MeusH wrote: Just tunnels in tunnels and bridges in tunnels should be prohibited. As long as we're not making a huge cave a'la underground climate
bridges in tunnels will simply be an UP-and-OVER tool. tunnels in subways will be a DOWN-and-UNDER tool.
of course their menu entries will be totally nonrelated to either bridges or tunnels, it will be a unique logo for the situation, but no you will not be able to build a "structure" of a bridge, or a tunnel, inside subways.
anyway all normal tunnels will be visualised as subways anyway, so subways are just tunnels, (with up and down possibilities)
this will also allow for tunnels to be built into hills, such as spirals, and Zig-zags. this will hopefully let trains go at high speed up steep or impassable terrain.
of course it will come at a cost.
Alltaken