Evacuation of a Metro Train in an Underground Rail Transportation System: Flow Rate Capacity of Train Exits, Tunnel Walking Speeds and Exit Choice

Including in total 135 participants in the ages 19-69 years (recruited from the general public), an unannounced full-scale field evacuation experiment was performed in the Stockholm underground metro system on the night between October 17 and 18, 2014. The purpose was to collect data on the flow rate of people in train exits during the evacuation of a train in a tunnel and on the walking speed of people when moving long distances on an uneven surface in a tunnel, and to study exit choice and behaviour during an evacuation. Consequently, the experiment involved the evacuation of a rail car (a Bombardier C20 train) in a tunnel as well as the subsequent evacuation of the tunnel itself; the latter meant that the participants either could evacuate to the closest station (similar to 400 m) or to an available emergency exit (similar to 200 m). Among other things, the experiment demonstrated that the averaged flow rates of people in the train exits varied between 0.19 p/s and 0.22 p/s (0.14-0.16 p/m s when considering the train exit width of 1.4 m) and that the averaged walking speeds in the tunnel varied between 1.1 m/s and 1.2 m/s (no smoke present). Furthermore, all 135 participants found and used the available emergency exit, which had been equipped with a technical system consisting of a loudspeaker that broadcasted a combined alarm signal and a pre-recorded voice message.