In the first decades of the 20th century, New York City experienced an unprecedented infrastructure boom. Iconic bridges, opulent railway terminals, and much of what was then the world’s largest underground and rapid transit network were constructed in just 20 years. Indeed, that subway system grew from a single line in 1904 to a network hundreds of miles long by the 1920s. It spread rapidly into undeveloped land across upper Manhattan and the outer boroughs, bringing a wave of apartment houses alongside.
Then it stopped. Since December 16, 1940, New York has not opened another new subway line, aside from a handful of small extensions and connections. Unlike most other great cities, New York’s rapid transit system remains frozen in time: Commuters on their iPhones are standing in stations scarcely changed from nearly 80 years ago.