Combining the Connection Scan Algorithm with Contraction Hierarchies

Since the first solutions finding minimally weighted routes in weighted digraphs, a plethora of literature has appeared improving the performance of shortest-path queries for use in real-world applications. In this paper, we detail how an advanced pre-processing technique for routing algorithms (which create objects known as Contraction Hierarchies) may be combined with the connection scan algorithm, an algorithm originally designed to work with public transportation networks using time tables. This provides an improvement over bi-directional Dijkstra or A${}^*$ search on Contraction Hierarchies.