I wonder if there’s a particular reason they want that 9 inches. I have a weird property line issue at my home, so I can appreciate what a difference a few inches can make.
My property line runs up the center of my driveway, but the other half of the driveway and a couple of feet on that side are technically part of a neighboring lot. You might think that the owner/occupant of the neighboring lot is the other party that uses the driveway, but you’d be wrong. The driveway is the only access to, and only the access to, my property and a THIRD lot which doesn’t own a single square inch of the driveway or the ground on the far side of it. There are now lateral support issues developing which will eventually require me and the other property owner who is entitled (by deed) to access via the driveway, to force the owner of the property to shore up his collapsed retaining wall that is causing “his” side of the driveway to collapse, even though he has no use whatsoever for half a driveway that doesn’t provide access to his property, so he doesn’t give a cr@p about it.
Re the couple foot wide strip of ground on that side of the driveway, for several years up until a few weeks ago, it was sporting a progressively leaning 10 foot chain link fence with 3 rows of rusty barbed wire on top. The lean had literally reached a 45 degree angle (fortunately towards HIS property). The fence serves no purpose whatsoever, since it’s at one side of his parking lot (it’s a commercial property), and another side is completely unfenced and can be driven onto from the street at any point. The fence was just hauled upright by the new tenant at his own expense, using guywires planted a couple of inches from the edge of the driveway (for liability reasons, as he reasonably feared the thing would fall on his customers parked cars), but is still hideous and serving no purpose whatsoever.
If I got control of that little strip of land, I could get rid of the d@mn fence and fix the retaining wall and re-pave the driveway without dealing with the pain-in-the-@ss owner. I’m plenty willing to pay to get all that work done, but not when somebody else owns the property and is free to do things like leave an ugly massive fence leaning at a 45% angle.
Other than property rights issues, sometimes there is a FAR zoning issue , or insurance issues.
What if someone slips on some ice and gets hurt. Does your insurance cover your land that has their driveway which is not properly maintained ?
A trip to the county courthouse (or the county GIS site) would probably reveal that your shared driveway is on a prescriptive easement, so adverse possession would not apply.
That's the question I always have, too.