Ranking of alternatives for emergency routing on urban road networks

Routing on urban road networks for emergency cars is an application of Dijkstra’s algorithm with relevance in everyday-life. Since distances in urban transport are rather short it is computationally possible to calculate many paths and compare them afterwards. This paper uses Dijkstra’s k-shortest path algorithm in order to calculate shortest and fastest paths and finally finding an ordering of alternatives for multi-criteria routing. The solutions are displayed in criterion space and the Pareto front is identified. Routes are ranked according to the normalized weighted-sum method. Obviously, the more alternatives there are the more possibilities for the emergency car to circumscribe traffic jams. Therefore ‘close alternative routes’ are taken into accounts that share a certain fraction of nodes with one Pareto optimal route. To those bundles of routes a ranking is assigned that may serve as recommended action for the driver.