It has been my experience -- which some more "keepin it real" journalism concurs with -- that New York's outlandish infrastructure costs, as well as the majority of the USA's public projects, are primarily due to two main agents:
1. White collar bureaucracy
2. Blue collar "bureaucracy"
Both parties -- and the multitude of agents that operate within them -- are all too able to align their "piece" of the project towards their own interests.
These interests very much involve time and money.
For money, it's simply rerouting costs. And for time, it's "making one's mark," by misallocating resources to personally-enriching matters, that do not benefit the project as a whole, and usually hinder it.
It's late, and I'm not at 100% to go into detail, but surely this is well-known already?