Modern Paris owes its urban design, with its wide avenues and parks, to Napoleon III’s security concerns — he needed the ability to move troops and artillery against revolutionary mobs.
Modern America owes its suburban design, with its highways and parking lots, to Eisenhower’s security concerns — he needed the ability to move troops and evacuate civilians in case of World War III, and he needed American industry dispersed before such a war.
The Bulletin of the Atomic Scientists made this point early and often:
The dispersal — that is, defense-through-decentralization — of cities and industries has been urged in the Bulletin ever since 1946.
[...]
It has been stated often before, but cannot be emphasized often enough, that reduction of vulnerability of our cities to atomic attack is important not only to win a future war, but above all, to avoid it.
The 1919 Motor Transport Corps Convoy was a convoy of 82 trucks and automobiles sent from Washington, D.C. to San Francisco, CA to gauge the suitability of the nation’s road network for automobile transport.
Per WIkipedia, the “average for the 3,250 mile trip covered in 573.5 hours was 5.65 mph over the 56 travel days for an average of 10.24 hours per travel day”. It reported no paved roads between Illinois and Nevada. The convoy had to make numerous road and bridge repairs along the way.
The observer from the new U.S. Army Tank Corps was Major Dwight David Eisenhower (Breven Lieutenant Colonel). His report is reproduced here.