Frere-Jones' inspiration for the typeface came from time spent walking block-by-block through Manhattan with a camera to find source material, and he based the font on the lettering seen in older buildings, especially the sign on the Eighth Avenue façade of the Port Authority Bus Terminal. "I suppose there's a hidden personal agenda in the design," Frere-Jones said, "to preserve those old pieces of New York that could be wiped out before they're appreciated. Having grown up here, I was always fond of the 'old' New York and its lettering."

The lettering that inspired this typeface originated from the style of 1920s era sans-serifs like Futura, where "Type, like architecture, like the organization of society itself, was to be reduced to its bare, efficient essentials, rid of undesirable, local or ethnic elements." This theme was found frequently in Depression-era type in both North America and Europe, particularly Germany. This simplification of type is characterized by Frere-Jones as "not the kind of letter a type designer would make. It's the kind of letter an engineer would make. It was born outside the type design in some other world and has a very distinct flavor from that."

source: typography.com