If I remember my history (but sure it has changed) President Eisenhower initiated the Interstate system based on what he saw in Germany after WWII ... so now I guess it’s the states that control it and can do what they want which I think is not what he had intended ....
Eisenhower was influenced by the Autobahns, but the roots of the Interstate system go back to the late 30’s in the US. The states have always owned and operated them from the passage of the Federal Aid Highway act back in the 50’s.