This is my contribution with pak128.Britain (with a lot of Add-ons):
These are Cambridge and Rhyl metropolitan area.
As they grow each other, they found a way to be together.
Far from today are the times where a bus linked the cities centres.
Nowadays they share the same Airport (Cambridge Lowgate Airport) and two Maglev InterCity stations.
For urban transport, they share a tram line, an above-surface Maglev line and a Maglev subway system.
These cities are strong on farm production.
Surrounding the cities, we have production of: cows, milk, meat, vegetables, fruit, cider and even fish.
Connecting this farms to big distribution centres we have a Maglev Cargo line and trucks leaving every hour.
The farm workers have lines that link the work place to the cities lines: from bus and tram. There is a post truck line too.
These systems require constant optimization, as the two cities grow off barriers...
PS: This is a real game.