What's all this about?

While autonomous cars are a few years off yet, semi-autonomous driver assist systems are proliferating throughout the industry. And the 2016 Mercedes-Benz E-Class, which will be the fifth-generation model, is going to possess such software, this time in the form of Active Lane Change Assist (ALCA).

Is this to help out on motorways?

Yes, ALCA - part of the Drive Pilot package - uses radar- and camera-based technology to scan its surroundings. It can then automatically steer the Mercedes into the next lane if certain parameters are met.

And what are those parameters?

OK, the list runs like this: the indicator for the direction of the intended lane change (it works for overtakes and also for swinging back into the inside lane when required) has to have been on for more than two seconds; the unoccupied zone detection system allows a lane change within three seconds; Steering Pilot is activated; the E-Class has to be on a multilane, motorway-type road, detected via Comand Online's satnav module; a separate lane has to be picked up by the stereo camera; and the speed of the car must be between 50- and 112mph.

The unoccupied zone detection system...?

Forward- and rear-facing cameras constantly scan the road around the E-Class, to ensure there aren't any other cars in the vicinity. They also check to see if there's a car coming up fast in the overtaking lane, the ALCA software factoring in speed differentials to make sure it doesn't dim-wittedly pull out at the last second in front of another motor tanking along in the outside lane.

Has this system been approved for use?

In Mercedes' homeland of Germany, yes; for the rest of Europe, not quite yet, but Mercedes has already got the ball rolling on that score.

And can ALCA be overridden?

If any of the car's sensors detect an obstacle, or they can no longer pick up lane markings, or the driver counter-steers any steering input ALCA makes, or if Steering Pilot is switched off, then the automatic lane change won't take place. So the E-Class isn't taking over all driving duties just yet.