A FLYING car retailing for $227,000 could be on roads in a matter of months - and customers are already lining up to be the first to get their hands on one, its maker claims.

Just over a week ago, the Terrafugia Transition passed a significant milestone when it was cleared for takeoff by the US National Highway Safety Administration.

It's taken Terrafugia founder Carl Dietrich just five years to realise his dream, with some media outlets reporting that the Transition could now be on US roads by the end of next year.

Last year, the project was headed for trouble after authorities demanded design changes costing Terrafugia somewhere in the order of $18 million.

Fortunately, Mr Dietrich's company then won a $60 million contract with the US Defence Department to develop a flying Humvee.

Despite the fact the price of a single vehicle has been pushed to about $230,000 from the starting order price of $170,000, up to 100 customers have already paid a $10,000 deposit for a Transition.

The next stage for Terrafugia is global domination, with the first stop outside the US being Europe.

The Civil Aviation Authority told the UK's Daily Mail that the US clearance meant it would be "relatively easy" for the Transition to get clearance from the European Safety Agency, based in Cologne.

"The bulk of the work has already been done in the US," Jonathan Nicholson, of Britain's Civil Aviation Authority, said.

"Safety standards are very similar between there and Europe."

Terrafugia says more than 20 Britons have already expressed interest in owning a Transition.

The two-seat plane is made of carbon-fibre and aimed primarily at the US's 600-strong "fly-in" communities.

It can lift off from almost any long straight road and once in the air, has a top speed of 185km/h.

On landing, its wings fold up in 15 seconds, with power then routed to the rear wheels, giving it a top land speed of 100km/h and size dimensions equivalent to a large sedan.

"It's like a little Transformer," Mr Dietrich said.

The Transition will be available to those with a light-aircraft licence and requires as little as 20 hours' training to fly.