To clean up the background clutter, the newest subway map has eliminated some minor streets, Alphabet City.

Whenever I write about subway maps, my pieces or the comments that follow inevitably turn toward a debate on form vs. function. Should a subway map, I’ve wondered, aid riders navigate the city above or simply provide a more artistic schematic view of the train routes? Both views have their merits, and the best practical maps strike a balance between the two.

When the MTA issued a quiet revision to its map earlier this map, I noted how the MTA has moved toward a simplified map. As the authority said to me, “To continue to build on earlier clutter reduction, we’ve removed some streets and cemeteries that were not directly served by the subway.” It seems that the MTA’s approach is to overlay the subway routes on a rough outline of the city grid.

Earlier this week, Michael Grynbaum at The Times took a closer look at the map’s changes and found some interesting stories that illuminate the origins of the current map. Grynbaum picks Charlton St. in the West Village. I’ve lived in New York for my entire life, and I’d be hard-pressed to tell you where Charlton St. is. For some reason, though, it was, until recently, on the subway map.

Amusingly enough, not enough residents of Charlton St. noticed its presence on the subway map. “I never noticed that,” Richard Blodgett, president of the Charlton Street Block Association, said. “Maybe I’d seen it and not thought much about it. I’ve certainly never heard anybody in the neighborhood discuss that.” But now it’s gone, and Grynbaum recounts the story determining the streets that cracked the map:

Members of the design committee that created the map in the late 1970s recalled conversations with the tourism bureau and a survey of leading maps at the time. But the general approach was summed up by John Tauranac, the committee’s chairman: “A lot of it was seat of the pants.”

“The whole purpose of putting in what could be considered ancillary streets was to give people a hint of where they are in relation to subway stations,” Mr. Tauranac said. “My memory doesn’t serve me well enough to include whether there was discussion over whether to include Charlton, King or Vandam.”

Michael Hertz, who also sat on the committee, concurred. “Sometimes we put stuff down almost arbitrarily, if we thought we had room for it,” he said. As for Charlton, “We could have flipped a coin and put the next street in.” Personal preferences, Mr. Hertz said, had no bearing on the decision: “No one said, ‘I want that street in because my grandmother lives there.’”

As Grynbaum notes, Charlton St. isn’t the only one to draw the short straw in this redesign. As Grynbaum notes, in Manhattan, Greenwich St., Bank St., Madison St. and Avenues A, B and D are all a victim of the map cuts while Warren Ave., Laconia Ave. and Boston Road in the Bronx have met their demise. Brooklyn’s Third Ave. and Columbia St. are but a map memory, and 20th Ave. in Astoria and 59th St. in Queens are off the map.

On the latest version of the subway map, Astoria ends at Ditmas Boulevard.

The end result is something far easier to read. With fewer white lines distracting the viewer, the map draws more attention to the subway routes, and that, after all, is its primary purpose. At the same time, though, it becomes a less useful tool for those who want to use the map to navigate above ground as well. Does Astoria end with the subway map and the N and Q trains at Ditmars Boulevard? Is there even a New York Ave.? Is the next major street east of First Avenue simply the FDR Drive? Alphabet City, you are no more. Even Charlton St., the western part of Prince St. that once hosted exits from the IND’s Spring St. station, will fade from our cartographic memory.

The form vs. function battle is one the MTA has been waging with its subway maps since the days of Vingelli in 1972. Slowly, slowly, the authority is moving toward a representation with the outlines of the boroughs and only a handful of key streets. As the grid fades away, this new map is a-OK for subway navigation. Any use beyond that is sure to get the budding map-reader dazed and confused.

The MTA's Weekender map introduced a new generation of subway riders to the wonders of Massimo Vignelli's iconic subway map.

When the MTA debuted its Weekender map last month, it did so with a flourish. The new offering, a digital interpretation of the weekend’s service changes aimed at bringing visual information to the straphanging masses, brought Massimo Vignelli’s controversial and iconic subway map back into circulation.

Vignelli’s map, currently a part of MoMA’s permanent collection, had a decade-long run as the MTA’s official subway map in the 1970s, but it was a run not without constant controversy. Relying on a multitude of colors and some abstract geographic shapes that vaguely represented the boroughs of New York, the map had numerous detractors who found it hard to use and hard to read. Parks weren’t green; rivers weren’t blue; and due to the lines and angles, some stations weren’t even in the right place.

By the mid-1970s, the MTA had a plan in place to phase out the Vignelli map, and in 1979, the map designed by Michael Hertz Associates made its debut. With some modifications, that’s the map we know and begrudgingly love today. Yet, Vignelli’s map has always been a popular one. It’s appeared on sunglasses and dresses, and in 2008, Vignelli issued an update for Men’s Vogue.

Now, Vignelli’s offering is back in action with the MTA but just don’t call it a map. Rather, the Weekener is a diagram of subway service. Vignelli’s map, with its straight lines that each represent one subway route, is ideal for the digital age. As Vignelli told The Times a few wees ago, his map was “created in B.C. (before computer) for the A.C. (after computer) era.”

So just how did Massimo Vignelli and the MTA work out the new diagram? A post by Steven Heller on The Times’ T Magazine blog delves into the detente. Heller writes:

he new digital iteration is the result of the combined efforts of Vignelli and two of his associates, Beatriz Cifuentes and Yoshiki Waterhouse. One of their first acts was to rename the map. It is now a diagram, which actually makes sense as it is not a literal representation, but a semantic one. They also agreed to add supplementary neighborhood map options — online versions of the proprietary maps already used in M.T.A. stations.

For The Weekender, the team rebuilt the diagram geometry from scratch using a new primary grid for Midtown. This grid is essentially a square bound by 14th and 59th Streets, and Park and Eighth Avenues, with Broadway running diagonally from corner to corner. Intervals between major cross streets like 14th or 42nd were placed equidistantly along the grid, with more minor stops, like 18th and 28th, placed in between. And, Waterhouse adds, “We introduced a hollow dot to represent stops, which were sometimes passed, depending on schedule, known as a ‘sometimes-stop.’”

Waterhouse explains that all critiques of the 1972 map — which had been dutifully retained by the M.T.A. — were addressed. But Vignelli’s biggest bugaboo was showing the parks. He believed that including them — particularly Central Park — was the downfall of the 1972 map, so the new iteration eliminates all parks. Issues of type size and legibility were addressed, and line colors, station names and connections were all updated.

With Vignelli’s map making headlines, design enthusiasts have again expressed their hopes that the MTA would reissue it in paper form. Clearly, the diagram has retained its allure of yesteryear while offering up something nicer to look at than the current map. As a tool for navigation though, it still relies on basic knowledge of New York City geography and the streets above.

As a subway map buff, I own more than a few Vignelli maps of various vintages. I love the design and the decidedly 1970s approach to subway route colors. I also recognize that it wasn’t the most practical design in the world. With the Weekender, the Vignelli diagram serves its purposes, and while the technology behind the MTA’s offering may need some refining, the design is just right.