Map Routing, a la Google Maps?

Question

I\'ve always been intrigued by Map Routing, but I\'ve never found any good introductory (or even advanced!) level tutorials on it. Does anybody have any pointers, hints, etc?

Answer 1

By Map Routing, you mean finding the shortest path along a street network?

Dijkstra shortest-path algorithm is the best known. Wikipedia has not a bad intro: http://en.wikipedia.org/wiki/Dijkstra%27s_algorithm

There's a Java applet here where you can see it in action: http://www.dgp.toronto.edu/people/JamesStewart/270/9798s/Laffra/DijkstraApplet.html and Google you lead you to source code in just about any language.

Any real implementation for generating driving routes will include quite a bit of data on the street network that describes the costs associate with traversing links and nodes—road network hierarchy, average speed, intersection priority, traffic signal linking, banned turns etc.