With highways in their current form all adjacent tiles get full adjacency bonus from them, this allows highway tiles to be used as 'filler' to make a nursery fully upgradable:
This also removes the necessity to build chambers:
I think giving highways the same adjacency bonus as a wall makes building in chambers a necessity if the player wants to fully upgrade their tiles.
This also removes the necessity to build chambers:
I think giving highways the same adjacency bonus as a wall makes building in chambers a necessity if the player wants to fully upgrade their tiles.