Lane Departure Warning System (LDW)

Lane Departure Warning System (LDW) is an advanced driver assistance system that is available in many newer vehicles. The main objective of this technology is to warn the driver if they unexpectedly leave their lane in the vehicle.


LDW can potentially reduce the risk of an accident by 11%. This technology is becoming increasingly common in the automotive market. 


The Lane Departure Warning System uses cameras mounted on the windshield near the rearview mirror. The cameras monitor the lane markings. If the vehicle starts to move out of the marked lane when the turn signal is off, the system warns the driver. The lane departure warning can be an audible signal, an indicator on the instrument panel, or a vibration of the seat or steering wheel. 


In order for the system to work correctly and for the car to see the lane it is driving in, the LDW sensors need to be calibrated. 


For proper static calibration, you must have:


  • An open space measuring 30 x 50 feet
  • A leveled, clean floor
  • A uniform, neutral color on the walls and floor
  • Uniform and adjustable lighting
  • Unobstructed space around the vehicle
  • No reflective surfaces
  • No glare on the windshield
  • No direct sunlight


Dynamic calibration requires: 


  • Scanning tool
  • Alignment stand
  • Calibration tool 
  • Aiming at targets. Some vehicles use a single target, while others use multiple targets. Many targets look like enlarged black-and-white patterns, while radar targets may be shaped like a metal pyramid, reflective or metal plate.
  • Measuring tapes or laser measuring devices are mandatory. 


However, no system works perfectly. Lane Departure Warning System works less effectively in rain or snow. It also turns off when visibility is limited. Obviously, it doesn't work when the road is covered with snow or there are no markings at all. LDW also works worse if the lane markings are outdated or if the lane markings are rough.