i lived in boston during (the tail end of) the big dig and remember the excess costs were largely due to corruption and maybe some incompetence. look at how much nicer it is there because of it. i'd vote for it again in a heartbeat (with some better processes and oversight of course).

but yes, underground infrastructure is expensive (maybe the boring company will help drive equipment costs down), but we're a rich nation and we want nice things. i think we can do it if we want to. plus, it creates working class jobs and that makes the economy go 'round.