The Peer owns the land and the roadways. The fact that he has allowed a museum to be sited & operated on his land was surely his decision. His land, his road.
A fund setup to level up the poorer areas of the country pays for the upkeep of a private road owned by a multi-millionaire. I'm sorry, you literally could not make this up. There is also a business (
Tilton House) that clear benefits from the works and so erodes any (weak) attempt at justification.
This is clearly another sleaze own goal despite the half hearted attempts of some on this forum to explain it away.