Despite the Interstate Highway areas that have been ill-maintained (not Ike's fault), this system has enabled Americans to be the most mobile citizenry on the planet - in a continent-sized country, no less.
Americans don't really like to be herded aboard trains (like the Europeans), we like to get in our own autos and drive, baby. Freedom!
Ike’s considerations for building the Interstate were military, to have the ability to quickly move troops and armor in case of invasion.