How socio-political streams shape sustainability transitions: the case of a European rail network

In current times of deep socio-ecological crises, political-economic governance of key infrastructural sectors such as energy and mobility is reconsidered by society, politics and academia alike. This paper explores how the dynamics of political economies influence sustainability transitions. Beyond static country comparisons, we develop a processual perspective on political economy that better resonates with the long-term nature of sustainability transitions. To analyze struggles over political directionality, we draw on literature on political ideologies and introduce the concept of socio-political streams. Socio-political streams refer to actor coalitions and their interrelated sets of goals, beliefs, practices and affects. Conceptually, our study provides insight in how political-economic debates about the role of state and market, as well as international integration, shape sustainability transitions. Empirically, we conduct a case study of international rail connections in Western Europe. Recent years have seen a push for rail revival, but developments seem to have stalled. We analyze 25 years (2000–2024) of media, sector and policy documents from seven countries (Germany, The Netherlands, France, Belgium, Austria, Switzerland and the United Kingdom) and conduct interviews with 26 sectoral informants. We study socio-political dynamics using qualitative content analysis and socio-technical configuration analysis. The results reveal how socio-political streams shape international rail in divergent ways, influencing policy choices, financing models, and creating barriers such as high track access charges under market-based approaches. Overall, the coexistence of conflicting socio-political streams without prioritization has stalled progress, with a potential path forward emerging through stronger coordination by the European Union.