Depending on what ends up in the initial release of the game I would suggest most public transportation be developed in a subterrainian setup. It would allow for better use of the surface and increase aesthetics while also being easier to defend or shut down these modes of transportation if invading forces attempt to use them.

In the image, you will see the sketch of a building which is mostly underground, but with large holes in the ground letting people have window rooms and a small park at the bottom. There is also a nice park on top. Thought it would be worth pointing out this style of building.