I somehow feel that Autonomous drones would be easier to build than Autonomous cars.

Benefits of Autonomous drones:

1. Do not need to deal other non autonomous devices while in flight. Cars needs to deal with human, other cars driven by humans.

2. Do not need to follow existing road traffic rules.

3. Lot of paths available. Cars are limited to existing roads. Drones can have a lot of flight paths.

I understand that there are other challenges - more energy required, less safe in case of an accident, flight regulations.

But still. It seems like if the technology is there, it would be an easier transition with Drones vs Cars.