Emergency Evacuation of Railway Tunnels: A Simulation Study of Passenger Movement under Fire

This study examines the effect of fire gases on passengers’ flow during emergency evacuation from a long operational railway tunnel (8 km in length), given the tunnel’s current facilities and infrastructure, and compares it with an ideal scenario. One of the most important challenges in spaces with high populations occurs during emergency evacuation time in fire events since most injuries stem from inhaling toxic gases produced by the fire. Real conditions of the tunnel, such as emergency exit doors and ventilation, and assumptions, such as the train stop location and changes in the tunnel facilities, were considered. The effect of toxic gas inhalation evaluated on the passengers’ movement in 12 different scenarios and provided some suggestions for a safe evacuation in the shortest time. The Available Safe Egress Time was extracted from previous studies, and the base time of emergency evacuation simulation was inserted in the Pathfinder software. The results showed that the tunnel’s current status in the study area (1000-m section of the tunnel) was the worst possible outcome with over 55% of nonevacuated people. However, the construction of a separation wall with doors at distance of 100 or 200 meters (converting into a double tunnel) will result in the evacuation of 100% of passengers even without ventilation.