technical, economic, safety and user expectations. In addition, the subjective nature of these criteria and the use of multiple thresholds for the same distress have limited their application and impact. The quantitative study showed inconsistency in M&R interventions and high variability in measured distresses. Nevertheless, it is possible to establish design criteria for the rutting and fatigue cracking failure modes in ERAPave PP, as well as for surface roughness, by modelling distress accumulation with a directly proportional linear function. It is important to further enhance estimated values using a multi-objective optimization function that considers all relevant factors and performance data from a wide range of pavements.  

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  • Howard, Christian
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Forsman, Åsa
    Swedish National Road and Transport Research Institute, Traffic and road users, Traffic Safety and Traffic System.
    Datakvalitet i Transportstyrelsens register över vägtrafikolyckor (Strada): En beskrivning ur ett användarperspektiv2026Report (Other academic)
    Abstract [en]

    Strada is a national registry for road traffic crashes that combines data from the police and emergency hospitals. The aim is to provide detailed information on both crash circumstances and injuries for research, evaluation, and target monitoring. 

    The purpose of this study is to describe Strada’s data quality from a user perspective and to propose recommendations for improving quality and usability. Partial missing data, report matching, data linkages to the national road database (NVDB), documentation and metadata are explored. The study is based on analysis of Strada data, document studies, and the collection of expert knowledge. 

    The results show that the coverage of fatalities is insufficient, the usability of linked NVDB data is low, and documentation needs improvement. Regarding partial missing data, the results indicate an improvement over time for police reports and a decline for healthcare reports. Furthermore, a description of the matching algorithm has been developed. Based on this description and the results, it is recommended to  

    1. hold discussions with the ministry and the relevant authorities concerning police deprioritisation of reporting to Strada 
    2. prioritise inclusion of individuals with protected personal data 
    3. expand the value sets of variables to provide clearer categorisation of missing values 
    4. ensure possible linkage to the police’s internal investigation materials 
    5. map the matching algorithm in detail 
    6. develop a user guide describing the linkage to NVDB 
    7. reintroduce road type as a police-reported variable with the NVDB value set 
    8. develop the reporting tools to only include relevant road links from NVDB and to structure them into separate variables 
    9. divide the user manual into two documents with registry information and extraction information 
    10. create a machine-readable variable metadata file to be included with extracted data, and 
    11. offer data in text format as an alternative to the Excel format.
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  • Hieronymus, Magnus
    et al.
    Oceanographic Research Unit, Swedish Meteorological and Hydrological Institute, Norrköping, Sweden.
    Hedfors, Jim
    Swedish Geotechnical Institute, Linköping, Sweden.
    Van Well, Lisa
    Swedish Geotechnical Institute, Linköping, Sweden.
    Göransson, Gunnel
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Bokhari Irminger, Sebastian
    Swedish Geotechnical Institute, Linköping, Sweden.
    Magnusson, Åke
    Swedish Geotechnical Institute, Linköping, Sweden.
    Estimating the cost of sea level rise2026In: Marine Development, E-ISSN 3004-832X, Vol. 4, no 1, article id 9Article in journal (Refereed)
    Abstract [en]

    Sea level rise exacerbates flood risk for coastal communities globally. Multiple studies have shown that significant property values are already at risk this century, especially in high-emission scenarios. Thus, sea level rise poses major challenges that cannot be effectively addressed by many existing flood risk management methods. Some challenges include managing uncertainties, time dependence, and the interplay between mean sea level rise and extremes. Here, these components are integrated into a joint probabilistic framework, with the novelty of the approach being the direct connection of these factors to economic risk. The resulting framework provides a probabilistic assessment of flooding loss conditioned on user-defined emission scenario probabilities. The framework fits well as a tool for risk assessment, uncertainty quantification, and decision support. A major takeaway is that the risk increase accelerates with warming. Another takeaway is that the objectivity of flood risk assessments decreases significantly with increasing assessment length, with flood risk becoming more dependent on mean sea level change. The framework requires only readily available data and an open source model, enabling better-informed risk assessments through improved data utilization. The framework is validated using data from Kalmar city, one of Sweden’s oldest cities, located in the south and known for its rich cultural heritage. 

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  • Göransson Scalzotto, Joel
    Swedish National Road and Transport Research Institute, Society, environment and transport, Mobility, actors and planning processes. Department of Urban Planning and Environment, KTH Royal Institute of Technology, Stockholm, Sweden.
    Fueling the backlash: The Fuel Uproar 2.0 and the political re-articulation of legitimacy in Swedish climate politics2026In: Geoforum, ISSN 0016-7185, E-ISSN 1872-9398, Vol. 174, article id 104700Article in journal (Refereed)
    Abstract [en]

    Popular backlashes against decarbonization transitions have attracted growing attention from scholars and policymakers alike. This article examines the articulation of backlash politics in Swedish climate governance through the lens of post-foundational political theory, drawing primarily on Laclau and Mouffe’s writings on hegemony, articulation, and empty signifiers. Focusing on the digital protest movement “The Fuel Uproar 2.0″ and the subsequent policy reversals in Swedish fuel politics following the 2022 election, the article traces how heterogeneous grievances were condensed into a chain of equivalence centered on the fossil fuel car as a nodal point, and how this articulation contributed to a broader rearticulation of legitimacy in Swedish climate politics. Rather than functioning as a delegitimating force alone, the Fuel Uproar contributed to the production of new legitimacies, in which popular acceptance has increasingly become a precondition for, rather than an outcome of, climate policy. A central reflection is that populist mobilization and technocratic, market-oriented climate governance have operated not as opposing political projects but as complementary fronts within a shared hegemonic formation, a dynamic that sits uneasily with orthodox theoretical interpretations of the relationship between populism and technocracy. 

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  • Fors, Carina
    et al.
    Swedish National Road and Transport Research Institute, Traffic and road users, The Human in the Transport system..
    Fager, Hanna
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Hafting, Morten
    Ramboll, Norge.
    Nordic certification system for road marking materials: Version 11:20262026Report (Other academic)
    Abstract [en]

    A Nordic certification system for road marking materials was introduced in 2015. The system is based on documented performance measurements of material samples applied on test fields on public roads. The certification system includes both flat (type I) and structured/profiled (type II) markings, antiskid materials (materials with enhanced friction), temporary markings, inlaid markings (Norway only), materials for hand application and materials with enhanced durability for illuminated high-traffic urban areas. 

    Material tests are carried out at two test sites: one in Norway and one in Denmark. The test fields are situated on public roads and the tested materials are thus exposed to real traffic conditions and to weather conditions representative for the Nordic countries. The materials are followed up by performance measurements for one or two years. The certification includes requirements on coefficient of retroreflected luminance RL under dry and wet conditions, luminance coefficient under diffuse illumination Qd, friction and chromaticity coordinates. The number of wheel passages is measured at the test sites annually. The certification system includes material identification, to verify that the manufacturer’s declaration of constituents agrees with the material applied on the test field.  

    The certification system is based on the European standards EN 1824 Road marking materials – Road trials, EN 1436 Road marking materials – Road marking performance for road users, EN 12802 Road marking materials – Laboratory methods for identification, and EN 13212 Road marking materials – Requirements for factory production control

    This document constitutes the guidelines for the Nordic certification system. The document describes the certification procedure, what type of products that are included in the system and the requirements for certification. Furthermore, the procedures and methods used for application of materials, performance measurement and identification analysis are described. The document also gives specifications and practical information regarding the test sites and regarding registration and application of products for certification. 

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  • Klar, Robert
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics. Communications and Transport Systems, Department of Science and Technology, Linköping University, Sweden.
    Andersson, Anders
    Swedish National Road and Transport Research Institute, Traffic and road users, Vehicle Systems and Driving Simulation..
    Angelakis, Vangelis
    Communications and Transport Systems, Department of Science and Technology, Linköping University, Sweden.
    Understanding and predicting quay crane breakdowns using explainable AI2026In: Maritime Transport Research, ISSN 2666-822X, Vol. 10, article id 100152Article in journal (Refereed)
    Abstract [en]

    Quay cranes (QCs) play a vital role in ship-to-shore operations, enabling the seamless transfer of cargo between sea and land. However, increasing trade volumes require faster and more cost-effective container handling, exerting significant pressure on QCs and leading to greater wear on critical components such as wires, hoists, and rope clamps. While operations research has explored maintenance scheduling to improve terminal performance, comparatively little work has examined how machine learning can exploit the growing volume of QC monitoring and operational data to predict breakdowns before they occur. This study contributes to this area by integrating terminal operations data, QC monitoring logs, and meteorological observations into a unified analytical framework. We employ explainable artificial intelligence (XAI), using both global and local SHapley Additive exPlanations (SHAP) to identify the operational and environmental factors most strongly associated with QC failures and to illustrate concrete, instance-level examples of how specific conditions contribute towards breakdowns. In parallel, we develop a robust machine learning pipeline built around nested cross-validation to assess the predictive capability of multiple classifiers for forecasting QC breakdowns. Our XAI analysis reveals that breakdown risk is closely linked to QC working time, the distribution of moves across simultaneously operating QCs, hoist overload and trolley alignment warnings, and adverse weather conditions. Among the evaluated models, LightGBM achieved the highest predictive accuracy, reaching up to 83% in identifying breakdown-prone scenarios. These findings demonstrate the feasibility and value of data-driven predictive maintenance for QCs, providing insights that support safer, more reliable, and more efficient terminal operations. 

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  • Arvidsson, Niklas
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    Klar, Robert
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics. Communications and Transport Systems, Department of Science and Technology, Linköping University, Sweden.
    Stelling, Petra
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    Svensson, Nina
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Electrifying Island Ferries: Insights from Interviews and Explainable AI2026Conference paper (Refereed)
    Abstract [en]

    Electrification is seen as a key pathway toward more sustainable transport systems. This paper examines a Swedish island ferry conversion from diesel to battery electric propulsion by integrating quantitative and qualitative insights: (i) a route-level efficiency assessment to map energy savings across comparable service legs; (ii) an explainable gradient boosting model (SHAP) to quantify the operational and environmental drivers of trip-level energy use; and (iii) interviews with 55 passengers and three captains to capture perceived benefits, operational constraints, and adaptation strategies. The model achieves high predictive accuracy (R2 = 0.97), showing that vessel speed and propulsion type dominate variation in energy intensity, while route geometry and wind contribute smaller but systematic effects. Electrification reduces energy intensity across routes by 10-87%, driven primarily by higher conversion efficiency. Interview results reveal improved onboard comfort, tighter operational margins around charging and schedule adherence, and heating loads as critical constraints in colder seasons. The combined use of EMS data, interpretable ML, and stakeholder interviews provides a rare, system-level perspective on the technical and human factors shaping electric ferry performance. Viewed through a multi level perspective, the findings indicate that electric ferries scale most effectively on short, predictable routes when infrastructure, timetables, and procurement incentives align with the operational characteristics of electric propulsion.

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  • Klar, Robert
    et al.
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics. Communications and Transport Systems, Department of Science and Technology, Linköping University, Sweden.
    Svensson, Nina
    Swedish National Road and Transport Research Institute, Society, environment and transport, Environment.
    Stelling, Petra
    Swedish National Road and Transport Research Institute, Society, environment and transport, Traffic analysis and logistics.
    Angelakis, Vangelis
    Communications and Transport Systems, Department of Science and Technology, Linköping University, Sweden.
    Fuel efficiency in ferry services: GPS-based clustering and explainable AI2026In: Transportation Research Part D: Transport and Environment, ISSN 1361-9209, E-ISSN 1879-2340, Vol. 157, article id 105403Article in journal (Refereed)
    Abstract [en]

    Enhancing fuel efficiency in ferry operations is essential for reducing emissions and advancing maritime sustainability. This study presents a data-driven framework that uses second-level GPS data enriched with operational and environmental variables to identify and explain fuel consumption patterns. Vessel movements are segmented into trip legs and journeys, and operational metrics such as speed, wind exposure, and fuel use are computed. A hybrid machine learning approach combines unsupervised clustering to detect recurring operational patterns with gradient boosting models and explainable methods to quantify feature impacts. The framework achieves strong performance, with a cluster classification accuracy of 94 percent and a coefficient of determination of 0.97 for fuel prediction. Results indicate that operational speed is the dominant driver of fuel consumption, while analysis of captain assignments reveals the influence of human factors. The proposed framework provides actionable insights for speed management and operational optimization, enabling cost-effective emission reductions in ferry services.  

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