In 1929, New York City decided to build a subway line along Second Avenue at a cost of $1.3 billion in 2012 dollars. It’s due to be completed in 2016 at a cost of some $17 billion.

Why so expensive? Why so slow? Because it’s being built in America. (Not that they had much choice on that.)

The cavern that will someday be the 72nd Street station on the T line. (Photo by the Metropolitan Transit Authority.)

In a piece at Bloomberg, Stephen Smith explains why American mass transit is so much more expensive than elsewhere in the world. In short: the powerful and unaccountable private contractors, a trend toward extravagant station design, a failure to demand quick timelines, and a surfeit of consultants.

This will not be news to the good folks working on the subway line. In February, the federal government announced that the first stretch of the subway line would indeed be going over budget, and would take a year longer than expected.

But at least New Yorkers can be confident in the quality of the work.