Had a boss who went back there when it was new. Loveed it.
Do those things every pay their own way?
https://www.washingtonpost.com/local/trafficandcommuting/with-robberies-on-metro-increasing-some-riders-worry-for-their-safety/2016/01/09/cc92de90-b549-11e5-a842-0feb51d1d124_story.html
I used to do a bit of transportation planning in my salad days.
The short answer is no.
The only system that comes close to covering operating cost is NYC. That is due to the churning of the fare box, many off and on riders, lots of short rides, constant use. All other systems must receive operating subsidies.
All modern systems could only be built with massive federal capital grants.
In addition the energy used in constructing underground systems is never recovered or offset by energy savings through use.
Like almost all things in America, it is a boondoggle to support dying, corrupt, and decayed cities by redistributing money from earners to takers. It is the avowed policies of all democraps and their quisling republicans that this continue.