Abstract
This paper proposes a mathematical planning model to find the most effective links to be fortified, in order to secure the inter-city passenger transportation service facing to interdiction risk of each link in the network. If interdicted, the passengers must find a minimum time detour route and endure additional travel time. We assume that fortification of a link can avoid the risk of interdiction. The planning model is formulated based on the Multi-modal Network Planning (MNP) model formulated by the authors. This paper shows the model formulation and case study on a simple network including the introduction of emergent airline service after interdiction of railway links, as an illustration of the potential of the model.