> The most flabbergasting thing was the absence of Metro ring lines around the center. The fact these have not been built, in 2025, when Metro transport networks in most cities are now over a century old, is telling.

I'm having trouble imagining where a useful ring line could exist in the New York metropolitan area or within the city itself, given its geography, longstanding commuter movement patterns and other characteristics. Maybe you could have a relatively small ring just in midtown Manhattan?