It must be quite common where there's not much love is lost between neighbours.

I don't think that's unreasonable at all, actually. I'd expect liminal spaces, especially entrances, to get a little more attention to their presentation than other places - everybody knows first impressions are important, right?

And even in between counties. I cross the county line between a well-funded suburban county and a dirt-poor rural county occasionally and the road quality is night and day.

The Netherlands is too small to put effort in one particular area. It's like painting with too big of a brush.

So wait... Non-American countries exist?

In my experience the Belgian roads are much worse, but my experience is hardly definitive..

can you translate?

Stupid sexy Flanders!

Don't get fooled again!

I think you are under interpreting. The road is absolutely too small for two cars, and it's showing that bikes have priority on that part of the road. If two cars are in the center car lane, they must wait for the bike lanes to be clear to pass each other, it's not first come, first served as a road with no bike lanes would be.

It's allowed for cars to cross the line as long as no cyclists are present.

Actually, because the bike lane has a dotted line as a border AND a bike logo in it (repeated every 250m or something), vehicles MAY cross said line (for passing or overtaking) but a bicycle has right of way in that lane.

This way you can make a 2 lane road a 4 lane road for slow traffic.

As others have already mentioned, bikes have priority here. There is another aspect, however.

This scheme also intentionally makes the road look narrower than it actually is, which naturally makes people drive slower.