Résumé en anglais

Users of transport infrastructures nearby hazardous plants may represent important populations potentially impacted by a major accident. Toulouse catastrophe in 2011 has been an illustrative example as it strongly impacted highway users. Therefore, transport infrastructure users (Roads and railways mainly) represent a population to be protected within a land use planning policy as it is the case for inhabitants.Accordingly, this paper presents a decision support approach aiming to help local stakeholders identifying the most cost effective measures to protect transport infrastructures from major accidental consequences. The suggested approach takes in account both technical and participatory constraints with the aim of offering an equal chance to all involved stakeholders to understand the issues under discussion and formulate opinions and values.After a description of the French regulatory context, the major technical difficulties related to transport infrastructures protection will be described before introducing the main technical choices adopted by the team. Finally, a decision support procedure is described and a real case study presented.This work is strongly embedded in the French regulatory context. However, we believe the decision support structure as fully adaptable to other regulatory contexts.