Quantitative Risk Assessment of Road Tunnel Fire Safety: Improved Evacuation Simulation Model

Abstract

With a view to enhance road network’s safety, it is crucial to focus primarily on its critical infrastructures, one part of which is tunnels. Fire safety of tunnels concerned intensely the public opinion after the disastrous trans-Alpine accidents in Europe in the late 1990s. Therefore, risk assessment was officially introduced for ensuring the tunnels’ level of safety. Bearing in mind that trapped-users’ performance can strongly determine a tunnel’s level of safety, this paper proposes an evacuation simulation model for increasing the efficiency of quantitative risk assessment. The model aims at acting as an add-in to the traditional computational fluid dynamics models by linking their results with trapped-users’ evacuation. The model structure is twofold. Initially, through estimating potential losses among trapped-users, the effectiveness of important parameters for the safety of the tunnel system is measured. Subsequently, if needed, the performance of additional to standard safety measures is examined. The model aids safety analysts in making better-informed decisions regarding a tunnel’s level of safety. An application example is presented to illustrate the utilization of the model.