A Range Rover Sport has completed the claimed first self-driving lap of one of the UK's most challenging road layouts – Coventry's notorious post-war ring road.

A prototype self-driving car handled the complex road, successfully changing lanes, merging with traffic and exiting junctions at the speed limit of 40mph.

The trial was part of the GBP20m government-funded project, UK Autodrive, which ends this month after three years. Jaguar Land Rover engineers had completed significant self-driving technology testing on closed tracks before heading onto public roads in Milton Keynes and Coventry.

The model was chosen for its performance and existing features, such as adaptive cruise control, and was modified to include additional navigation sensors, radar and lidar. Coupled with the UK Autodrive research, the vehicle can now autonomously handle roundabouts, traffic lights, pedestrians, cyclists and other vehicles on complicated roads. It can also park itself.

The 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.

"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," JLR said. 

Engineers have also developed connected features as part of UK Autodrive. The safety-enhancing and emission reducing technology use the internet to connect vehicles to each other and to infrastructure such as traffic lights.