The World Trade Center Transportation Hub is going to end up being almost twice as much as was predicted in 2004. The cost has reached almost $4 billion and of that, $655 million was spent on construction management: supervision, documentation, monitoring, and inspection. The hub will not only serve as station for an average of 46,000 commuters (many from New Jersey), but also as a high-priced shopping mall.

The soaring budget has been blamed on much more than the extravagant and expensive work of architect Santiago Calatrava. After reviewing hundreds of documents and conducting dozens of interviews, a report was published that determined that the cost overruns were caused by pushback and demands from politicians as well as the Port Authority’s poor management of private contractors and of the project in its entirety.

“How Cost of Train Station at World Trade Center Swelled to $4 Billion,” in The New York Times explains the politics and history behind this monumental construction project and contains some great photos and interactive diagrams.