In Norway there are some private roads, which typically lead up from the villages, into the woods / mountains, and are therefore interesting candidates to drive and explore.
Typically rewarded with a fantastic view at the top...
Most of these Private Roads are generally open to the public.
They typically have a sign at the gate, which is usually closed (to stop animals - but not locked).
The sign usually say "Private Road - Pay Toll Fee - Close Gate after Use"
Next to the gate is usually a small box.
Inside the box are forms, a pen and a honesty (payment) box.
Fill in the form (name, date, vehicle registration) and rip-off the receipt stub (with form number) for proof of purchase.
Pay the Road Toll Fee (typically 50-100kr ($5-10), sometimes 150kr ($10-15) into the honesty box (always good to have bag of small change in vehicle).
Some also supply electronic payment options (Account Numbers for bank transfer, if you don't have cash on you at the time - Trust is a big thing in Norway).
If you get stopped by the road owner along the way, they typically just ask:
Are you ok?
Know where you are going?
Did you pay? (almost never ask to see receipt - they trust your reply)
They may provide tips of conditions along the way
Very rare is the case, where you are "not welcome" on these private roads.
In these cases, it usually clearly states this at the gate
"Private Road - No Entry"
So it's quite easy to differentiate where you are welcome, and where you need to stay out.
If you do find yourself on a private road and not welcome, and there was no sign to indicate otherwise, you are usually just asked to leave.
Luckily for us, no guns or serious threats occur.
You just apologies and wish the owner a good day...
As long as you use common sense, pay the small toll fees, and behave sensibly, then you are usually allowed to do a lot in Norway.
Access is seen as a "right" in Norway, with virtually all the mountains, fjords, forests, and roads, accessible to the general public.
Hope this was useful / informative.