[OSM-dev] osm2pgsql, direction of a virtual way (based on a route)

[marqqs at gmx.eu]

Thanks, this helps a lot!

> The direction of each resulting LineString should be the direction of 
> the majority of constituting ways.

That explains a some issues in openptmap at zoom level 17.

> > Are role tags "forward" and "backward" evaluated?
> Not at all.

Could it be done in osm2pgsql somehow?

The new public transport schema makes it necessary to take the member roles into account. Most of them are redundant; it would suffice to read the role of the first listed way and to use this role when determining the direction of the LineString. This would be the rule:

- First way has role "forward": The whole LineString inherits the direction from this way.
- First way has role "backward": The whole LineString inherits the opposite direction from this way.