NEW YORK (NYT NEWS SERVICE ).- New York City was on the brink of bankruptcy in the 1970s. Crime was on the rise, and subway ridership had dropped to its lowest level since 1918.

In 1979, responding to complaints from riders that the subway map was difficult to use, the Metropolitan Transportation Authority hired the Manhattan design firm, Michael Hertz and Associates, to create a new map.

The goal was to develop an accessible geographical map that would provide the information that commuters and tourists needed to navigate the city.

The Hertz firm’s map was digitized in 1998, with many of the design elements from the 1979 map incorporated into the new version.

The MTA subway map is a record of how graphic design, politics and geography have shaped the city over the last 40 years.

The primary designer assigned to the 1979 redesign, Nobuyuki Siraisi, was a trained sculptor and painter. He prepared for the task of representing the subway lines using an unconventional method.

He rode the length of every train line with his eyes closed, feeling the curve of each track and then drawing the path he perceived in his sketchbook.

Studies conducted by Arline Bronzaft, a psychologist, as part of the design process found that riders were disoriented by the straight lines on the previous map. Siraisi’s hand-drawn lines addressed the issue.

Siraisi assigned colors to trains to give them a way of being easily identified verbally. The designers also depicted the city’s land mass, bodies of water and parks in their natural colors, rather than using the existing map’s beige palette.

Susan Shaw, another designer at the Hertz firm, felt it was important that the map helped subway riders navigate the city when they were above ground. For example, she drew the shape of Central Park’s ponds accurately to help orient people traversing the park.

The geography of each borough was distorted to accommodate dense areas like Lower Manhattan and downtown Brooklyn where many train lines converge.

There is one borough, of course, that contains no subway lines: Staten Island, which was absent from the 1979 map except for a tip in the lower-left corner.

All of Staten Island, including the Staten Island Railway, was added to the map in 1998 as part of an effort to display all of the city’s rail services.

The 1979 map used an eclectic mix of typographical styles. More have been added over the past 40 years. The current map has over 20 font styles ranging in size, weight, color and letter-spacing.

One of the 1979 map’s innovations was the creation of a “trunk-based” system. Train lines that run parallel to one another — the 4, 5 and 6, for instance — were combined so that they shared a single “trunk” line.

The lines branched off from the trunk when their paths diverged. This technique simplified the map significantly. Express trains then branched off from the main line.

The black lines between stations on the map represented underground connections. Some of the connections did not exist when the subway was owned and operated by three separate companies. They were combined into a single system in 1942. (Some New Yorkers still refer to the subway lines by their original names: BMT, IND and IRT.)

When the map was digitized in 1998, the process introduced a few quirks. Street lines end abruptly and parks appeared to be quickly drawn, leaving what looks like a sliver of beach. Street names were inconsistent in lining up with the corresponding white lines.

In 2010, the bridge connecting Rikers Island jail complex was removed as part of a continuing effort to simplify the map.

There are only 10 buildings marked on the map. Four are on Staten Island; one is the New York Transit Museum in Brooklyn.

Over the past 40 years, the MTA map has become a record of the changing city. Its design has endured because of its ability to adapt to the eclectic city it serves.

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