A case study of critical point identification in the physical and communication layers of a small urban transportation system

Surface transportation is an important critical infrastructure as it provides the essential services that highly impact a nation's economy. It is important to identify and protect the essential components of the transportation system to ensure its survivability. This paper describes critical point identification of a small urban intelligent transportation network. The analysis was conducted for two layers: physical/control and communication layers. Microscopic simulation modelling was used to identify critical points in the physical/control layer. The critical point identification of the communication layer was done using graph metrics such as hop counts and dependencies. A final node ordering with regard to both layers is then obtained using the criticality values identified for each layer. The critical point identification approach presented in this paper provides transportation professionals with a tool to identify critical nodes that need to be strengthen and hardened to achieve a survivable transportation network.