Devizes MP and transport minister Claire Perry took part in the unveiling of driverless vehicles in Greenwich today - one of the areas at which three-year trials is taking place.

The other test areas will be in Bristol, Coventry and Milton Keynes.

Today's launch follows publication of a Government review that reveals there is no legal barrier to the testing of automated vehicles on public roads.

But it could be some years before driverless cars are a feature on the streets.

First, the Government will publish a code of practice this spring for those wishing to test driverless vehicles on UK roads.

And it will be summer 2017 before domestic regulations are reviewed and amended to accommodate the new technology.

It will not be until the end of 2018 that international regulations are likely to be amended.

A survey has revealed that 48% of people would be unwilling to be a passenger in a driverless car.

The poll, for price comparison site uSwitch.com, also showed that 43% would not trust a car to drive safely without a driver and 16% were "horrified" by the whole concept.

In addition, 35% expected the introduction of driverless cars to push up their insurance premiums.

The poll suggests that politicians and innovators could face a tough challenge in enlisting public support for driverless vehicles.

Domestic changes could see alterations to the MOT test and also a possible revision of the Highway Code while he Government has also said there needs to be greater certainty around criminal and civil liability in the event of a driverless vehicle being in a collision.

In addition, the Government will consider whether a higher standard of "driving" should be demanded of automated vehicles than would be expected of a conventional driver.

The average driver in England spends 235 hours driving every year - the equivalent of six working weeks.

The new technology will mean drivers will be able to choose whether they want to be in control or hand the task of driving over to the vehicle itself.

This would let motorists get on with other things while the car did the driving.

For the purposes of the trials, driverless cars will still have a fully-qualified driver ready to take over active control if necessary.

At Greenwich today, in the shadow of the O2 Arena, Business Secretary Vince Cable and Transport Minister Claire Perry took a ride in one of the test vehicles - a Meridian shuttle.

It resembles a giant gold buggy and can go backwards and forwards without having to turn around.

Stepping off the shuttle after a short ride, Mr Cable declared: "Driverless vehicles are potentially the transport of the future in terms of road safety and congestion easing.

"The UK can be world leaders in this type of automation."

Ms Perry said: "Around 93% of road accidents are caused by driver error. Driverless vehicles will free up people's time. The whole project is incredibly exciting."

While at Greenwich, the two ministers also inspected two other automated vehicles which will be used in the trials which have been funded with £19 million of Government money.

One vehicle was a BAE Wildcat vehicle developed by aerospace company BAE Systems, which will be trialled in Bristol and is being used to test a range of functions.

One of the accessories in this vehicle is a CycleEye which can detect cyclists when they have gone into a driver's blind spot.

The other vehicle was a driverless pod with room for a "driver" and passenger which will begin trials in Milton Keynes this summer.

The pod is designed to run on a dedicated route on the pavement. Battery-driven, it has a 40-mile range and can travel at 15mph.