New York, NY Times, 12/28/17:
The Most Expensive Mile of Subway Track on Earth
An accountant discovered the discrepancy while reviewing the budget for new train platforms under Grand Central Terminal in Manhattan.
The budget showed that 900 workers were being paid to dig caverns for the platforms as part of a 3.5-mile tunnel connecting the historic station to the Long Island Rail Road. But the accountant could only identify about 700 jobs that needed to be done, according to three project supervisors. Officials could not find any reason for the other 200 people to be there.
It's underground trackage but obviously it's not really "subway" in terms of the rail rapid transit in New York since this will be LIRR.