I've drafted norfv system "Norway Primære Fylkesveier" back in 2017 but it's getting a little bit more complicated due to a regional reform.
Norway plans a renumbering of many Fylkesveier (Fv routes) but also some Riksveier (Rv routes) will be renumbered.
Rv routes (green) and primary Fv routes (white) are signed and in HB. Primary Fv routes are former Rv routes now maintained by districts. They have usually just replaced the Rv prefix by Fv prefix.
Secondary Fv routes are also maintained by districts and not signed. Their numbering is not unique, e.g. there's might be a Fv1 in each district. In addition, primary Fv routes have the same numbering starting with Fv7!
Due to a regional reform planned for 2020, road numbering should be harmonized so that a road number is unique and doesn't change its number at district borders.
It seems to be planned that secondary Fv routes will get 4-digit numbers. They are not in HB but used for wp labels of routes in HB.
First renumberings appear in field and even
Rv routes have been renamed.
It seems that each county council must approve the changes.
Some info.
I need to revise the whole region including active systems before norfv will be ready for a review.
However, it's seems to be too early to start because it's not yet clear what's the overall plan.
I wanna gather relevant info on this thread.
Update
2019-05-14.
Some major renumberings.
Update 2020-03-22: map indicating old and new numberings.