I'm Lucy, and I'd be happy to answer your questions today.
In order for the adjoining lot owners to get a prescriptive easement across your lots, they must have been using it without the consent of the prior owner(s) for 15 years. If they did that, it's true that they might have a continue right to cross the land - but unless the lot is barely bigger than a car width, that shouldn't prevent you from still using the land. There's no reason you shouldn't be able to build on the lot and leave a road for the neighbors. Also - how is this the government's business? The neighboring landowners are the ones who should be bringing the suit IF they want to continue crossing the properties. A prescriptive easement is typically a defense to a trespassing action or something filed by an individual who is being blocked from using land. You could actually file a Motion to Dismiss for lack of standing, because this isn't the government's problem. (Of course, if you do that, you should be prepared for the possibility that the neighbors will sue you).
You can also counterclaim against the government for violating the Fifth Amendment's Takings Clause. By preventing you from doing anything with your property, they have committed a taking and therefore owe you just compensation (meaning that, if they are able to stop you from building on your lots, they'll have to basically buy the property back from you).
One way to make the whole thing go away is to see if they will agree to allow you to build on the lots if YOU agree to grant a written easement for access across the property to the adjoining landowners, and to install a road for them to use (which it would be up to them to maintain). But before you do that, they need to prove that the neighbors meet the requirements of a prescriptive easement (so, 15 years of use). Otherwise, they'd have to pay you for the right to use that part of your land. A fair price would be based on the value per square footage of the land, times the total amount of land being used, minus a portion because you'd still be able to use the road, too.
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