Welcome to this issue of Proceedings of the Institution of Civil Engineers – Transport in 2026. The papers gathered here are connected by a clear theme: transport infrastructure can no longer be planned, operated or maintained as a static asset. Climate exposure, seismic risk, digital inspection, railway modernisation and regional sustainability now require engineers to combine physical modelling, data-driven analysis and long-term policy thinking. In my view, the value of transport research is increasingly defined by its ability to connect technical precision with practical resilience.
The first paper, by Ma and Xu (2026), addresses this challenge in cold-region tunnels by examining anti-freezing defence through the daily temperature cycle rather than relying only on annual temperature fluctuation. Their numerical analysis shows how positive and negative temperature alternations weaken with radial depth and longitudinal distance from the lining surface. The work provides useful guidance for frost-resistant fortification length and zoning, reminding practitioners that short-term environmental variability can be as important as long-term averages.
Urban maintenance and intelligent inspection are represented by Ji et al. (2026), who propose GSGAA-Yolo, a lightweight deep-learning model for concrete crack detection. The model achieves 88.2% mean average precision, improves on the baseline YoloV11 model, and reduces the number of parameters and computational load by 24% and 19%, respectively. This contribution is important because artificial intelligence becomes most valuable when it can be deployed efficiently in real inspection environments, not only demonstrated in controlled computational settings.
At a broader network scale, Zhang et al. (2026) investigate the impact of high-speed rail development on provincial carbon dioxide emissions in China. Using provincial data and spatial econometric modelling, the study shows that high-speed rail network development reduced both total and transport carbon dioxide emissions, while also revealing significant regional heterogeneity. The paper highlights an essential policy message: low carbon dioxide transport strategies should consider substitution effects, spatial spillovers and regional development differences together.
Safety and dynamic performance are central to the paper by Huang et al. (2026), which studies the seismic behaviour of a high-speed maglev (magnetic levitation) vehicle–guideway system under vertical earthquakes. By modelling the vehicle as a multi-rigid-body system and the guideway as a Bernoulli–Euler beam, the authors show that vertical seismic excitation can significantly amplify levitation-gap fluctuation, car-body vibration and guideway response. Their finding that seismic travelling-wave velocity should not be ignored is particularly relevant for elevated high-speed systems in earthquake-prone areas.
At the track-structure level, Zemin et al. (2026) investigate ballast bed settlement and compactness increment under dynamic stabilisation using a response surface method supported by coupled discrete-element, finite-element and multi-body dynamics modelling. The study highlights the importance of accurately calibrating sleeper–ballast and ballast–ballast contact parameters and demonstrates that reliable prediction of settlement and compactness changes can be achieved, with prediction errors below approximately 11%. These findings have practical relevance for improving railway maintenance operations and supporting the optimisation of dynamic stabilisation parameters.
Finally, Wang et al. (2026) extend the discussion to regional systems by analysing transport–environment–economy linkages in the Yellow River basin’s ‘Ji-shape’ bend metropolitan area. Their coupling coordination and GM (1,1) modelling show improvement from near imbalance towards marginal coordination, while also identifying persistent spatial differences among cities. This paper reminds us that transport infrastructure should be assessed not only by mobility outputs but also through its interaction with ecological protection and economic development.
Taken together, these articles reflect a discipline that is expanding in both scale and responsibility: from tunnel linings, concrete cracks and ballast particles to high-speed systems, carbon dioxide reduction and regional coordination. They also show the importance of methodological diversity, including numerical simulation, artificial intelligence, spatial econometrics and systems analysis. Such diversity is not simply academic variety; it is essential for decision making in a world where infrastructure must be safe, sustainable, adaptive and evidence-based.
On behalf of the editorial panel, I am pleased to present this issue of Transport. I extend my sincere thanks to the authors for their valuable contributions and to the reviewers for their careful work in maintaining the journal’s standards. I hope readers will find these papers useful and stimulating. Readers are also encouraged to follow the journal’s newest accepted articles ahead of print through Emerald Early Cite, which provides timely access to emerging research in the field.
