In Transit to Constant Time Shortest-Path Queries in Road Networks
Holger Bast, Stefan Funke, Domagoj Matijević, Peter W. Sanders, Dominik Schultes · Society for Industrial and Applied Mathematics eBooks · 2007
When you drive to somewhere 'far away', you will leave your current location via one of only a few 'important' traffic junctions.Starting from this informal observation, we develop an algorithmic approach-transit node routingthat allows us to reduce quickest-path queries in road networks to a small number of table lookups.We present two implementations of this idea, one based on a simple grid data structure and one based on highway hierarchies.For the road map of the United States, our best query times improve over the best previously published figures by two orders of magnitude.Our results exhibit various trade-offs between average query time (5 µs to 63 µs), preprocessing time (59 min to 1200 min), and storage overhead (21 bytes/node to 244 bytes/node).