But there were actually all sorts of concerted efforts to stop the bulldozers in those days; and what's more, these freeway revolts even succeeded on occasion, as discussed at Greater Greater Washington. See, for instance, this plan to thoroughly cross-hatch San Francisco with freeways. In the face of public pressure, which began as early as 1955, more than 80% of these roads never got built:
In fact, San Francisco continues to tear down what freeways it does have within its city limits; its the only major city to lose freeway miles since 1990.
There was a major plan to build an inner ring in Boston, too:
Public opposition put the kibosh on that one in the early seventies. (The only portion of the plan that was completed - the Central Artery - became a notorious eyesore, and was itself demolished in the nineties and re-built underground in a project known as the Big Dig, which project was itself an enormous debacle for all sorts of reasons. So you see that the original freeway plan set off a sort of catalytic chain of fiascos.)
Other places weren't so fortunate; in Houston, among many other cities, an inner ring was built around the central business district, coincidentally enough running right through some of the city's most historic black neighborhoods. Funny how that always seemed to happen with these freeway plans. Though even some minority neighborhoods mounted successful efforts to fight off the highwaymen, even in Houston itself, where the Harrisburg Freeway, which would have bisected the city's mostly Hispanic East End was scuttled. And the campaign in Washington, DC that spawned this announcement was also a success:
Jane Jacobs led the fight against freeways in New York, though her great urbanist screed, The Death and Life of Great American Cities,wasn't published until 1961, and the tide didn't turn against Robert Moses & co.'s freeway plans for NYC until they had mostly been enacted. Only the finishing touches on the city's freeway sytem - the dashed lines in the map below, plus the Lower Manhattan Freeway that would have obliterated most of SoHo and the Lower East Side - were halted.
Despite Moses' success in re-building the city as a place for cars rather than people, New York is still the most thoroughgoingly urban city in North America, with the largest and arguably most successful public transit system. That is either a testament to New York's resilience in the face of efforts to re-shape it, or an indictment of the rest of America's cities for failing to provide successful urban environments for their people.
UPDATE: A commenter links to a map of Portland's thwarted freeways. The city, which had commissioned none other than Robert Moses to design its highway plan, was definitely at the vanguard of the freeway revolt movement. The author of that post makes a good point:
We’re lucky to have escaped the fate of many other cities — but I hope we are not getting ready, with the Columbia River Crossing project and all the stimulus spending in our near future, to make some of the same mistakes that we avoided forty years ago.