Participatory governance and rail mobility: lessons and prospects for SERMs[Gouvernance participative et mobilité ferroviaire : enseignements et perspectives pour les SERM]

Participatory governance is now seen as an essential lever for guiding and legitimising public action, particularly in spatial planning and mobility. The French Metropolitan Regional Express Services (SERM) projects are part of this dynamic, establishing it as a central principle. However, their specificities - service-oriented, multimodal, multi-scale and multi-stakeholder - complicate their implementation, without a theoretical or operational framework being clearly established. This article aims to shed light on these issues through a critical review of participatory approaches in rail mobility planning at the national, regional and metropolitan levels. It also draws on an in-depth analysis of the SERM Clermont-Auvergne case, based on focus groups and mapping tools, in order to assess their contributions to a co-design approach. Our review shows that, at the national level, the participatory approaches often remain confined to top-down information sharing, with little articulation between the participatory process and project engineering. At regional and metropolitan levels, despite more suitable tools for understanding service logic and territorial dynamics, participation remains unevenly mobilized and poorly integrated into decisions. The case study highlights the interest of an anticipated, progressive and visual approach, which encourages iteration, understanding of the issues and the formulation of collective proposals. However, it also reveals the persistent limitations of innovative geo-governance approaches that hinder co-design: lack of inclusion, weak appropriation by stakeholders, and lack of methodological framework. Several recommendations are therefore proposed to structure a method of active participation, reproducible and adapted to the requirements of the multi-criteria planning of complex mobility services, such as those of SERM.