Guide to Lane Departure Warning & Lane Keeping Assist
Explaining how these systems can keep drivers on the right track
Lane keeping and lane departure systems use forward-facing cameras to monitor the lane lines around your vehicle and will provide visual, audible, and/or tactile warnings—such as through steering wheel or seat vibrations—to alert the driver when the car approaches or crosses lane markings. These systems do not activate when you use your turn signal. If your vehicle has lane keeping assist (LKA), automatic steering or braking will try to correct the vehicle if it starts to exit the lane.
There are several common variations of lane systems:
Lane Departure Warning (LDW): Drivers get audible and/or visual warnings that their vehicle is approaching or crossing lane markings when the turn signal is not activated.
Lane Keeping Assist (LKA): Provides automatic steering and/or braking to keep a vehicle in its travel lane.
Road Departure Assist: Provides automatic steering and/or braking to try to keep the vehicle from departing the roadway.
Lane Centering Assist (LCA): Provides automatic steering and/or braking to continually center the vehicle in its lane.
In a recent survey, we asked CR members to rate their experiences with the advanced safety and driver-assist systems on their model-year 2015-2019 cars. Respondents answered questions about their satisfaction with the systems and told us which ones helped them avoid a crash. The survey covered about 72,000 vehicles. See the highlights below.
Which Brands Do LDW and LKA Best?
Most satisfying lane departure warning systems, according to CR members: Hyundai, Cadillac, Buick, Jeep
One Jeep Grand Cherokee owner said, “Visual and sound are completely reliable and immediately activated when the slightest lane departure is detected. This is a very reassuring feature and I rely heavily on it for safety.”
Despite Hyundai topping the LDW rankings, these systems can have drawbacks. One owner points out, “Sometimes cracks in the pavement (or old lane lines that have been painted over) set it off even if I'm in the lane, so that could be improved.” Another Hyundai owner wrote, “I like it but can be irritating where there are uneven lanes, merge lanes or construction lane shifts.”
Least satisfying lane departure warning systems: Infiniti, Porsche, Honda
Infiniti owners were mixed on LDW, with some appreciating the assistance and many finding it frustrating: “It is annoying to hear a beeping noise every time I get close to or on the line.”
Most satisfying lane keeping assist systems: Genesis, Tesla, Kia, Cadillac
Many Genesis owners loved their LKA system: “Allows me to drive longer distances in a day, more relaxed, making long driving less demanding on me and therefore arriving less tired,” one said.
A Cadillac owner wrote, “It is a good system. If I try to change lanes without giving a turn signal, it brings me back. Makes me more conscious of using my turn signal.”
Least satisfying lane keeping assist: Audi, Honda, Lincoln, Acura
Many Audi owners had high expectations for their system. One A8 owner wrote, “It works only intermittently, even when the lane markings are perfect.” An A6 driver added, “More of a nuisance under normal conditions. If I thought I may be drowsy, I might engage it—otherwise I keep it disengaged.”
A Honda CR-V owner wrote, “It's very unreliable. A lot of times it refuses to detect the highway lanes especially at night time and even in rainy weather. It's also unpredictable with some moderate turns on the highway.” A Honda Odyssey driver added, “I have found the lane assist feature troublesome. It detects lane departures when there are none and gets confused by some line markings.”
CR’s Take: LDW systems can help sleepy or distracted drivers stay safe. The alerts also provide a good reminder to use your turn signal when changing lanes. But systems that are too sensitive and have lots of annoying false positives, particularly audible alerts, can cause drivers to turn them off, negating their benefits. When using LKA, giving a wide berth to a cyclist or pedestrian might cause the system to try to steer back toward the cyclist or walker, so always be alert. Most systems require drivers to keep their hands on the wheel. But lightly holding the steering wheel—to prevent the system from issuing an alert—doesn’t mean the driver is paying attention to the road.
Brand Names for Lane Systems
|Acura||Lane departure warning and lane keeping assist|
|Alfa Romeo||Lane departure warning|
|Audi||Lane departure warning/Audi active lane assist|
|BMW||Lane departure warning|
|BMW||Active lane keeping assistant with side collision avoidance|
|Buick||Lane keep assist with lane departure warning|
|Buick||Lane departure warning|
|Cadillac||Lane keep assist with lane departure warning|
|Chevrolet||Lane keep assist with lane departure warning|
|Chrysler||Lane departure warning with lane keep assist/LaneSense|
|Fiat||Lane departure warning with lane keep assist/LaneSense|
|Ford||Lane keeping system|
|Genesis||Lane departure warning and lane keeping assist|
|GMC||Lane keep assist w/lane departure warning|
|Honda||Lane departure warning|
|Honda||Lane keeping assist system|
|Hyundai||Lane departure warning and lane keep assist|
|Infiniti||Lane departure prevention|
|Kia||Lane keep assist|
|Kia||Lane departure warning|
|Lexus||Lane departure warning|
|Lexus||Lane departure alert with steering assist|
|Lincoln||Lane keeping system|
|Mazda||Lane keep assist system and lane departure warning|
|Mercedes-Benz||Active lane keeping assist|
|Mitsubishi||Lane departure warning|
|Nissan||Lane departure warning and lane departure prevention|
|Nissan||Intelligent lane intervention|
|Porsche||Lane keeping assist|
|Subaru||Lane departure warning and lane keeping assist/EyeSight System|
|Toyota||Lane departure alert|
|Toyota||Lane departure alert with steering assist function|
|Toyota||Lane tracing assist|
|Volvo||Oncoming lane mitigation|
|Volvo||Lane keeping aid|