Putting driverless cars on the road safely is hard enough. Doing it in the air is much more difficult.
With further technology required and practical uncertainties, time is running out for them to be useful in the fight against climate change.
CASA says we could have flying taxis operating in Australia within five years. But there are a few hurdles to clear before we see ride sharing happening in the air rather than on the ground.
Flying cars have been the stuff of science fiction for years, and now companies are now starting to look at such options. But what will it take to get our cars off the ground?
Hoverboards, self-fitting jackets, nuclear fusion generators.... Some of Back to the Future's wacky inventions are closer to reality than you might think.
Despite futuristic predictions, planes, cars and trains haven't changed much for decades.