Yet flying cars have never taken off. That is not because they are impossible to build, but because they are, fundamentally, a compromise, neither good on the road nor graceful in the sky.
They are also inconvenient. Most designs require a runway to take off and land, and a pilot’s licence to operate. But that is changing. Developments in electric power, batteries and autonomous-flight systems have led to a boom in sales of small drone aircraft. Several entrepreneurs have had the idea of scaling up such machines to the point that people can fit inside them. The ultimate goal is a pilotless passenger drone that can either be parked outside your house like an ordinary car, or even summoned with a smartphone app, like a taxi.