Route Planning in Transportation Networks Hannah Bast1, Daniel Delling2, Andrew Goldberg3, B Matthias M¨uller-Hannemann4, Thomas Pajor5( ), Peter Sanders6, Dorothea Wagner6, and Renato F. Werneck3 1 University of Freiburg, Freiburg im Breisgau, Germany
[email protected] 2 Apple Inc., Cupertino, USA
[email protected] 3 Amazon, Seattle, USA {andgold,werneck}@amazon.com 4 Martin-Luther-Universit¨at Halle-Wittenberg, Halle, Germany
[email protected] 5 Microsoft Research, Mountain View, USA
[email protected] 6 Karlsruhe Institute of Technology, Karlsruhe, Germany {sanders,dorothea.wagner}@kit.edu Abstract. We survey recent advances in algorithms for route plan- ning in transportation networks. For road networks, we show that one can compute driving directions in milliseconds or less even at continen- tal scale. A variety of techniques provide different trade-offs between preprocessing effort, space requirements, and query time. Some algo- rithms can answer queries in a fraction of a microsecond, while others can deal efficiently with real-time traffic. Journey planning on public transportation systems, although conceptually similar, is a significantly harder problem due to its inherent time-dependent and multicriteria nature. Although exact algorithms are fast enough for interactive queries on metropolitan transit systems, dealing with continent-sized instances requires simplifications or heavy preprocessing. The multimodal route planning problem, which seeks journeys combining schedule-based trans- portation (buses, trains) with unrestricted modes (walking, driving), is even harder, relying on approximate solutions even for metropolitan inputs. 1 Introduction This survey is an introduction to the state of the art in the area of practical algo- rithms for routing in transportation networks.