Driver assistance systems

The most common systems

• ABS: prevents the wheels from locking under braking – the vehicle stays steerable.
• ESP: brakes individual wheels to stabilise a skidding vehicle.
• Automatic emergency braking: brakes by itself when a collision threatens.
• Adaptive cruise control: maintains speed and the gap to the vehicle ahead.
• Lane keeping assist: corrects the line when the vehicle drifts.
• Blind spot warning: signals a vehicle in the area you cannot see.

ABS and ESP work permanently and without your involvement. The other systems are switched on and off – and must be understood to be useful.

The limits

No system can overcome the laws of physics. ABS does not shorten the braking distance on ice; ESP cannot recover an entry speed into a bend that was plainly excessive.

Sensors have limits of their own:

• Dirt, snow or heavy rain blind cameras and radar.
• Backlight and tunnels disturb optical recognition.
• Faded markings or roadworks confuse lane keeping.
• Narrow objects – cyclists, pedestrians from the side – are not always detected in time.

The risk of false security

The main danger is not technical but human: those who trust a system relax their attention. Studies of driver behaviour show this shifting of responsibility again and again.

Remember: however many systems are on board, you are driving and you are answerable. An assistance system is a safety net, not a pilot.