For fun. Above was an ad campaign by Timken-Detroit Axle (founded in Detroit in 1909).
A dominent parts supplier in the early auto industry. Actually a fascinating story, intersects with Rockwell and other venerable American industrial names.
Anyway, in early 1940s, Timken Detroit Axle was a mega supplier who main products (axles, bearings, etc)were relatively UNSEEN by the average customer of the things IN WHICH they appeared.
So, they decided to advertise what kind of future their products would enable. None of this stuff showed up looking like these illustrations but Timken, Rockwell, et.al., and successors under different names, are still around today.
Some of the illustrations: SUPER-TRANSPORT ON SUPER-HIGHWAYS | flying-cars