Establishing public policy to protect critical infrastructure: Finding a balance between exposure and cost in Los Angeles County

This paper examines the problem of critical infrastructure protection in urban environments and provides a mechanism for evaluating the performance allocated resources on defense of the region. In the devised formulation, a bi-level mixed integer program and hypercube queuing model compose the mathematical model used to represent the concept of critical infrastructure protection between an attacker and a defender operating within the urban environment and an experimental design is used as the basis for observing salient properties and trends. Applying the model within Los Angeles County, California, results demonstrate the trade-offs observed in various protection schemes and illustrate how continuously increasing defense resources does not guarantee a safer region. The implication of detection strategy on response capability is also assessed through the case study, illustrating the importance of balance when deriving solutions. We also show how the mathematical model may be used to support research and development in defense technologies by identifying resource characteristics that strongly influence infrastructure protection.