Decision support for emergency road traffic management in post-earthquake conditions

Road network systems play a critical role in the emergency phase following an earthquake, since they constitute the main vector of transportation of rescue teams, first-aid responders or victims in need of evacuation. While several studies have focused on how to organize multi-agent travels via a traffic plan, the present work focuses on how to immediately help first-aid responders, at a moment when the actual damage state of the road network is still mostly unknown. Therefore, in such an uncertain context, a probabilistic framework is used in order to evaluate the failure probability of exposed road components and the accessibility probability between two locations of the network, via a decomposition into minimum link sets. Such data is then used to extract relevant indicators for each potential travel itinerary, such as the expected travel time (accounting for potential disruptions along the route and the need to use a back-up itinerary) or the reliability of the itinerary and its back-ups. Given predefined road user profiles, with different weightings of indicator preferences, the various travel options may be evaluated in a decision matrix in order to assist the choice of the most adequate itinerary. Finally, such as decision support system is demonstrated on a road network in the Pyrenees mountain range (France), where several travel options (i.e., fastest or safest routes from the damaged area to nearby hospitals, or from rescue centres to the damage area) are evaluated for a few earthquake scenarios and characteristic user profiles.