BusinessLong-delayed New York subway line opensTo view this video please enable JavaScript, and consider upgrading to a web browser that supports HTML5 videoBusinessLars Halter01/02/2017January 2, 2017It's costing a whopping $1.7bn per kilometer. But now the first phase of New York's Second Avenue Subway has opened after a century of planning.https://p.dw.com/p/2V8fHAdvertisement