Almost all of them have one thing in common, however: people can't ride in them. We say "almost all," as there is one exception. Ehang's 184 AAV (Autonomous Aerial Vehicle) is designed to carry a single human passenger, autonomously flying them from one location to another.

Ehang CEO Huazhi Hu began designing the one-seater electric drone a couple of years ago, after two of his pilot friends were killed in plane crashes. He decided that people needed a form of short-to-medium-distance personal air transport that didn't require them to have a pilot's license, and that took much of the danger out of low-altitude flight.

The idea behind the Chinese-built 184 is that users will simply get in, power it up, select their destination using a 12-inch touchscreen tablet display, then press the "take-off" button.