[Routing] Tools for getting from OSM to a routable network

[Christian Vetter]

On Mon, Sep 22, 2014 at 12:16 AM, Geoff Leyland
<geoff_leyland at fastmail.fm> wrote:
> So I just store the forward star and no node locations (no two-way searches or A-star here, sorry).  I could do a little better and only store one cost.  I’m not aware of a good way of ordering the nodes (some kind of space-filling algorithm perhaps?)  I order them so that the intersection arcs are near the feeder road arc, but beyond that it’s just sorting by some hand-wavy criteria so that there’s some diff stability.

Try Hilbert Curves to order the nodes, usually gives you a factor of
2-3 in performance over a random node order. Alternativly, Z-Order
(Morton Codes) are easier to compute and only 10-15% slower. These
orderings will also be stable, i.e. you can remove and add nodes and
it will not change the relative order of others.

Best regards,

Christian Vetter