I'm reading this article, and it says:
Postwar suburbanization and the expansion of transportation networks are occasionally overlooked, but weirdly crucial facets of the military-industrial complex. While suburbs were largely marketed to the public via barely concealed racism and the appeal of manicured “natural” landscapes, suburban sprawl’s dispersal of populations also meant increased likelihood of survival in the case of nuclear attack. Highways both facilitated suburbs and supported the movement of ground troops across the continental United States, should they need to defend it (lest we forget that the legislation that funded much of the U.S. highway system was called the National Interstate and Defense Highways Act of 1956).
It seems to suggest that the Cold War-era U.S. Government encouraged people to move to the suburbs and built highways, in part because it would mean that not so much of our population would die due to nuclear attacks on our cities.
Is there any truth to this? Is it even possible to know?
I've never found any evidence suggesting it did.
Kathleen Tobin has written an article claiming that policymakers' fears of atomic attack was a significant factor in population dispersal. I find it to be an astonishing piece of rhetorical sleight-of-hand, using a few magazine articles discussing the concept of dispersion to prove that it was federal policy—despite the absence of a single federal law or regulation on the subject.
As for the role of Interstate highways, those were proposed long before the Cold War, and throughout the years of congressional debate, military strategists repeatedly testified that they didn't need any particular routes or geometric specifications, always saying that highways built to promote commerce would also serve their needs. To Pres. Eisenhower, the public-works and job-creation aspects of the system were about as important as defense aspects. I am not aware of any serious civil defense or military rationale that was part of Congressional debate. The words "and Defense" were added to the name of the "National System of Interstate Highways" in conference committee, almost as an afterthought, and played no role in congressional voting. See Congressional Record 102, Part 8, pp. 10991-10997. The definitive source on this history is Rose, Mark H. Interstate: Express Highway Politics, 1939-1989.
There were definitely a lot of government discussion about the value of dispersion, from the point of view of civil defense (ameliorating damage from a nuclear attack). An article that discusses them in some detail is Peter Galison's "War Against the Center" (2006). In the 1950s, for example, the Bureau of Commerce directed planners in metropolitan areas to move new industry outside of city centers. Project East River, in 1952, studied the problems of dispersion specifically as civil defense issues, and the ways in which you could encourage it to happen (e.g. by making it a consideration in federal loans, insurance, and contracts). There were also some cases of specific federal agencies (like the Atomic Energy Commission) having their headquarters being located outside of assumed target areas (in this case, the AEC was moved to Germantown, MD, rather than Washington, DC). Apparently there were some tax incentives put into place for moving industry out of prime metro areas in the early-to-mid 1950s.
So there was urging, there was planning, there were many pamphlets and studies. Is this why dispersion and suburbanization actually happened? That, I think, is a harder argument to make. There are lots of other reasons (economic and social) that can be more directly attributed to those movements. I am not sure (and Galison's article does not indicate) whether these more heavy-handed inducements (other than the aforementioned tax benefits) actually were put into place.