I have a 2018 E63S Wagon. Love it. But there is one feature which I have learned to hate and want to see if anyone knows how to get around it.

My vehicle has a feature (not sure if it's standard) where if the car detects you veering across a solid line (had this experience with white and yellow lines, and on both sides of the vehicle) it will tap the brakes and jolt the steering back towards the main lane. On the face of it this seems like a sensible feature, but it is kicking in fairly regularly now and every time it does it catches me by surprise and gets my heart racing more than it should be.

The first scenario I have seen that really catches me are relatively sharp left hand curves on medium speed roads. There is a road called Anderson Mill in Austin which is a suburban street, 40 mph with almost a full shoulder separated by a solid line. There is a left curve which constantly causes the system to trigger when I am driving in the right lane, next to the shoulder.

The more annoying scenario will be a situation where for example we have 2 lanes in each direction separated by a solid line in an urban environment. If I am in the left lane I will often position myself right up against the center line particularly when I can see there is no oncoming traffic, and where there is maybe some risk of people entering and exiting from the right lane. Several times the car thinks I am drifting over the solid line and will push me back towards the right lane.

I've done some digging through menus but haven't seen anything that might help with this. Anybody know how to turn this feature off? I wasn't sure if it was possible given this probably falls into the category of safety features, vs autonomous driving tech.

 

There's a panel of buttons to the left of the steering wheel. There's a button there to turn off active lane assist.

 

I thought the active lane assist was the monitor to keep you centered in the lane. I have turned that off (will double check the wife didn't turn it back on) but I found that to be just a bit annoying where the car would fight you if you tried to change lanes without indicating.

The response I am describing is much more aggressive. There is an alarm sound, a noticeable braking effect and a graphic that pops up in the HUD with a big red line next to a white line.

Will have a look and make sure the active lane assist is turned off and see if that helps. Thanks for the suggestion.

 

It’s the same button. I’ve had it turned off in my wife’s GLS since two days after we bought it because of the same issue you described. We don’t have a button, I turned it off in the MBUX menu.

 

Thanks for the feedback. Confirmed there were 2 buttons on in the left panel. The steering wheel one and the one that looks like a lane. Turned them both off.

Feel like an idiot for not checking that sooner. Just never look at that panel in general use. Hopefully will be able to have my morning commute without the panicky adrenaline rush now.

Thanks everyone.

 

If I'm not mistaken, the one with the steering wheel on it engages the lane keeping assist when you activate the cruise control. If that button is turned off, you'll have the cruise control function only and not the self driving feature that keeps the car in the lane.

I generally have the self driving lane keeping assist during cruise control turned on, but the lane departure warning annoyance feature turned off.

So if I drift over a line without cruise control turned on I don't get the steering wheel grab and brake action. Like everyone else I found that very annoying.

The only time I turn it back on is if I start getting drowsy or having trouble staying focused at the end of a long drive.

 

The sudden wheel grab and brake is alarming, to say the least. I'm surprised how aggressive it is.

 

The one with the steering wheel is the Active Steering Assist. It actually steers the car in its lane and is only active together with DISTRONIC. The one with the lane markers is the lane keeping assist which violently yanks you back into your lane using corrective braking actions and also vibrates the steering wheel. I have the lane keeping assist turned off. Don't really need assistance to stay in my lane, but I use the Active Steering Assist in traffic and long highway cruising, so I have that turned on. During normal driving it doesn't do anything, only when DISTRONIC is engaged.

 

Thanks for all the feedback folks. Totally hadn't figured out the different roles of those buttons/systems.

It's slightly disappointing as I'm generally a fan of these types of automated safety systems, but this is just a bad implementation in my book. The response doesn't match the action. If I were veering into a barrier the reaction would be fine, but not for crossing a line.

I also think it shows the challenge we are going to have in getting to full autonomous driving. These systems need more contextual understanding and a wider range of responses, and that is gonna take a bunch of effort to figure out.

Anyway, thanks for the help. On the one hand I feel like an idiot for having to ask, and on the other I feel like an idiot for not asking sooner and getting it solved.

 

Car is taking corrective action to prevent possible accident because it appears as drifting out of the lane.

There is a simple fix for those annoyed by car’s intervention:

Use turn signal before crossing the line —> the lane assist will not react since all is under control…

 

Mercedes actually does a lot of research on the effectiveness of their safety systems. For example they were the first to determine that the blind spot warning should be in the mirror itself and not the housing as more people noticed it when it was in the mirrors. They are also one of the few or still the only one that also have an acoustic warning for the blind spot system. I like how they separated the lane keep function from the active steering function. The latter being purely a convenience and assistance system, and the former just a safety system. Many other makes roll them together and then they are neither here nor there.

The major difference between the two is that the latter does factor in contextual information and actively steers the car. It uses all the available sensors and cameras to detect other cars, lane markings and even walls around the car and uses them to follow the current lane. It can actually continue to follow other cars ahead if there are temporarily no lane markers. It's also aware by means of the navigation map what type of road you are currently driving on and behaves differently on a divided highway vs a surface road. Same for DISTRONIC. For example the extended restart function, resumes driving for up to 30 seconds after traffic comes to a stop if you are driving on a divided highway, whereas on surface streets it's much more conservative.

Lane keeping on the other hand is purely a safety system. It just uses the front cameras to recognize the lane markers and then warns you first via audible, visual and tactile warnings before it applies the brakes to make a correction. Using the brakes seems harsh, but it does serve as a wakeup call for the driver if they are slowly drifting out of the lane while dosing off for example. So there is purpose behind it. In AMGs it's also tuned to recognize a dynamic driving style. When driving in a spirited manner it lets you cross the lanes w/o intervening. I used to have it on and when I went for a drive in the canyons it would never intervene if I crossed over the center lane for example, so it's tuned fairly well, but it became mostly annoying in normal driving. The vibration in the steering wheel actually annoyed me the most when it mistook cracks in the road as lane markers or when two lanes merged then it vibrated if I crossed over the ending lane marker. I pretty much only turn it on now if I feel I'm getting a little groggy on a long drive. That's really what it's for. And yes as just said above, use the turn signals when changing lanes.

 

Yeah, that's not what I'm talking about. I am fine with the lane keeping assist that makes small corrections to maintain the lane discipline. That is a scenario where using the indicator will stop the behavior.

What I am referring to is the car taking an aggressive action (visual/audible alarms, turning correction and braking) to a relatively innocuous situation where the car may cross a line at a very shallow angle where I am not attempting to make a lane change, but may be positioning the vehicle in the most appropriate manner based on everything I can see happening around me. I have also not experienced progressive warnings when it comes to crossing of a solid line. It feels like a 0-100 implementation to me.

But again some context. My background is in industrial control systems engineering. These automated driving systems are fascinating and I love the technology. But in this very specific scenario, I don't think this is well implemented and so will be keeping the function off, save for the scenario described above where perhaps I am aware I'm not at 100% personally.

Feel free to come to your own conclusions, as I suspect the technology may perform better in some environments than others, given the wide variety of roadway conditions these cars are planned to encounter across the world. But where I live with huge wide roads with white lines far from the edge of the road way, this system can be annoying.

To close I will share one other example that happened to me a few days ago (prior to this post). The 610 in Houston is undergoing major construction. The construction requires lanes to be rerouted which is typically done with temporary markers rather than painting new lines. Sometimes the workers are not the most diligent at removing the pre-existing lines. So I was driving in the right most lane on a 5/6 lane freeway, and as we approach the construction area my lane gets re-routed to use about half of the width of the shoulder. As I'm drifting across the white line (following the new temporary markers for my lane), boom, lights, noise, brakes and steering correction, all leading to a raised heart-beat and a few unnecessary expletives. Again, no progressive warnings, just an overly reactive safety system which in my opinion will remain turned off unless I feel I need it's support.

 

Yes, I think we are on the same page. The lane keep assist is fairly dumb in all cars, because it only factors in lane markers. Your last example is a good one, that is difficult to handle. I actually did European Delivery with mine, and the rerouted lanes worked great in places like Germany. They use a very distinct color for the rerouted lane markers and the system recognizes the color and follows the proper lane markers, no longer reacting to the white lines. They are also diligently cleaned up at the end of the construction. These are situations that are difficult to handle by an algorithm, unless the humans doing the construction factor this in. These construction zones effectively have to be mapped out, otherwise it'll be chaos. The new Level 3 Drive Pilot that Mercedes just released in Germany so far simply tells the driver to take over in construction zones. As I've said many times, we are far away from full self driving, despite Elon Musk promising it's just around the corner.

 

I have 21 BMW THAT IS DOING THE SAME: aggressive action if not signaling the lane departure.
Have you tried turning the blinker BEFORE switching the lanes?