"New York's Lost Subways," with Jim O'Grady, the transportation reporter at WNYC radio and a contributor to Transportation Nation.

The New York City subway system has 842 miles of track, making it the largest in North America.  However, there's even more to it than riders see: dozens of tunnels and platforms that were either abandoned or were built but never used. They form a kind of ghost system and this visual presentation reveals how the city's transit ambitions have been both realized and thwarted.

WNYC reporter Jim O'Grady will talk about those lines and stations that never were--or were started and are now unused. Guided by an "urban explorer," he snuck into one of them deep under Brooklyn.  He'll also speak about creating an interactive online map that overlays these phantom lines and stations on top of the existing system. The map has been the most popular feature in the history of wnyc.org.