Routing in Road Networks with Transit Nodes

Years and Authors of Summarized Original Work

• 2007; Bast, Funke, Sanders, Schultes

Problem Definition

For a given directed graph ${ G = (V,E) }$ with non-negative edge weights, the problem is to compute a shortest path in G from a source node s to a target node t for given s and t. Under the assumption that G does not change and that a lot of source‐target queries have to be answered, it pays to invest some time for a preprocessing step that allows for very fast queries. As output, either a full description of the shortest path or only its length d(s, t) is expected – depending on the application.

Dijkstra's classical algorithm for this problem [4] iteratively visits all nodes in the order of their distance from the source until the target is reached. When dealing with very large graphs, this general algorithm gets too slow for many applications so that more specific techniques are needed that exploit special properties of the particular graph. One practically very relevant case...