The aAccidents leading to very terrible disasters are particularly those wthoat produce the fire. Each time, three main dangers occur during a fire are three: the toxicity of smoke, the lack of visibility due to the smoke's opacity, and the high temperatures, which can cause the collapseing of the structure of the tunnel by exceeding the threshold conditions. Then a question should be asked, not only about the safety of the users, but also about the safety of tunnels, that has become a major issue to humans and politics.