Risk-informed decision support for assessing the costs and benefits of counter-terrorism protective measures for infrastructure

The paper describes risk-informed decision support for assessing the costs and benefits of counter-terrorism (CT) protective measures for infrastructure. Such a decision support framework needs to consider threat scenarios and probabilities, value of human life, physical (direct) damage, indirect damage, risk reduction and protective measure costs. Probabilistic terrorism risk assessments that quantify the costs and benefits are conducted for three items of infrastructure using representative cost and vulnerability data. The illustrative examples show under what combination of risk reduction, threat probability, and fatality and damage costs the CT protective measures would be cost-effective for United States building, bridge and aviation infrastructure. It was found that if indirect losses (such as business interruption, loss of GDP, etc.) are considered, then CT protective measures are cost-effective even if the terrorist threat probability is not high. Opportunity costs can be considerable, which makes CT protective measures less cost-effective.