John Levine wrote:

Movement of tanks.

The DOT's interstate highway web site disagrees with you. Eisenhower
was certainly a big supporter, having seen how well Hitler's autobahns
worked, but the origins of the plan bo back to 1939 and it was
partially authorized by 1947:

http://www.fhwa.dot.gov/interstate/interstatemyths.htm
http://en.wikipedia.org/wiki/Interst...ystem#Planning

Don't forget that Interstate-style highways were hardly unknown in
1956. The PA Turnpike was authorized in 1937 and parts were open in
1940 (with no speed limit, descreased to 70 mph in 1941, wheee.) The
NJ Turnpike was authorized in 1948 and opened in 1952. The NY Thruway
was authorized in 1950 and opened in 1954.

They also disconfirm the myth about straight places to be used as runways.

I've got to agree with John Levine. By that time, Moses' boys were already
influential in the Bureau of Public Roads and other federal agencies that
became FHwA, and had been guiding federal policy for a long time.