(Pocket-lint) - Jaguar Land Rover's autonomous Range Rover Sport has completed a lap of one of the UK's "most challenging road layouts". It self-drove around the infamous Coventry Ring Road, changing lanes, merging with traffic and exiting junctions at the speed limit of 40mph.

It is a significant step for the future of self-driving vehicles, and followed numerous tests on closed roads beforehand.

The trial was part of the governmentally funded project, UK Autodrive, and the Range Rover Sport was chosen as the vehicle already comes with some automated features - such as adaptive cruise control.

It was then adapted to also include navigation sensors, radar and lidar (laser guided radar).

This enabled it to autonomously handle roundabouts, traffic lights, pedestrians, cyclists and other traffic. And it can park itself.

"The Coventry Ring Road is known for its complicated slip roads and exits. It makes for very challenging conditions, especially when under pressure in the rush hour," explained Mark Cund, Jaguar Land Rover's manager of autonomous vehicle research.

"Our self-driving car is not impacted by the same pressure, frustrations or fatigue that a driver may experience and so it’s capable of turning a potentially very stressful situation into a completely stress-free one."

There is no timescale on when such a vehicle might become a consumer product, but this is an important step in that ultimate goal.

Writing by Rik Henderson.