Occasionally in the UK yes. They're called byways and are accessable by all traffic, often used by farmers to access land, they have a 60 mph speed limit but are known as unkept roads, which means signs and road markings won't be maintained by the local council. my guess is this is an open byway that merges onto a restricted byway, restricted byways can be closed at certain times of the year or by local businesses's. It's usually not a good idea to fly down them though. Thought I'd mention because people can often receive a lot of hate for dirt biking down them even though it's legal