The $50 million per mile figure was from a congressional research bureau earlier this year.
I’ll defer to real numbers...
Yeah, we saw how "accurate" that Congressional research was, when passing Obamacare!
Seattle's Sound Transit spent $179 million per mile for light rail, and that was predominantly at-grade light-rail as well. Elevating or building dedicated heavy-rail rights-of-way is considerably more expensive.
My guess is we'll spend over $200 million per mile for any high speed rail systems installed. That $2 trillion estimate for a high speed rail network in the US will most likely be closer to $8 trillion, and the financing will go from $7.5 billion a month in interest to $30 billion a month.