> > The problem probably only occurs with ways close to the tile
> > boundary that are clipped. I don't know if we can save a route
> > restriction when the to-node or from-node lies outside of the boundary.
>
> Would it solve the problem if the boundary nodes are added earlier just
> before the RestrictionRelation.addRestriction(MapCollector) is called?

The boundary nodes are added for all ways before style processing, even for
all non-routable ways and shapes.
This wastes a few cpu cycles, but I don't see a problem or a solution here.

Gerd