You mean the huge underground train station & several miles of tunnels around if, with all the work preformed underneath an undisturbed city?
Yes, that is still waaay cheaper than constructing an underground highway of that magnitude/that area (+ an underground station you conveniently included in the estimate) .
You mean the huge underground train station & several miles of tunnels around if, with all the work preformed underneath an undisturbed city?
Yes, that is still waaay cheaper than constructing an underground highway of that magnitude/that area (+ an underground station you conveniently included in the estimate) .
Or did you have something else in mind?
Why would you build the highway underground?
Same reasons as railway I suppose - its expensive to destroy a city centre to get the land needed for it.
But you started the comparison with the underground thing.