Cycling infrastructure between towns

That’s not clear-cut either. The definition of highway=tertiary in Norway leaves a signficant judgement to the mapper. highway=secondary requires you to have access to the government road database to tag it according to the NO wiki, and other roads may even require you to know their numbering history to know for certain how to tag them.

I’m sure this isn’t unique to NO.

Leaving some judgement to the mapper for cycleways doesn’t seem unreasonable.

In NO, all cycleways are owned by someone. Typically the county will own the cycleways that are related to county roads, whose ownership define them as either primary or secondary roads. So we could use the same ownership as a basis to tag these cycleways as primary or secondary cycleways.

Etc.

They’re not always part of a route relation.