Propellor monorail?

People of the past loved looking forward to the future and all that it would bring. There were so many new ideas Back Then—like paving the Hudson, draining the East River, and bringing moving sidewalks, sub streets, and an aerotropolis to our urban landscape. So much ingenuity at work! Why aren't we The Jetsons by now?

In the below video, the people of the 1920s predict what will happen through the coming decades, all the way up to the 2000s—in fashion, women will wear PANTS, and men will carry around telephones! And as for our city: "Streets and buildings [will be] harmoniously related. Structural ingenuity would of course go on producing unusual forms. Suspension bridge apartment houses [will] gratify the human desire for novelty and romance"... and we'll rip apart our great architecture and everything will be luxuriously homogeneous.