The interstate highway system was basically designed to facilitate the movement of nuclear bombs to SAC bases and missile facilities. Why are the highway overpass heights standardized?[1]
Your text here and the link you gave don't say the same thing.
As http://www.fhwa.dot.gov/interstate/interstatemyths.cfm#quest... comments, the interstate highway system was primarily civilian in naure. It was not "basically designed to facilitate the movement of nuclear bombs to SAC bases and missile facilities".
The link you gave says, "Besides the obvious economic reasons, one of Eisenhower’s goals was to improve national security". That does not imply that Eisenhower’s main goal was related to nuclear weapon transport, only that national security was one of multiple factors.
In any case, this sounds like an urban legend. Indeed, at Straight Dope's comment board, some people tried to investigate it, at http://boards.straightdope.com/sdmb/archive/index.php/t-2955... . The military needs to transport many things, including tanks. What evidence is there that missile specifically drove the need, vs. more general military transport requirements?
I say "missiles" because the SAC connection doesn't make sense. The size of nuclear weapons or their transport systems can't be the deciding factor. The Mark 6 nuclear bomb, at https://en.wikipedia.org/wiki/Mark_6_nuclear_bomb , was the main nuclear weapon in the early-1950s. It was much smaller than a tank, and shorter than most people. The Mark 17 and Mark 24, which were thermonuclear, were a bit bigger, but still less than two meters tall. See https://en.wikipedia.org/wiki/Mark_17_nuclear_bomb . The next generation of nuclear weapons were smaller still. By 1960 we had the W47, which was 18 inches/460 mm in diameter and 47 inches / 1,200 mm long.
The first US nuclear ballistic missile was the Atlas, first launched in 1957 and planning started in 1954. Construction for the interstate system was authorized by the Federal Aid Highway Act of 1956. It is possible, timing-wise, that the needs for the Atlas drove the size requirement for the US highway system. But it's tight, and it sounds unlikely.
For what it's worth, this image of a Minute Man II on transporter, http://www.nps.gov/parkhistory/online_books/mimi/images/fig1... , implies that it needs no more than 5 meters of clearance. The interstate system requires that a minimum of 4.9 m clearance (except in urban areas when there is an alternate interstate around the area), so it certainly seems like the Minute Man transporter was designed for the highway system. It's not clear that the highway system was designed for the needs of the missile system.
There are many urban legends about the US highway system, such as the false belief that it was designed as an alternative landing strip for SAC bombers. This means there's a higher evidentiary standard than normal for statements like yours.
[1] http://scm.ncsu.edu/scm-articles/article/a-brief-history-of-...