Optimizing investment decisions for railway systems protection

As demonstrated by recent events, railway systems are often the target of terrorist bombings and attacks. To preserve public safety and essential economic functions, railroad networks should be made as secure and resilient as possible. However, railway protection investments may involve significant and often unaffordable capital expenditure. Given the limited resources available for protection efforts, it is essential that a strategic approach to the planning of security investments is adopted. This chapter presents a mathematical model for identifying the optimal allocation of protective resources among the components of a railway network. The aim is to minimize the impact on passenger flow of worst-case disruptions which might affect both railway stations and tracks. The proposed model is tested on an Italian railroad network to demonstrate how the model results can be used to inform policy making and protection investment decisions.