[Routing] Fast Routing Engine - State of Play

[VeaaC FDIRCT]

On Fri, Apr 16, 2010 at 12:56 PM, Jens Müller <blog at tessarakt.de> wrote:
> As you have probably looked into that in quite some detail: Is it
> necessary to do precomputations for every edge length function to be
> used (e.g., car, pedestrian, mountain bike, racing bike, $userdefined)?
> Or can the algorithm deal with small modifications?

The current implementation can only deal with fixed edge length, thus
you'd have to precompute a Contraction Hierarchy for every objective
function you'd like to supply. While dealing with linear combinations
of objective functions is possible [1], it is quite complex. However,
the precomputation of Contraction Hierarchies is quite fast and
techniques used for Mobile Contraction Hierarchies [2] can be used to
avoid loading the whole Contraction Hierarchy into memory during route
computations. This makes it possible for a single server to provide a
larger amount of objective functions while still maintaining fast
query times.

Greetings

Chris

[1] http://algo2.iti.kit.edu/english/1440.php
[2] http://algo2.iti.kit.edu/english/1187.php