Abstract
Understanding how urban systems and traffic dynamics co-evolve is crucial for advancing sustainable and resilient cities. However, their bidirectional causal relationships remain underexplored due to challenges of simultaneously inferring spatial heterogeneity, temporal variation, and feedback mechanisms. Here we present a spatio-temporal causality framework that bridges correlation and causation by integrating spatio-temporal weighted regression with spatio-temporal convergent cross-mapping. Characterizing cities through urban structure, form, and function, the framework uncovers bidirectional causal patterns between urban systems and traffic dynamics across 30 cities on six continents. Our findings reveal asymmetric bidirectional causality, with urban systems exerting stronger influences on traffic dynamics than the reverse in most cities. Urban form and function shape mobility more profoundly than structure, even though structure often exhibits higher correlations. This does not preclude the reversed causal direction, whereby long-established mobility patterns can also reshape the built environment over time. Finally, we identify three causal archetypes: tightly coupled, pattern-heterogeneous, and workday-attenuated, which support city-to-city learning and inform context-sensitive strategies in sustainable urban and transport planning.
Data availability
The traffic datasets used to compute traffic dynamics indicators can be downloaded through the HERE API (https://www.here.com/developer). OSM and GADM data, used for computing urban system metrics, can be publicly accessed from https://download.geofabrik.de/and https://gadm.org/data.html, respectively. The urban and traffic feature data generated in this study have been deposited in Figshare: https://doi.org/10.6084/m9.figshare.28656800. Source data are provided with this paper.
Code availability
All codes that support the findings of this study are available in Figshare via the following link: https://doi.org/10.6084/m9.figshare.28656800.
References
Xu, F., Li, Y., Jin, D., Lu, J. & Song, C. Emergence of urban growth patterns from human mobility behavior. Nat. Computat. Sci. 1, 791–800 (2021).
Pappalardo, L., Manley, E., Sekara, V. & Alessandretti, L. Future directions in human mobility science. Nat. Comput. Sci. 3, 588–600 (2023).
Cao, J. et al. Untangling the association between urban mobility and urban elements. Geo-Spat. Inf. Sci. 27, 1071–1089 (2024).
Dong, L. et al. Defining a city-delineating urban areas using cell-phone data. Nat. Cities 1, 117–125 (2024).
Zhang, Y. & Raubal, M. Street-level traffic flow and context sensing analysis through semantic integration of multisource geospatial data. Trans. GIS 26, 3330–3348 (2022).
Xu, Y. et al. Urban dynamics through the lens of human mobility. Nat. Comput. Sci. 3, 611–620 (2023).
Liu, J. & Yuan, Y. Exploring dynamic urban mobility patterns from traffic flow data using community detection. Ann. GIS 30, 435–454 (2024).
Batty, M. Building a science of cities. Cities 29, S9–S16 (2012).
Lämmer, S., Gehlsen, B. & Helbing, D. Scaling laws in the spatial structure of urban road networks. Phys. A Stat. Mech. Appl. 363, 89–95 (2006).
Xie, F. & Levinson, D. Measuring the structure of road networks. Geogr. Anal. 39, 336–356 (2007).
Crooks, A. et al. Crowdsourcing urban form and function. Int. J. Geogr. Inf. Sci. 29, 720–741 (2015).
Boeing, G. Spatial information and the legibility of urban form: Big data in urban morphology. Int. J. Inf. Manag. 56, 102013 (2021).
Arribas-Bel, D. & Fleischmann, M. Spatial signatures-understanding (urban) spaces through form and function. Habitat Int. 128, 102641 (2022).
Miotti, M., Needell, Z. A. & Jain, R. K. The impact of urban form on daily mobility demand and energy use: evidence from the United States. Appl. Energy 339, 120883 (2023).
Wang, M. & Debbage, N. Urban morphology and traffic congestion: longitudinal evidence from US cities. Comput. Environ. Urban Syst. 89, 101676 (2021).
Zhang, Y., Zhao, T., Gao, S. & Raubal, M. Incorporating multimodal context information into traffic speed forecasting through graph deep learning. Int. J. Geogr. Inf. Sci. 37, 1909–1935 (2023).
Gan, Z., Yang, M., Feng, T. & Timmermans, H. J. Examining the relationship between built environment and metro ridership at station-to-station level. Transp. Res. Part D Transp. Environ. 82, 102332 (2020).
Choi, D. -a & Ewing, R. Effect of street network design on traffic congestion and traffic safety. J. Transp. Geogr. 96, 103200 (2021).
Rahman, M. M., Najaf, P., Fields, M. G. & Thill, J.-C. Traffic congestion and its urban scale factors: Empirical evidence from American urban areas. Int. J. Sustain. Transp. 16, 406–421 (2022).
Xiao, D., Kim, I. & Zheng, N. Does built environment have impact on traffic congestion?-A bootstrap mediation analysis on a case study of Melbourne. Transp. Res. Part A Policy Pract. 190, 104297 (2024).
Ma, X., Zhang, J., Ding, C. & Wang, Y. A geographically and temporally weighted regression model to explore the spatiotemporal influence of built environment on transit ridership. Comput. Environ. Urban Syst. 70, 113–124 (2018).
Liu, H. et al. Exploring the effect of built environment on spatiotemporal evolution of traffic congestion using a novel gtwr model: a case study of Hefei, China. Transp. Lett. 17, 869–880 (2025).
Kan, Z., Liu, D., Yang, X. & Lee, J. Measuring exposure and contribution of different types of activity travels to traffic congestion using GPS trajectory data. J. Transp. Geogr. 117, 103896 (2024).
Cornacchia, G., Pappalardo, L., Nanni, M., Pedreschi, D. & González, M. C. A computational framework for quantifying route diversification in road networks. Preprint at https://arxiv.org/abs/2510.02582 (2025).
Zhu, H., Zhang, K., Wang, C., Jia, L. & Song, S. The impact of road functions on road congestions based on POI clustering: an empirical analysis in Xi’an, china. J. Adv. Transp. 2023, 6144048 (2023).
Yu, X., Chen, Z., Liu, F. & Zhu, H. How urban metro networks grow: from a complex network perspective. Tunn. Undergr. Space Technol. 131, 104841 (2023).
Rohrer, J. M. Thinking clearly about correlations and causation: graphical causal models for observational data. Adv. Methods Pract. Psychol. Sci. 1, 27–42 (2018).
Deng, Z. et al. Compass: Towards better causal analysis of urban time series. IEEE Trans. Vis. Comput. Graph. 28, 1051–1061 (2021).
Zhang, Y., Xu, F., Xia, T. & Li, Y. Quantifying the causal effect of individual mobility on health status in urban space. Proc. ACM Interact. Mob. Wearable Ubiquitous Technol. 5, 1–30 (2021).
Mao, J. et al. A convergent cross-mapping approach for unveiling congestion spatial causality in urban traffic networks. Comput. Aided Civ. Infrastruct. Eng. 40, 301–322 (2025).
Gan, T., Succar, R., Macrì, S., Marín, M. R. & Porfiri, M. Causal discovery from city data, where urban scaling meets information theory. Cities 162, 105980 (2025).
Wang, Y., Yang, X. & Wang, Z.-H. Causal mediation of urban temperature by geopotential height in US cities. Sustain. Cities Soc. 100, 105010 (2024).
Akbari, K., Winter, S. & Tomko, M. Spatial causality: a systematic review on spatial causal inference. Geogr. Anal. 55, 56–89 (2023).
Gao, B. et al. Causal inference from cross-sectional earth system data with geographical convergent cross mapping. Nat. Commun. 14, 5875 (2023).
Cattaneo, A. et al. Worldwide delineation of multi-tier city–regions. Nat. Cities 1, 469–479 (2024).
Zhang, Y., Song, S., Li, X., Gao, S. & Raubal, M. Leveraging context-adjusted nighttime light data for socioeconomic explanations of global urban resilience. Sustain. Cities Soc. 114, 105739 (2024).
Wegener, M. Land-use transport interaction models. in Handbook of Regional Science, 229–246 (Springer, 2021).
Geurs, K. T., Niemeier, D. & Giannotti, M. The uneven geography of the accessibility and environmental quality in the global north and south: Introduction to the special issue. J. Transp. Geogr. 97, 103216 (2021).
Runge, J. et al. Inferring causation from time series in Earth system sciences. Nat. Commun. 10, 2553 (2019).
Sharif, M. & Alesheikh, A. A. Context-awareness in similarity measures and pattern discoveries of trajectories: a context-based dynamic time warping method. GIScience Remote Sens. 54, 426–452 (2017).
Diao, M. Towards sustainable urban transport in singapore: policy instruments and mobility trends. Transp. Policy 81, 320–330 (2019).
Metz, D. Tackling urban traffic congestion: the experience of London, Stockholm and Singapore. Case Stud. Transp. Policy 6, 494–498 (2018).
Buser, M. A., Ramezani, S., Stead, D. & Arts, J. Policy packaging for land-use and transport planning: the state-of-the-art. Transp. Rev. 45, 333–365 (2025).
Wang, Y., Geng, K., May, A. D. & Zhou, H. The impact of traffic demand management policy mix on commuter travel choices. Transp. Policy 117, 74–87 (2022).
Cheng, Z., Pang, M.-S. & Pavlou, P. A. Mitigating traffic congestion: the role of intelligent transportation systems. Inf. Syst. Res. 31, 653–674 (2020).
Yildirimoglu, M. & Ramezani, M. Demand management with limited cooperation among travellers: a doubly dynamic approach. Transp. Res. Part B Methodol. 132, 267–284 (2020).
Zhu, J. Y. et al. pg-causality: Identifying spatiotemporal causal pathways for air pollutants with urban big data. IEEE Trans. Big Data 4, 571–585 (2017).
Li, L. et al. Robust causal dependence mining in big data network and its application to traffic flow predictions. Transp. Res. Part C Emerg. Technol. 58, 292–307 (2015).
Næss, P., Peters, S., Stefansdottir, H. & Strand, A. Causality, not just correlation: residential location, transport rationales and travel behavior across metropolitan contexts. J. Transp. Geogr. 69, 181–195 (2018).
Hassan, A. M. & Lee, H. Toward the sustainable development of urban areas: an overview of global trends in trials and policies. Land Use Policy 48, 199–212 (2015).
Acuto, M. & Leffel, B. Understanding the global ecosystem of city networks. Urban Stud. 58, 1758–1774 (2021).
Verendel, V. & Yeh, S. Measuring traffic in cities through a large-scale online platform. J. Big Data Anal. Transp. 1, 161–173 (2019).
Zhang, Y., Wang, Y., Gao, S. & Raubal, M. Context-aware knowledge graph framework for traffic speed forecasting using graph neural network. IEEE Trans. Intell. Transp. Syst. 26, 3885–3902 (2025).
Vargas-Munoz, J. E., Srivastava, S., Tuia, D. & Falcao, A. X. Openstreetmap: Challenges and opportunities in machine learning and remote sensing. IEEE Geosci. Remote Sens. Mag. 9, 184–199 (2020).
TomTom. TomTom Traffic Index 2023 https://www.tomtom.com/traffic-index. Accessed 1 June 2024. (2023).
Yang, X. et al. Revealing the relationship of human convergence–divergence patterns and land use: a case study on Shenzhen City, China. Cities 95, 102384 (2019).
Kumar, N. & Raubal, M. Applications of deep learning in congestion detection, prediction and alleviation: a survey. Transp. Res. Part C Emerg. Technol. 133, 103432 (2021).
Neun, M. et al. Metropolitan segment traffic speeds from massive floating car data in 10 cities. IEEE Trans. Intell. Transp. Syst. 24, 12821–12830 (2023).
Yu, H., Yang, J., Li, T., Jin, Y. & Sun, D. Morphological and functional polycentric structure assessment of megacity: an integrated approach with spatial distribution and interaction. Sustain. Cities Soc. 80, 103800 (2022).
Etzkowitz, H. & Zhou, C.The Triple Helix: University–Industry–Government Innovation and Entrepreneurship (Routledge, 2017).
Wu, C., Smith, D. & Wang, M. Simulating the urban spatial structure with spatial interaction: A case study of urban polycentricity under different scenarios. Comput. Environ. Urban Syst. 89, 101677 (2021).
Wu, C.-Y., Hu, M.-B., Jiang, R. & Hao, Q.-Y. Effects of road network structure on the performance of urban traffic systems. Phys. A Stat. Mech. Appl. 563, 125361 (2021).
Zhang, P., Ghosh, D. & Park, S. Spatial measures and methods in sustainable urban morphology: a systematic review. Landsc. Urban Plan. 237, 104776 (2023).
Zhang, Y. et al. Functional urban land use recognition integrating multi-source geospatial data and cross-correlations. Comput. Environ. Urban Syst. 78, 101374 (2019).
Zhong, Y. et al. Global urban high-resolution land-use mapping: from benchmarks to multi-megacity applications. Remote Sens. Environ. 298, 113758 (2023).
Fotheringham, A. S., Yang, W. & Kang, W. Multiscale geographically weighted regression (MGWR). Ann. Am. Assoc. Geogr. 107, 1247–1265 (2017).
Que, X., Ma, X., Ma, C. & Chen, Q. A spatiotemporal weighted regression model (stwr v1.0) for analyzing local nonstationarity in space and time. Geosci. Model Dev. 13, 6149–6164 (2020).
Shrestha, N. Detecting multicollinearity in regression analysis. Am. J. Appl. Math. Stat. 8, 39–42 (2020).
Fotheringham, A. S., Yu, H., Wolf, L. J., Oshan, T. M. & Li, Z. On the notion of ‘bandwidth’ in geographically weighted regression models of spatially varying processes. Int. J. Geogr. Inf. Sci. 36, 1485–1502 (2022).
Runge, J., Gerhardus, A., Varando, G., Eyring, V. & Camps-Valls, G. Causal inference for time series. Nat. Rev. Earth Environ. 4, 487–505 (2023).
Sugihara, G. et al. Detecting causality in complex ecosystems. Science 338, 496–500 (2012).
Wang, K. & Gasser, T. Alignment of curves by dynamic time warping. Ann. Stat. 25, 1251–1276 (1997).
Rezatofighi, H. et al. Generalized intersection over union: a metric and a loss for bounding box regression. In Proc. IEEE/CVF Conference on Computer Vision and Pattern Recognition, 658–666 (IEEE, 2019).
Acknowledgements
The research was conducted at the Future Resilient Systems at the Singapore-ETH Centre, which was established collaboratively between ETH Zurich and the National Research Foundation Singapore. This research is supported by the National Research Foundation Singapore (NRF) under its Campus for Research Excellence and Technological Enterprise (CREATE) programme (Y.Z., M.R.).
Funding
Open access funding provided by Swiss Federal Institute of Technology Zurich.
Author information
Authors and Affiliations
Contributions
Y.Z. and M.R. conceived the study. Y.Z. developed the methodology, implemented the software, and wrote the original draft. Y.Z. and Y.H. conducted the analysis. All authors reviewed and edited the manuscript. M.R. and S.G. supervised the project.
Corresponding author
Ethics declarations
Competing interests
The authors declare no competing interests.
Peer review
Peer review information
Nature Communications thanks Klavdiya Bochenina and Luca Pappalardo for their contribution to the peer review of this work. A peer review file is available.
Additional information
Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
Supplementary information
Supplementary Information (download PDF )
Reporting Summary (download PDF )
Transparent Peer Review file (download PDF )
Source data
Source Data (download XLSX )
Rights and permissions
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Reprints and permissions
About this article
Cite this article
Zhang, Y., Hong, Y., Gao, S. et al. Bidirectional yet asymmetric causality between urban systems and traffic dynamics in 30 cities worldwide.
Nat Commun (2026). https://doi.org/10.1038/s41467-026-71377-0
Received:
Accepted:
Published:
DOI: https://doi.org/10.1038/s41467-026-71377-0
Source: Ecology - nature.com
