Apparantly a near tripling of the population and substantial advances in automotive technology had nothing to do with this.
The corollary to this is the idea that if you don't build roads you won't get development ~ this was tried in both San Diego county in California and Fairfax county in Virginia.
They both got massive growth, without sufficient roads!
As president he saw that although improved, the roads were still inadequate so the Interstate highway system was born. Did you know that some of the roads were fashioned as secondary landing strips for aircraft including B-47s and BUFs? One of the modifying specs occurred in the late 50s when Atlas, Thor and Jupiter missiles were being manufactured in the Western US and then missiles were hauled on special truck beds to Cape Canaveral. Drivers reported that certain detours were needed to circumvent overpasses under which the missile carrier couldn't fit. Thus bridges were/are marked and as new bridges are built the trucking industry finds life easier.
Much as *I liked Ike,* and have loved to drive the Interstates, the Rte66er in me needs to say "harrumph" for killing off many of the Main Street USA characteristics of small towns.
If you've gotten off the freeway at one frontage road conglomeration of gas stations and fast food franchises, you've exited at "them all." Or "the Mall" - same thing.
*sigh* Byways and bygones.