Towards a dynamic evacuation system: developing methodologies to simulate the evacuation capabilities of subway stations in response to a terrorist attack with CBRNE weapons

Events in recent times have highlighted the vulnerability of underground public transportation to possible terrorist attacks. A key question therefore is how an evacuation can be accomplished from underground stations safely. The strategy "go up and take the nearest exit to the surface" might not be the best response. Evidence from the Daegu subway station fire in 2003, investigated by Tsujimoto (2003) and Jeon and Hong (2009) establish that smoke or toxic airborne substances from a terrorist attack tend to use the same direct routes used by the fleeing passengers and as result significant injuries or fatalities can occur. This study proposes the concept of a dynamic evacuation system which would guide subway users along safe routes. To test how this system may operate, the study discussed combines measurements from tracer gas experiments with climate measurements to establish how toxic agents spread in subway stations under certain conditions and combines these results with those from pedestrian simulations applied to calculate evacuation times for possible escape routes. By integrating the resulting dataset from these methods, an evidence base of how a dynamic evacuation system may work can start to form.