if they parallel roads, fine they can, but it needs to be separated by a significant distance.  motorways are great because they tend to clear more trees than necessary to run the cars and they better not use the same road for safety. however there appears to be segments that actually do share the road like near https://www.openstreetmap.org/way/61845922 and even https://www.openstreetmap.org/way/18008786 - I guarantee these OHV will be using the road and not running through the trees.

IMHO these things should be dual use with other ohv like dirt bikes during the summer when there is no snow, and thus should see tire tracks in the dirt.  Some are visible and those should indeed be tracks.  others... they should be shared with the existing road.