Publication Details

Keep, D., Piper, I. & Green, A. (2013). An investigation of the effectiveness of interdiction regimes against terrorist attacks in an urban transport hub. In J. Piantadosi, R. S. Anderssen & J. Boland (Eds.), 20th International Congress on Modelling and Simulation (pp. 1096-1102). Australia: The Modelling and Simulation Society of Australia and New Zealand Inc.


This paper examines the effect of varying attack and interdiction strategies, both alone and in combination, in an urban transport hub. Particular attention is paid to the potential disruption to normal commuter services resulting from an intrusive stop and search regime. The work presented here represents a qualitative investigation in that many parameters relating to the details of the interdiction mechanisms are first-order approximations. However, the background against which the investigation is conducted has been constructed to be as realistic as possible. The simulation is performed using our generalised microsimulation framework Simulacron , along with a reper- toire of simulation modules. Changes and additions to these modules required for the present study are de- scribed. The station is modelled using 454 distinct locations, most of which are interconnected to form a directed graph to permit commuter movement. An average of some 8,300 commuters move through the station, outbound and inbound. Figure 1 is a frame from the baseline simulation of the station, generated by a custom post-processing tool and rendered by LightWave, showing commuters and trains. The train schedule is constructed from the real schedule for the 3 rd of June, 2013. It is from this that the commuter population is derived. Five attack strategies (including no attack) are matrixed against four interdiction strategies (including no pro- tection) to produce 20 scenarios. Some key results are presented, along with brief remarks on the remainder. An additional 30 variant scenarios were used to examine a stop and search interdiction strategy. For these scenarios, impact on commuters was inferred from the number of outbound commuters missing their intended train, how long commuters spent waiting in checkpoint queues, and the size of these queues, on average and at peak. Congestion at the search point was also used as an indication of the increased vulnerability resulting from stop and search. Our conclusions from this work are that overt, intrusive protection schemes appear to be more efficacious than passive or covert means. However, the former present their own problems in both disruption to commuter activities and the creation of new potential targets. In the case of stop and search, this takes the form of unacceptable commuter delays and congestion at the checkpoints. As a result of this, the overall interdiction regime must be adjusted to protect the new target. Doing so without introducing additional targets may prove challenging. It seems that the "best" likely outcome is to redirect the terrorist attack to a softer target.