Charlotte (NC) is going through the process of building it right now. The city is in the massive cost overrun/review/tax increase stage. Totally predicted by every one but the politicians who pushed it...also totally predictable.
Over a billion $$, you say? Great. It's going to be fun to watch the politicians try to sell that here.
About half the money was Federal. They have all sorts of grandiose plans for more lines, hopefully the Republicans in this state will grow a spine and put an end to this foolishness before it wastes any MORE money.