That's an interesting question.  First, there's the question of who actually owns the land occupied by the road.  That may depend on how the deeds are written.  When it comes to PUBLIC roads, the general rule is that each abutter actually owns the land under the road to the center line of the road even if his deed doesn't say so, unless the road was taken "in fee simple" by the public.  But I don't think that rule applies to private roads.  So who does own it?  I know of one case where the subdivider sold his last lot and deeded the ownership of the roads within the subdivision to his wife.  I thought this rather odd, and wrote and asked him whether that meant his wife was still a land owner who would owe dues to the association.  He wrote back, showing me where the Town listed that neither he nor his wife still owned any land within the town.  (Then what does the deed grant her?)  

Other than that, my general experience has been that once a subdivider has sold his last lot, he generally disappears from the picture and will accept no responsibility for anything.  If the road association fails, the road will not get maintained until it gets bad enough to motivate someone to go to the work of setting up a new road association.

Unless the language used in the grant of the easement specifies some duty of the landowner to provide maintenance, I don't think the person whose land it crosses is obligated to do anything other than to allow the owners of the easement to use it as an easement.  Sometimes it has even been argued that the grant needs to specifically allow the grantee to perform maintenance, or he has no such right; however, I believe the Courts have said the right to maintain the easement is assumed.  Otherwise it would eventually cease to be of any use as an easement.  So I don't think the owner of the land under the easement is responsible for any maintenance, although if he also uses the easement he would be expected to contribute his fair share.  That being said, the owner of the land should not be obstructing the easement, or doing anything that would create a hazard to those to whom the easement is granted.  (For example, putting an unmarked cable across it, or digging a drain ditch across it.)  Note: This is my opinion as a layman.  I am not an attorney.