Lane departure warning (LDW): what is it and how does it work?

Lane departure warning (LDW) systems warn the driver if he or she leaves a marked lane without using the indicator, or if the vehicle is drifting out of its travel lane.

LDW is part of the ‘second wave’ of active safety measures – using cutting-edge technology such as on-board sensors, radar, cameras, GPS and lasers – that is being fitted to passenger cars.

Active safety technology can prevent accidents from happening altogether or at least actively help the driver to reduce the impact of an emergency situation. Active systems give the driver more control in dangerous situations. To that end, various safety systems constantly monitor the performance and surroundings of a vehicle.

Simply put, active safety systems avoid or mitigate an accident pre-impact – so before it happens or contact is made.