Fire evacuation in underground transportation systems: a review of accidents and empirical research

A review of literature related to fire evacuation in underground transportation systems, e.g., tunnels and subway stations, was carried out with the objectives (1) to identify a theoretical framework that can help understand of human behaviour in the event of a fire in underground transportation systems, (2) to use the theoretical framework to analyse and to identify problems related to fire evacuation in underground transportation systems, and (3) to suggest areas on which future research should focus on in. The review included literature on past accidents in underground transportation systems, theories and models on human behaviour in fire, and empirical research. It was concluded that the adoption of a clear theoretical framework can aid the understanding of people’s behaviour in the event of a fire in underground transportation systems, and that a behaviour that seems irrational to an outside observer seldom is. The theoretical framework should include the behaviour sequence model, the affiliative model, social influence, and the theory of affordances. It was also concluded that one of the major issues related to fire evacuation in underground transportation systems is that people often are reluctant to initiate evacuation, which among other things is explained with a role keeping behaviour, lack of information, ambiguity of fire cues and the presence of others, i.e., social influence. Other factors that affect the actual movement of people in underground transportation systems were identified as problems with the door-opening mechanisms on trains, the vertical distance between train and tunnel floor, that people tend to evacuate through familiar exits, the lack of lighting, and uneven surfaces inside tunnels. The review demonstrated that there are room for improvements in the area of fire evacuation in underground transportation systems, and future research should among other things study the effects of a comprehensive evacuation system, the optimal design of active systems in underground transportation systems, and the possibility for people with disabilities to evacuate from these types of facilities. © Copyright: Department of Fire Safety Engineering and Systems Safety, Lund University. Lund 2010. Department of Fire Safety Engineering and Systems Safety Lund University P.O. Box 118 SE-221 00 Lund Sweden [email protected] http://www.brand.lth.se/english Telephone: +46 46 222 73 60 Fax: +46 46 222 46 12 Brandteknik och Riskhantering Lunds tekniska högskola Lunds universitet Box 118 221 00 Lund [email protected] http://www.brand.lth.se Telefon: 046 222 73 60 Telefax: 046 222 46 12 i Summary In recent year the number of rail and road tunnels has increased, and today the possibility to travel underground is taken for granted by most people. In addition, the average of length of the tunnels has increased in recent years. The demand on society to handle fire and evacuation safety in these types of facilities, which in this report is termed underground transportation systems, has therefore increased. Past accidents in both rail and road tunnels illustrate that a fire in a underground transportation systems can result in devastating consequences in terms of loss of life. This is, for instance, illustrated by the fire at the King’s Cross station in 1987, where 31 people were killed, by the fire in Kaprun in 2000, which claimed the lives of 155 people, and by the fire in Baku’s Metro in 1995, which claimed the lives of 289 people. These, and other accidents in underground transportation systems, reveal problems related to the evacuation process. Although there are many similarities when comparing evacuation in underground transportation systems with evacuation in a traditional building, there are also many differences that need to be acknowledged in the design phase, as well as during the operation, in underground transportation systems. By combining the observations form past accidents with conclusions from empirical research, future research areas for improving the safety in underground transportation systems can be identified. The purpose of this report was therefore to review and to summarize literature related to fire evacuation in underground transportation systems, and to suggest areas for future research in the field. The studied literature can roughly be divided into three categories: (1) past accidents in underground transportation systems, (2) theories and models on human behaviour in fire, and (3) empirical research related to evacuation in underground transportation systems. It was concluded that human behaviour in fire is complex and that it sometimes can seem irrational to a person studying the behaviour in retrospect. But instead of using ‘panic’ to describe the human behaviour and the outcome of an accident, the adoption of a clear theoretical framework could aid the understanding of people’s behaviour, also in underground transportation systems. This theoretical framework should include the behaviour sequence model, the affiliative model, social influence and the theory of affordances. One of the major issues related to fire evacuation in underground transportation systems is that people often are reluctant to initiate an evacuation. This is explained by a number of factors: • That people tend to maintain their roles (e.g., as passengers) • The lack of fast, clear and coherent information • The ambiguity of the cues from the source of danger (e.g., a fire) • The presence of others, i.e., social influence Furthermore, when an evacuation has been initiated there are other factors that affect the efficiency of the evacuation. Some of the problems that was identified are: • Problems with the door-opening mechanism on trains • The vertical distance between the train and the tunnel floor • That people tend to evacuate through familiar exits • Lack of lighting • Uneven surfaces inside the tunnels