|Tile Chart - Units 1&2|
|A yellow tile with two small stations can be upgraded to any
green tile with one station and the same exits.|
#69 does not upgrade.
|A yellow tile with one small station can be upgraded to any green tile with one station.|
|A yellow tile with one large station can be upgraded to any green tile with one large station.|
|Green tiles with stations have no neat summary rule.|
|Value-40 russets upgrade in Phase Four.|