31. City Expressways
- Chances We’ll See It: Low to Medium
The great Isaac Asimov wrote Robots & Earth books that involve one of the most interesting yet useful science fiction inventions ever. Called “City Expressways,” they work a lot like those airport walkways you see today. They are glass-walled and work on a railed moving strip. They move at speeds of 60 MPH and higher, allowing you to get to places faster.

You can step on or off of them at any point by jumping through a series of parallel strips that will accelerate or decelerate your speed. This is technically possible as we already have things like treadmills that can reach high speeds. The speed is not the hard part, it’s the jumping on and off that is difficult to do. The only way for this to be possible today is to remove that portion of the invention.