LONDON — Get ready to stare in amazement as a car with no one behind the wheel passes by you.

Well almost no one.

The UK Department of Transport announced Wednesday that it has approved the testing of driverless cars on public roads with trials due to get under way by summer, however a qualified driver will be present in vehicles during the trial period.

Testing of driverless cars has already been taking place in the UK, but until now it had been restricted to off-road activities. That's set to change after a review by the department found there were no legal barriers blocking the move to public roads.

Another prototype unveiled by the Department of Transport. Image: Flickr, Department of Transport

Prototypes, not dissimilar to a golf-cart, were also unveiled and Milton Keynes, Greenwich, Bristol and Coventry were named as the four cities where the vehicles will be tested.

A code of practice for driverless cars will be published in spring.

The British government is keen to become a leader in an industry, estimated to be worth £900 billion in ten year's time. It hopes Wednesday's announcement will encourage manufacturers to locate in the UK to develop and test.

California has been testing driverless cars on its public roads since 2012 when it published a framework for autonomous vehicles on its state roads and highways. Florida and Nevada also allow testing on their roads.

Driverless cars are not without their critics in the UK. Last year, Britain's Institute of Engineering and Technology warned that they could be vulnerable to hacking attacks.

The IET warned software had to become more reliable before the public could have confidence in the vehicles.