[OSM-talk] colour fills in osmarender

[Richard Fairhurst]

Etienne wrote:

> Are loops and branches in ways a good thing or a bad thing?   I can
> imagine that route planning applications might find them problematic,

My approach when (intermittently) working on an OSM route-planner has  
been that the ways and segments tables are nowhere near consistent or  
optimised enough to be directly of use.

Consequently, I have a "paths" table, which is assembled as a  
derivative of the existing tables. Broadly speaking, each path goes  
from a junction (i.e. three or more segments meeting at a node) to  
another junction. It is "painted" with the key/value pairs that apply  
to the way which it follows. (This means that, sometimes, a 'junction'  
will simply be where one way ends and another starts with differing  
characteristics.)

Using this has reduced the iterations required by the route-planning  
algorithm by $lots.

Richard