While failing to cater to the public’s needs, its colored linear motif nonetheless clearly and rationally conveyed the fundamental distinction of which subway line is which. By simplifying the geographical details, the map may have looked less like a conventional map and more like an electrical schematic, but it forced the eye to see only the essentials. Maybe it was ahead of its time. Or maybe it was right on time — but the public failed to recognize it.

Its replacement in 1979, a more traditional topographical version, reintroduced all the basic map conventions (including blue water) and, most important, the New York City street grid. Yet the circulatory look of the map not only lacked the aesthetic flair of the Vignelli classic, it also junked up the graphical way-finding composition by reintroducing thinner and more serpentine route lines and a mass of smaller landmark details. Making Manhattan and the boroughs more representational probably helped users recognize their locales and destinations, but it also injected a labored look to the entire document.

The revision in 1998 added even more information, including free transfer points and alternate bus service, but once again reduced the size of the colored lines and route numbers. Users adapt to almost anything over time, and adjusting to the more cluttered composition was no exception. But that should not be the determinant of good design. While the Vignelli map may not have been the most versatile or adjustable given changes in the subway system, the ’79 and ’98 maps did not solve any of the aesthetic woes.

The newly revised, resized, recolored and simplified map does indeed reduce the level of visual noise to a more tolerable level. The brighter colors — the water is bluer and the boroughs are a pinch less dark — provide a more cheerful look. Shortening the typographic dimensions of the pop-up boxes of additional information makes navigation a little less daunting. Putting Manhattan on steroids relieves the linear congestion and allows the graphic elements to breathe. Even adding the blue reservoir to Central Park allows the eye to focus better. So what’s not to like about the new iteration?

Like those for Paris and London, New York’s subway map is a design touchstone. Harry Beck’s first diagrammatic map designed in 1931 for the London Underground will go down in history for its graphical ingenuity — and the Tube’s forward thinking. The diagrammatic maps for the Paris Métropolitain exemplify functional design thinking.