Lane Departure Warning (LDWS) and Lane Keep Assist (LKA)


The Lane Departure Warning System and Lane Keep Assist are features designed to help you stay in your lane. When used correctly, they can prevent some accidents occurring when a driver is not steering properly. This would commonly be in situations of distracted driving or driver fatigue.

**See re-calibration warning at the bottom of this page**

Lane Departure vs. Lane Keep

There is often confusion about the distinction between these two features. This is understandable because manufacturers are quite inconsistent in what name they use. A brief history will help.

Lane Departure Warning launched as a new feature years ago that involved a camera watching for lines on the road in front of your vehicle. If it detected you drifting without using a signal light, it would warn you by beeping, flashing, vibrating, or any combination of these.

Then, later on, this was evolved into Lane Keep Assist which uses the same camera and line tracking technology, except now in addition to warning you if you are drifting out of your lane, it will actually attempt to steer your vehicle back into the lane for you. This is also obviously also a key component in self driving vehicles or cars with hands free cruise control.

Where it can confuse people is that in recent years, many manufacturers have stopped referring to these as distinct features. Some no longer offer a warning-only edition and have taken to referring the full package of warning and steering assistance as simply “Lane Departure Warning System”.

Confusing right?

The good news is that it isn’t hard to work out what you have.

  • If your vehicle only warns you and doesn’t correct the steering for you, pick Lane Departure Warning every time.
  • If you are looking for a new windshield and you know your car steers you back into your lane, just select the most correct option when getting a quote. If Lane Keep Assist is listed, pick that. If only Lane Departure Warning is listed, then they’ve combined them and you can just select that option.
  • More often than not they aren’t even different windshields anyways (remember, they use the same camera technology).
Ford Flex image obtained under creative commons license: https://commons.wikimedia.org/wiki/File:Lane_Departure_Warning.jpg

Re-CalibrationAn important notice

Both LDWS and LKA are “Advanced Driver Assistance Systems” (ADAS).

Most manufacturers require these features to be re-calibrated after a new windshield has been installed. It is your responsibility to ensure this has been completed either by the auto glass facility you are having the windshield replaced, or at a dealership. Every vehicle is different so consult your manufacturer and local glass expert for more information.

Windshield Surgeons Auto Glass and affiliates accepts no liability for ADAS related features. As a driver it is ultimately your responsiblity to stay safe and attentive while driving as well as ensure you have your vehicle serviced back to original specifications properly.

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