How does that lane deviation system work on my new car?

It is called LDWS or Lane Departure Warning System. It was new to me too, when we traded in a 2018 Dodge Caravan for a 2024 Chrysler Pacific. We’re very happy with the new car and surprised at all the new auto technologies that were developed in just six years.

The LDWS is designed to warn a driver when the car begins to move out of its lane on a freeway or limited-access highway. A limited-access highway is usually a four lane highway, but does not necessarily have on-off ramps and can be accessed by turn-offs and intersecting roads. In any case, for LDWS to work properly, there must be that white stripe on the right side edge of the driving lane or white broken line on the left side. The system does not work when the edge of the lane is not marked by a painted line.

There are several versions. Lane departure warning (LDW) systems warn the driver the car is leaving its lane. The driver gets a visual, audible, and/or vibration warning. Lane keeping assist (LKA) gives the driver a warning and automatically turns the steering wheel for correction. That is what our Chrysler Pacific has. The Chrysler people call it “LaneSense.” Lane centering assist (LCA) systems keeps the car centered in the lane, and after two or three “assists” a loud audio warning is given to the driver. My vehicle will flash a warning on the LCD display, “Lane departure detected. Keep hands on wheel.” The LaneSense system is operational between 37 and 112 mph. Our car also has adaptive cruise control to prevent rear end collisions. My car is smarter than I am!

Various systems use video sensors mounted on the front of the car, sometimes integrated into the rearview mirror. Some use laser sensors mounted on the front of the vehicle or infrared sensors mounted behind the windshield or under the car. The computer in the car is really quite powerful. It’s called a Hough transform and Canny edge detector. The computer system detects lane changes from real time camera images from the front of the vehicle. The system, camera and computer, is keeping tabs on that white, broken white, or yellow line.

Steering inputs and camera images are fed into the computer system to change the steering angle to keep the car in its proper lane. The system is turned off on the side that has an operating turn signal.

Really smart people started working on the lane change problem back in the early 2000s. They recognized that many accidents occurred due to driver errors, distractions, and drowsiness. The first patent was issued to Englishman Nick Parish in 1989 and fitted on a Rover SD1.