Serious accidents, which occurred in France in road tunnels in the 2000’s, have revealed specific risks related to tunnels, along with safety management issues. The lessons learned analyses are one resource used by tunnel operators to improve safety. How these processes are linked to the actual collective safety management practices ? The conception of a process that takes into account these practices in order to improve individual, collective and organizational capacities will also be focused on. We will show, based on concrete examples, that a procedure of participative conception based on debates about practices between different professions, and also based on an organizational simulation lead us to devise an integrated ‘lessons learned process’. We will also see that this process allowed the development and the validation of the reflexive skills of the involved professionals, and that it contributed to the improvement and the evolution of a collective safety management from a professional and inter-professional point of view, as well as to the development of work groups.