Naslov
TRANSIT: Ultrafast Shortest-Path Queries with Linear-Time Preprocessing

Autori
Bast, Holger ; Funke, Stefan ; Matijević, Domagoj

Vrsta, podvrsta i kategorija rada
Poglavlja u knjigama, znanstveni

Knjiga
The Shortest Path Problem: Ninth DIMACS Implementation Challenge

Urednik/ci
Demetrescu, Camil ; Goldberg, Andrew V. ; Johnson, David S.

Izdavač
American Mathematical Society (AMS)

Grad
New York (NY)

Godina
2009

Raspon stranica
175-192

ISBN
0-8218-4383-4

Ključne riječi
Shortest paths, Transit nodes, Road maps

Sažetak
We introduce the concept of transit nodes, as a means for preprocessing a road network, with given coordinates for each node and a travel time for each edge, such that point-to-point shortest-path queries can be answered extremely fast. The transit nodes are a set of nodes, as small as possible, with the property that every shortest path that is non-local in the sense that it covers a certain not too small euclidean distance passes through at least on of these nodes. With such a set and precomputed distances from each node in the graph to its few, closest transit nodes, every non-local shortest path query becomes a simple matter of combining information from a few table lookups. For the US road network, which has about 24 million nodes and 58 million edges, we achieve a worst-case query processing time of about 10 microseconds (not milliseconds) for 99 % of all queries. This improves over the best previously reported times by two orders of magnitude.

Izvorni jezik
Engleski

Znanstvena područja
Matematika, Računarstvo

POVEZANOST RADA