Paul Rudolph's study, commissioned in 1967 at the behest of the Ford Foundation, was the last death rattle of an idea whose future had already been decided—Robert Moses' "meat axe" through Lower Manhattan, dulled by public opinion, litigation, and cost, already on the wane by the late 1960s, was finally killed in 1971.
When published in 1974, the plan by Rudolph, known for, among other things, his Brutalist works at Yale University, was not part of any vital public debate—the New York Times (based on my search of its archives) didn't mention it until 1979—but a mere curiosity of architectural speculation; "we are not saying this is the way it must be," read the script for a short film accompanying the project. "We are saying that this is one way it could be, these are the systems that now feel will be the best for x number more automobiles and people."
Although the plan may now seem the height of hubris, some paleo-modernist fantasy of speed, circulation, and megastructural scale—one that, as a Cooper Union official told me, evokes negative reactions from virtually every visitor—Rudolph (who, after all, marched with Jane Jacobs in the futile effort to save the old Penn Station), was clearly wrestling with the idea of fusing the automobile and the city in a sensitive, contextual way. "This plan," reads the script for a promotional film on the project, "does not propose to tear down everything in site; it suggests that we tear down as little as possible."
The plan does not lack for architectural bravado; the modular pyramids of housing over the highway evoke Kisho Kurokawa by way of Disneyworld. (Rudoph, the curators note, may have been inspired by Disney's "monorail" hotel.)
And the anti-urban "HUB" at the center, a parking-and-plazas complex, looks like some alien Roomba, sucking up street life. But the plan is filled with unresolved contradictions. While Rudolph downplayed the noise and other externalities of a bifurcating highway trench, it undoubtedly would have dampened street vitality (and real estate prices) on its edges. And given the vast amounts of space devoted to parking in the soaring apartment towers lining the Williamsburg Bridge approach, one suspects the promised traffic improvements—the streets of the model are conspicuously filled by only a few cars—would simply have been filled anew with the influx of new car-owning residents.