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Liu, D., Wang, C., Gonzalez-Libreros, J., Andersson, A., Elfgren, L. & Sas, G. (2026). Machine learning-driven investigation of environmental effects on dynamic behavior of railway noise barriers based on long-term field test. Engineering structures, 348, Article ID 121812.
Open this publication in new window or tab >>Machine learning-driven investigation of environmental effects on dynamic behavior of railway noise barriers based on long-term field test
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2026 (English)In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 348, article id 121812Article in journal (Refereed) Published
Abstract [en]

The passage of trains by railway noise barriers induces vibrations that may affect their fatigue performance and reduce their service life. However, long-term field monitoring of noise barriers under complex environmental and operation conditions remains rare. This study develops an interpretable machine learning (ML) framework to investigate the aerodynamic pressure and dynamic behaviors of noise barriers based on a nine-month long-term field monitoring campaign, yielding 12810 train runs over 105 valid days. Input variables include train type, speed, temperature, wind speed and direction, relative humidity, and air pressure, while the target responses cover train-induced aerodynamic pressure, stress near the base of the steel post, and displacement at the post top. Eight ML models, including four traditional and four ensemble algorithms, were used and systematically compared to evaluate their predictive capabilities and robustness. Ensemble models, particularly Gradient Boosting Decision Tree (GBDT), Light Gradient Boosting Machine (LGBM), and Extreme Gradient Boosting (XGBoost), achieved the best predictive performance, with R2 values exceeding 0.935 for stress and displacement, and 0.895 for pressure. XGBoost, offering a strong balance of predictive accuracy and computational efficiency, was selected for SHapley Additive exPlanations (SHAP)-based interpretability analysis to uncover the physical relationships behind the data-driven predictions. Results reveal that aerodynamic pressure was the most challenging response to predict, given its higher sensitivity to turbulent airflow and environmental fluctuations, whereas stress and displacement exhibited more stable and predictable patterns. SHAP analysis identified train speed and type as the most influential factors across all responses. While environmental factors had comparatively lower influence, temperature and instantaneous wind direction consistently showed higher importance among them. Relative humidity has a moderate effect on aerodynamic pressure but a minor impact on dynamic behavior. Air pressure and wind speed exhibit limited influence on all outputs. These findings highlight the novelty and effectiveness of integrating long-term monitoring data, ML methods, and SHAP-based interpretability, offering new insights into the dynamic behavior of railway noise barriers.

Place, publisher, year, edition, pages
Elsevier, 2026
Keywords
Aerodynamic pressure, Dynamic behavior, Environmental influence, Long-term field monitoring, Machine learning, Railway noise barrier, SHAP analysis
National Category
Vehicle and Aerospace Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-115616 (URN)10.1016/j.engstruct.2025.121812 (DOI)
Funder
Swedish Transport Administration, BBT-2019-022, BBT-2024-031Svenska Byggbranschens Utvecklingsfond (SBUF), 14486
Note

Validerad;2025;Nivå 2;2025-12-01 (u5);

Full text license: CC BY 4.0

Available from: 2025-12-01 Created: 2025-12-01 Last updated: 2025-12-01Bibliographically approved
Liu, D., Wang, C., Gonzalez-Libreros, J., Tu, Y., Elfgren, L. & Sas, G. (2025). Comprehensive model for train-induced aerodynamic pressure on noise barriers: effects of bilateral layout and height. Engineering Applications of Computational Fluid Mechanics, 19(1), Article ID 2471296.
Open this publication in new window or tab >>Comprehensive model for train-induced aerodynamic pressure on noise barriers: effects of bilateral layout and height
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2025 (English)In: Engineering Applications of Computational Fluid Mechanics, ISSN 1994-2060, E-ISSN 1997-003X, Vol. 19, no 1, article id 2471296Article in journal (Refereed) Published
Abstract [en]

Noise barriers play a crucial role in mitigating railway noise, with the aerodynamic pressure exerted by passing trains being a key factor in their structural design, particularly for those installed along high-speed railways. While previous studies have focused on the effects of train speed, geometry, and distance from the track centre, and have developed models incorporating these factors, limited attention has been given to the impact of bilateral layouts and barrier height on this pressure. Quantitative assessments of these two factors remain scarce, and existing pressure calculation models inadequately address their influence. This study addressed these gaps by employing computational fluid dynamics (CFD) simulations, validated by field test data, to qualitatively and quantitatively analyze the effects of barrier layout and height on the aerodynamic pressure acting on vertical noise barriers. The results demonstrate that two distinct transient pressure fluctuations over time are generated by the train’s nose and tail, in agreement with the findings of the field tests. A bilateral layout increases peak pressure by up to 8.5%, particularly as the distance to the train centreline decreases. Moreover, increasing barrier height from 2 to 4 m resulted in a maximum pressure amplification of 13.23%, though the amplification rate diminished with further height increases. To address the limitations of existing pressure calculation models, an exponential model was developed to account for the amplification effect of bilateral layouts, while a logarithmic correction factor was introduced to account for barrier height. These models were integrated into a comprehensive aerodynamic pressure calculation framework, effectively capturing the combined impacts of barrier layout and height. Validated through simulations, the proposed model offers a more accurate and practical approach for predicting train-induced aerodynamic pressure on noise barriers, providing valuable insights to inform their structural design.

Place, publisher, year, edition, pages
Taylor & Francis, 2025
Keywords
Aerodynamic pressure, barrier height, bilateral layout, computational fluid dynamics simulation, pressure model, railway noise barrier
National Category
Fluid Mechanics
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-111974 (URN)10.1080/19942060.2025.2471296 (DOI)001434013100001 ()2-s2.0-105000535108 (Scopus ID)
Funder
Swedish Transport Administration, BBT-2019-022 and No. BBT-TRV 2024/132497
Note

Validerad;2025;Nivå 2;2025-04-09 (u2);

Full text license: CC BY;

Available from: 2025-03-11 Created: 2025-03-11 Last updated: 2025-10-21Bibliographically approved
Liu, D., Wang, C., Gonzalez-Libreros, J., Andersson, A., Elfgren, L. & Sas, G. (2025). Dynamic behavior of steel post/wood panel railway noise barriers under aerodynamic loads induced by high-speed trains. Railway Engineering Science
Open this publication in new window or tab >>Dynamic behavior of steel post/wood panel railway noise barriers under aerodynamic loads induced by high-speed trains
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2025 (English)In: Railway Engineering Science, ISSN 2662-4745Article in journal (Refereed) Epub ahead of print
Abstract [en]

Railway noise barriers are an essential piece of infrastructure for reducing noise propagation. However, these barriers experience aerodynamic loads generated by high-speed trains, leading to dynamic effects that may compromise their fatigue capacity. The most common structural design for railway noise barriers consists of vertical configurations of posts and panels. However, there have been few dynamic analyses of steel post/wood panel noise barriers under train-induced aerodynamic loads. This study used dynamic finite element analysis to assess the dynamic behavior of such noise barriers. Analysis of a 40-m-long noise barrier model and a triangular simplified load model, the latter of which effectively represented the detailed aerodynamic load, were first used to establish the model and input of the moving load during dynamic simulation. Then, the effects of different parameters on the dynamic response of the noise barrier were evaluated, including the damping ratio, the profile of the steel post, the span length of the panel, the barrier height, and the train speed. Gray relational analysis indicated that barrier height exhibited the highest correlations with the dynamic responses, followed by train speed, post profile, span length, and damping ratio. A reduction in the natural frequency and an increase in the train speed result in a higher peak response and more pronounced fluctuations between the nose and tail waves. The dynamic amplification factor (DAF) was found to be related to both the natural frequency and train speed. A model was proposed showing that the DAF significantly increases as the square of the natural frequency decreases and the cube of the train speed rises.

Place, publisher, year, edition, pages
Springer Nature, 2025
Keywords
Aerodynamic load, Dynamic amplifcation factor, Dynamic behavior, Finite element analysis, High-speed train, Railway noise barrier
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-112214 (URN)10.1007/s40534-025-00377-5 (DOI)001448881100001 ()2-s2.0-105000502708 (Scopus ID)
Funder
Swedish Transport Administration, BBT-2019-022Swedish Transport Administration, BBT-TRV 2024/132497
Note

Full text license: CC BY 4.0;

Available from: 2025-04-02 Created: 2025-04-02 Last updated: 2025-10-21
Liu, D., Wang, C., Gonzalez-Libreros, J., Tu, Y., Elfgren, L., Sas, G., . . . Höjsten, T. (2024). FEM-based dynamic analysis of noise barriers under train-induced aerodynamic load. In: J S Jensen; D Frangopol; J W Schmidt (Ed.), Bridge Maintenance, Safety, Management and Sustainability: . Paper presented at 12th International Conference on Bridge Maintenance, Safety and Management (IABMAS 2024), Copenhagen, Denmark, June 24-28, 2024 (pp. 3817-3824). CRC Press
Open this publication in new window or tab >>FEM-based dynamic analysis of noise barriers under train-induced aerodynamic load
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2024 (English)In: Bridge Maintenance, Safety, Management and Sustainability / [ed] J S Jensen; D Frangopol; J W Schmidt, CRC Press, 2024, p. 3817-3824Conference paper, Published paper (Refereed)
Abstract [en]

Railway noise barriers should provide excellent sound insulation and sufficient load-bearing capacity. High-speed railway noise barriers experience significant and transient aerodynamic loads from passing trains, resulting in noticeable dynamic responses. In this study, three simplified load models were applied to a noise barrier to compare the dynamic responses to those obtained under a reference load from computational fluid dynamics (CFD) simulations, Results show that the natural frequency of target noise barriers exceeds 10 Hz, significantly surpassing the excitation frequency of the train-induced areodynamic load, thereby minimizing the likelhood of resonance. The displacement or stress evolution closely correlatesd with the variation of pressure over time. Along the longitudinal direction of the noise barrier, the stress range initially increases, stabilizes, and eventually decreases, reaching its maximum at the penultimate post. Compared to the two simplified rectangular load models, the triangular load model with a distribution load length of 12 m better represents the detailed time-varying aerodynamic load.

Place, publisher, year, edition, pages
CRC Press, 2024
Keywords
Noise barriers, Train-induced aerodynamic load, Dynamic analysis
National Category
Fluid Mechanics
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-108354 (URN)10.1201/9781003483755-450 (DOI)2-s2.0-85200421298 (Scopus ID)
Conference
12th International Conference on Bridge Maintenance, Safety and Management (IABMAS 2024), Copenhagen, Denmark, June 24-28, 2024
Funder
Swedish Transport Administration, BBT-2019-022
Note

Full text license: CC BY-NC-ND;

ISBN for host publication: 978-1-032-77040-6, 978-1-032-77560-9, 978-1-003-48375-5 

Available from: 2024-07-18 Created: 2024-07-18 Last updated: 2025-10-21Bibliographically approved
Liu, D., Wang, C., Gonzalez-Libreros, J., Tu, Y., Elfgren, L. & Sas, G. (2024). Modified calculation model of train-induced aerodynamic pressure on vertical noise barriers considering the train geometry effect. Journal of Wind Engineering and Industrial Aerodynamics, 249, Article ID 105750.
Open this publication in new window or tab >>Modified calculation model of train-induced aerodynamic pressure on vertical noise barriers considering the train geometry effect
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2024 (English)In: Journal of Wind Engineering and Industrial Aerodynamics, ISSN 0167-6105, E-ISSN 1872-8197, Vol. 249, article id 105750Article in journal (Refereed) Published
Abstract [en]

High-speed trains (HSTs) generate air disturbance, leading to significant aerodynamic pressure on the noise barriers. Differences in train geometry result in variations in the aerodynamic pressure on noise barriers, implying that existing European standard calculation models may not necessarily be suitable for all types of HSTs. In this paper, the influence of the width, height, and nose length of the train on the aerodynamic pressure on vertical noise barriers was studied using computational fluid dynamics (CFD) simulations. Results showed that taller and wider trains result in greater aerodynamic loads on noise barriers. Conversely, an increase in the nose length of a train leads to a reduction in such pressure. Using grey relational analysis, correlation of various factors with the train-induced aerodynamic pressure is, from strong to weak: distance to the track center, width, height, and nose length of the train. Building upon the EN 14067-4 calculation model, the shape coefficients of trains with varying geometric characteristics were derived using the simulation data obtained in this study. A modified pressure calculation model was established accounting for the differences in geometric features of HSTs and pressure distribution in the vertical direction of noise barriers and validated using relevant data from the literature.

Place, publisher, year, edition, pages
Elsevier, 2024
Keywords
Aerodynamic pressure, Computational fluid dynamics simulation, Pressure calculation model, Train geometry, Vertical noise barrier
National Category
Fluid Mechanics
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-101567 (URN)10.1016/j.jweia.2024.105750 (DOI)001289120300001 ()2-s2.0-85191294975 (Scopus ID)
Funder
Swedish Transport Administration, BBT-2019-022
Note

Validerad;2024;Nivå 2;2024-06-28 (joosat);

Full text: CC BY License

Available from: 2023-10-04 Created: 2023-10-04 Last updated: 2025-10-21Bibliographically approved
Jin, J., Liu, D. & Tu, Y. (2024). Numerical Simulation of Aerodynamic Pressure on Sound Barriers from High-Speed Trains with Different Nose Lengths. Applied Sciences, 14(7), Article ID 2898.
Open this publication in new window or tab >>Numerical Simulation of Aerodynamic Pressure on Sound Barriers from High-Speed Trains with Different Nose Lengths
2024 (English)In: Applied Sciences, E-ISSN 2076-3417, Vol. 14, no 7, article id 2898Article in journal (Refereed) Published
Abstract [en]

For high-speed railway sound barriers, determining the aerodynamic pressure generated by high-speed trains is crucial for their structural design. This paper investigates the distribution of aerodynamic pressure on the sound barrier caused by high-speed trains with different nose lengths, utilizing the computational fluid dynamics (CFD) simulation method. The accuracy of the numerical simulation method employed is verified through comparison with field test results from the literature. Research findings reveal that when a high-speed train passes through a sound barrier, significant “head wave” and “wake wave” effects occur, with the pressure peak of the “head wave” being notably greater than that of the “wake wave”. As the distance between the sound barrier and the center of the train gradually increases, the aerodynamic pressure on the sound barrier gradually decreases. The nose length of the train has a considerable impact on the aerodynamic pressure exerted on the sound barrier. The streamlined shape of longer-nose trains can significantly reduce the aerodynamic effects on the sound barrier, resulting in a notably smaller pressure peak compared to shorter-nose trains. Finally, by establishing the relationship between the train nose length and the aerodynamic pressure peak, a calculation formula for the train-induced aerodynamic pressure acting on the sound barrier is proposed, taking into account the nose length of the high-speed train.

Place, publisher, year, edition, pages
MDPI, 2024
Keywords
aerodynamic pressure, sound barrier, high-speed trains, fluid dynamics, numerical simulation, nose length of high-speed train
National Category
Fluid Mechanics Energy Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-105172 (URN)10.3390/app14072898 (DOI)001200850500001 ()2-s2.0-85192518675 (Scopus ID)
Note

Validerad;2024;Nivå 2;2024-04-23 (signyg);

Funder: Natural Science Foundation of China (51378104); Jiangsu Province (BZ2021011); Fundamental Research Funds for the Central Universities (2242022k30030, 2242022k30031);

Full text license: CC BY 4.0

Available from: 2024-04-22 Created: 2024-04-22 Last updated: 2025-10-21Bibliographically approved
Liu, D., Wang, C., Gonzalez, J., Enoksson, O., Höjsten, T., Tu, Y., . . . Sas, G. (2024). Numerical simulation of train-induced aerodynamic pressure on railway noise barriers. In: Dynamics of railway infrastructures: . Paper presented at XII International Conference on Structural Dynamics, Delft, Netherlands, July 2-5, 2023.. Institute of Physics Publishing (IOPP), 10, Article ID 102002.
Open this publication in new window or tab >>Numerical simulation of train-induced aerodynamic pressure on railway noise barriers
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2024 (English)In: Dynamics of railway infrastructures, Institute of Physics Publishing (IOPP), 2024, Vol. 10, article id 102002Conference paper, Published paper (Refereed)
Abstract [en]

Noise barriers built parallel to the railway to reduce noise pollution, will be subjected to strong aerodynamic pressure from high-speed trains and have significant dynamic responses under such pressure. Based on computational fluid dynamics (CFD), a numerical simulation of train-induce aerodynamic pressure on noise barriers was performed. Time-varying pressure and its distribution along height direction of noise barriers were analysed, and the effect of different factors on results, i.e., the distance from noise barriers to track centre and the height of noise barrier, were discussed. Results show that the geometric changes in train nose and tail cause the obvious transient pressure pulse, and the pressure magnitude from nose is higher than that from tail. When the measuring height increases, the pressure gradually decreases, which can be well characterized by a height coefficient equation from Germany DB code. The pressure magnitude increases non-linearly when the distance to track centre decreases. Importantly, the height of noise barrier is also an important factor affecting pressure magnitude on noise barriers and when the height of noise barrier increases, the pressure magnitude gradually increases but tends to be stable at higher heights. An exponential equation can well characterize such effect of height of noise barrier on train-induced aerodynamic pressure.

Place, publisher, year, edition, pages
Institute of Physics Publishing (IOPP), 2024
Series
Journal of Physics: Conference Series (JPCS) ; 2647
Keywords
Railway noise barrier, CFD simulation, Aerodynamic pressure, High-speed train
National Category
Civil Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-101565 (URN)10.1088/1742-6596/2647/10/102002 (DOI)001329172800076 ()2-s2.0-85197809488 (Scopus ID)
Conference
XII International Conference on Structural Dynamics, Delft, Netherlands, July 2-5, 2023.
Funder
Swedish Transport Administration, BBT-2019-022
Note

Full text license: CC BY 4.0;

Available from: 2023-10-04 Created: 2023-10-04 Last updated: 2025-10-21Bibliographically approved
Liu, D., Wang, C., Guo, T., Gonzalez-Libreros, J., Ge, Y., Tu, Y., . . . Sas, G. (2024). Time–depth dependent chloride diffusion coefficient of self-compacting concrete. Magazine of Concrete Research, 76(12), 600-616
Open this publication in new window or tab >>Time–depth dependent chloride diffusion coefficient of self-compacting concrete
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2024 (English)In: Magazine of Concrete Research, ISSN 0024-9831, E-ISSN 1751-763X, Vol. 76, no 12, p. 600-616Article in journal (Refereed) Published
Place, publisher, year, edition, pages
ICE Publishing, 2024
National Category
Civil Engineering Materials Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-103740 (URN)10.1680/jmacr.23.00237 (DOI)001134369300001 ()2-s2.0-85180960487 (Scopus ID)
Note

Validerad;2024;Nivå 2;2024-05-21 (joosat);

Available from: 2024-01-16 Created: 2024-01-16 Last updated: 2025-10-21Bibliographically approved
Liu, D., Wang, C., Gonzalez-Libreros, J., Guo, T., Cao, J., Tu, Y., . . . Sas, G. (2023). A review of concrete properties under the combined effect of fatigue and corrosion from a material perspective. Construction and Building Materials, 369, Article ID 130489.
Open this publication in new window or tab >>A review of concrete properties under the combined effect of fatigue and corrosion from a material perspective
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2023 (English)In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 369, article id 130489Article, review/survey (Refereed) Published
Abstract [en]

When in use, reinforced concrete bridge structures not only experience high-frequency fatigue loading caused by passing vehicles, but also suffer from the effects of a corrosive environment. In addition to fatigue damage to reinforcement, long-term fatigue loading also causes concrete cracking and deterioration of pore structures, thereby accelerating the ingress of external corrosive substances and reducing concrete durability. Long-term exposure to a corrosive environment also reduces the performance of concrete and causes corrosion of reinforcement materials, affecting the fatigue performance of the structure. Therefore, there is a combined effect between fatigue loads and corrosion on concrete. This paper is a review of the current literature from a material perspective on the performance degradation of concrete under the combined action of fatigue loading and corrosion, that is, carbonation, chloride ion attack, freeze–thaw cycles, and sulphate attack. The paper includes (1) a description of a test method for examining the combined action of fatigue loading and corrosion, (2) a summary of performance degradation of concrete under the combined effect of fatigue loading and corrosion, and (3) an introduction to durability deterioration models considering fatigue damage, and fatigue models that can account for corrosion. Finally, potential future research on concrete under the combined effect of fatigue loading and corrosion is described.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Concrete, Fatigue load, Corrosion, Combined action, Carbonation, Chloride attack, Freeze–thaw cycles, Sulphate attack, Deterioration, Modelling
National Category
Infrastructure Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-95539 (URN)10.1016/j.conbuildmat.2023.130489 (DOI)000927776800001 ()2-s2.0-85147195723 (Scopus ID)
Funder
Swedish Transport Administration
Note

Validerad;2023;Nivå 2;2023-02-08 (hanlid);

Funder: FOI-BBT program (BBT-2019-022)

Available from: 2023-02-08 Created: 2023-02-08 Last updated: 2025-10-21Bibliographically approved
Liu, D., Wang, C., Gonzalez-Libreros, J., Tu, Y., Elfgren, L. & Sas, G. (2023). A review on aerodynamic load and dynamic behavior of railway noise barriers when high-speed trains pass. Journal of Wind Engineering and Industrial Aerodynamics, 239, Article ID 105458.
Open this publication in new window or tab >>A review on aerodynamic load and dynamic behavior of railway noise barriers when high-speed trains pass
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2023 (English)In: Journal of Wind Engineering and Industrial Aerodynamics, ISSN 0167-6105, E-ISSN 1872-8197, Vol. 239, article id 105458Article in journal (Refereed) Published
Abstract [en]

Noise barriers need to be installed along high-speed railway lines to protect nearby inhabitants from the noise pollution caused by the running of high-speed trains (HSTs). The vertical noise barrier is the main structural type. However, when an HST passes through the noise barriers sited along the track, significant and transient aerodynamic pressure will act on the surface of the noise barriers, resulting in strong dynamic responses and even fatigue damage. Therefore, it is important to determine the train-induced aerodynamic load on the barrier surface and analyze the dynamic behaviors of the noise barriers under such a load for its structural design and to guarantee its safety and durability. This paper is a systematic review of the current literature on the aerodynamic load and dynamic behavior of vertical noise barriers; it includes (1) a summary and analysis of characteristics of such aerodynamic pressure and relevant influencing factors, (2) an introduction to measurement methods of aerodynamic load and relevant pressure models on the surface of noise barriers, and (3) a description of the dynamic response and fatigue analysis of noise barriers under such loads. Finally, potential further studies on this topic are discussed, and conclusions are drawn.

Place, publisher, year, edition, pages
Elsevier, 2023
Keywords
Noise barrier, Railway, High-speed train, Aerodynamic load, Dynamic response, Fatigue
National Category
Vehicle and Aerospace Engineering
Research subject
Structural Engineering
Identifiers
urn:nbn:se:ltu:diva-98162 (URN)10.1016/j.jweia.2023.105458 (DOI)001015391400001 ()2-s2.0-85160798389 (Scopus ID)
Funder
Swedish Transport Administration, “Excellence Area 4” and FOI-BBT program (grant number BBT-2019-022)
Note

Validerad;2023;Nivå 2;2023-06-12 (joosat);

Licens fulltext: CC BY License

Available from: 2023-06-12 Created: 2023-06-12 Last updated: 2025-10-21Bibliographically approved
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ORCID iD: ORCID iD iconorcid.org/0000-0003-2668-1329

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