This article is interesting: https://www.nytimes.com/2017/12/28/nyregion/new-york-subway-construction-costs.html https://www.nytimes.com/2017/12/28/nyregion/new

This article is interesting: https://www.nytimes.com/2017/12/28/nyregion/new-york-subway-construction-costs.html https://www.nytimes.com/2017/12/28/nyregion/new-york-subway-... "But while the Second Avenue Subway cost $2.5 billion a mile, the Line 14 extension is on track to cost $450 million a mile." (that price includes stations, emergency exits, rails and systems...)