Via: cuttingroomflaw:

The map of the New York subway system that featured in The Warriors was  replaced in the same year that the film was released, 1979.

The map seen in the film was designed by Massimo Vignelli and was first introduced by the Metropolitan Transport Authority in 1972.

“But many New Yorkers were outraged by what they saw as the misrepresentation of their city, while tourists struggled to relate Mr. Vignelli’s design to what they found above ground. In 1979, the M.T.A. bowed to public pressure by replacing his diagrammatic map with a geographical one.”

The Warriors themselves had a few things to say about Vignelli’s map:

AJAX: Figure out how many stops to the Union Square.

COCHISE: Hey c’mon man, that’s not a map for Rembrandt!

FOX: It’s alright, nobody can read these maps anyway.

Everyone’s a critic, even in the movies.