Feedback from operational experience, mainly in the form of accident analysis, is the method of choice for safety management in high-risk organizations. The research presented here concerns the domain of road tunnels, and is based on feedback of the day-to-day experience of tunnel monitoring staff in collective discussion spaces. Our novel, participatory approach encompassed operating staff, managers and research partners, and transformed the feedback scheme. Inter-profession debate spaces, run by team leaders, were set up to analyse simulated events. These structured spaces proved to be an effective way to compare working practices, events and role representations, and were conducive to knowledge transmission. The debate allowed workers to establish transverse operational rules, and highlighted the need for formal rules to be set by the management. The spaces were effective in improving the formal organization, and extending the activities of operational staff. The methodology was found to support gaining experience through a process of event analysis.