They sad that tunnels are on the list but whats the situation right now? Will it come on a DLC? Or on a future patch? Please this is important for late game.
European wall-to-wall buildings are one of the first things we will look into after the launch (with tunnels).
And those roads can curve and be propped up as bridges or tunnel through mountains and spin around like big tarmac ribbons, all as you'd pretty much expect from a city builder in 2015. Cities Skylines borrows a few districting ideas from Sim City too, allowing you to zone for industry, commerce and residential in the spaces naturally created between roads.