Influence of panic on human behaviour during emergency egress for tunnel fires

Tunnel fires represent a complex multidisciplinary problem of great importance for the Safety Engineering, where different aspects converge and add difficulties in studying and modeling the phenomenon. The confined geometry, traffic conditions and different, sometimes inap-propriate, safety measures are combined with the unavoidable presence of humans inside vehicles, making tunnel systems highly dangerous and risky: an extreme action like a fire or an explosion can cause severe effects depending on the fire development and the occupant characteristics, both physical and cognitive. In such environment, panic often drives people actions: the main negative consequence is the increase of the evacuation time, called RSET (Required Safety Evacuation Time). As the evacuation time grows, the exposure time at high temperatures and smoke increases and so the possibility for people of getting intoxicated. This paper is thought as the prosecution of other two papers: “Risk analysis for severe traffic accidents in road tunnels” (Di Santo et al., Proceeding IF CRASC’ 15) and “Computational fluid dynamics simulations for the assessment of a road tunnel fire safety” (Baroncelli et al., Proceeding IF CRASC’ 15) in which the concepts of hazard and risk for tunnels are widely described. The aim of this paper is to highlight the importance of considering human behaviour for the Fire Safety Engineering and the possibility of its modeling with numerical codes as FDS+Evac, giving as example the study of different egress scenarios for a 3 km – long – tunnel placed in the Catania – Syracuse Highway.