> The sea generator of course adds the sea area with multiple polygons and
> also adds the land area with multiple polygons. They are used only if
> you have an according rule in the style. I don't see a chance to change
> anything here.

I agree. Sorry, I did not want to say that this should be changed.

>
> The question is why the highwayCount is > 1.
> I have searched where the highwayCount is increased.
> Some places are quite understandable but two are conspicuous:
>
> Osm5XmlHandler.startInNode checks for a tag mkgmap:on-boundary. If that
> is set the highwayCount is increased. So far so good but this is not
> performed in the PBF and o5m handler. So maybe this can be removed or
> must be added to the other handlers too.
>
> The base class OsmHandler has a method addCoordToWay(..). In this method
> the highwayCount is increased always - no matter if it is a way or not.
> This was introduced by merging the way-closing branch.
> So Steve should have a look on it. I think that's not intended.

yes, I think so as well.
I don't fully understand what the removeShortArcsByMergingNodes() should do with coast line data
and I don't know why the PreserveHorizontalAndVerticalLinesFilter() is needed.
Maybe we can omit these routines for ways that were created by the sea generator.

Gerd