Since 1950, the study of tunnel fires has improved over the years by requiring a real need to achieve technical objectives in the area of safety while preserving some limits imposed by technical means. Different organizations and academic laboratories have conducted experimental research programs on this topic and developed a predictive simulation tools system. This helps to lighten procedures based on functional requirements to design a suitable solution tfor each tunnel. The study of fires in confined and ventilated mechanical environments can be produced by using different techniques: testing nature, experimental scale models and CFD numerical modeling.