Not really a fair comparison. How much does labor cost in Shanghai vs NYC? How much existing 100+ year old underground infrastructure does Shanghai have? New s

Not really a fair comparison. How much does labor cost in Shanghai vs NYC? How much existing 100+ year old underground infrastructure does Shanghai have? New subway lines in NYC can't use the latest technology. They're being integrated into an existing 112-year-old subway system with the highest station count and track mileage in the world. I'd make a software development analogy, but it would be woefully inadequate at comparing the scope of the situation.