What is lane-departure warning?

  • How does it work and will it benefit me?
  • Which cars is it available on?
  • Parkers explains the tech

Lane-departure warning is a safety system that alerts the driver if it detects the vehicle unintentionally straying out of lane.

How does lane-departure warning work?

A small camera or sensor – usually mounted at the top of the windscreen behind the rear-view mirror – detects if the driver is unintentionally allowing the vehicle to stray out of its lane.

It will then either sound an audible warning or vibrate the steering wheel (in some cases both) in order to alert the driver. Most systems will only work above a certain speed.

Note that if the respective indicator has been switched on the system should not sound a warning. Almost all cars fitted with lane-departure warning technology allow the driver to switch the system on and off depending on their preference.

Do I need it?

Lane-departure warning technology can be very useful should you cover many motorway miles, though town drivers will likely see little benefit.

Found on

The technology is now available on a wide range of cars such as the Ford FocusMazda 2 and Nissan Qashqai.

Similar to

Be careful not to confuse lane-departure warning with active lane assist or active lane keeping assist technology. The latter two refer to systems that, instead of alerting the driver to an unintentional lane change, will attempt to automatically steer the car within its lane.

It’s more expensive and isn’t available on as many cars, yet should become more common as the technology is rolled out.

Click here to read more about active lane-keeping technology.

Looking for more jargon-busting motoring meanings? Head over to our Parkers Car Glossary page and take a look at our other definitions