I'd just like one small change to cities. Sidewalk escalators/treadmill of varying speeds. It would make commutes so much easier, plus people could actually get

I'd just like one small change to cities. Sidewalk escalators/treadmill of varying speeds. It would make commutes so much easier, plus people could actually get some modicum of a workout while commuting. I mean, it worked on the Jetson's, right?