Most recent NY trackage

Expounding on nscalejim's post, here's Wikipedia on the Oak Point Link, and in case there's any doubt, that's $90MM per mile!:

The Oak Point Link is a 1.9-mile (3.1 km) long railroad line in the Bronx, New York City, USA, along the east bank of the Harlem River.[1] It connects the Metro-North Railroad's Hudson Line (on the Spuyten Duyvil and Port Morris Railroad section) with the Harlem River Yard and the CSX Transportation Oak Point Yard at the north end of the Hell Gate Bridge.

The line, constructed and owned by the State of New York, opened in 1998 to allow better freight rail access to the city by eliminating a more circuitous route that crossed busy commuter lines and whose tight turns (at Mott Haven and Melrose) limited the length of freight cars. The new line was built with loading gauge clearances high enough for trailer-on-flat car (TOFC) intermodal freight transport service, but is not high enough for double stack container service, due to limits imposed by city bridges crossing over the line and the high tides on the Harlem River.[2] Construction of the line began in 1983 and cost $187 million to complete.[1]

With regards to Oak Point Link, the FGLK spur to Guardian Glass in Geneva is around the same age. I guess it would come down to which line was built last.

Both are great examples. Thanks!

The very first condition imposed by the OP is that industrial spurs do not count (unless they are several miles long). That in no way describes the Guardian siding (which does not even belong to FGLK, but to Guardian). Using that measure, the line to new new salt mine would qualify, while a relatively short few tracks at the glass plant would not.

Fair points on the Guardian Glass Spur- I'd assumed more of the trackage was new than is the actual case. (Part of what I thought was new ROW is actually the Auburn Road, which has been around for about 170 years.) Thanks for the information.

And I agree that the R&S spur should count... because it's a couple of miles long.