Like the video phone call, the flying car was a promise that went undelivered for decades. And like the video phone, just when we all accepted we were probably better off without it anyway, along it comes.

If all goes well, the Transition, produced in Massachusetts by a US company called Terrafugia, may hit the market next year. It will not, however, provide you with an instant escape from traffic jams. The Transition's makers call it a "roadable aircraft", which means it's not so much a flying car as a plane you can drive. It still needs an airport to take off, but when you land the wings fold up and the petrol engine that drives the propeller engages the wheels. It's aimed at eliminating some of the difficulties faced by light aircraft pilots – you can still get where you're going in bad weather, and you can store the plane in your garage – but you couldn't call it a practical option: the Transition will retail for about £120,000. You can buy a plane and a car for a lot less.