The device uses a radar sensor and powerful microcomputer to measure the relative speed and distance between the two vehicles and, if necessary, it will slow the engine or apply the brakes. The electronics then bring the vehicle back to the required speed once more - all without intervention from the driver.

The system is likely to be in production in the next few years and will operate in a speed band between 20 and 90 mph. Called the Autonomous Intelligent Cruise Control the device will join a host of other Mercedes inventions including ABS brakes, ASR (anti-skid control), ETS (electronic traction system) and ESP (electronic stability program).