2017~2024 Lane Keep and Lane Departure - Wild Inconsistencies

[181962]

2020 CX-5 Touring AWD - Set to Sensitivity-High, Vibration-High / Audible Off

In normal driving without testing I noticed in early ownership I was getting consistent vibration on shoulder white line detection but nothing on yellow line detection except once. So I just went out and tested this on two-lane black tops.

One road was freshly paved and then striped just last week. I did a variety of tests crossing a variety of center yellow lines: double solid yellow, solid with broken yellow, and single broken yellow. Turning the corner I tested badly faded broken yellow. I kept the speed consistent around 50-55 mph. Of course I kept the turn signal off when crossing these lines.

The roads were perfectly dry, skies clear and sunny but not blinding. It was 5:00 PM, the sun getting lower in the sky, lots of trees lining these roads, so no harsh sun. In short, ideal driving conditions. The car is quite clean except for spotting on the rear window and bumper from a recent drive through rain.

There was no rhyme or reason to the system's behavior. Sometimes it did nothing. Sometimes I'd get the expected vibration but no detectable feeling of lane correction. Sometimes holding the wheel very lightly there would be no vibration but it would ease back into my lane. I could get one result with one particular line combination, drive a couple hundred feet, try again over the same line combination and get a different result.

Driving away from home the system seemed to activate one way or another less frequently than on the return trip.

Anybody else have a similar experience or an explantion?

 

[181962]

I found the answers to those perplexing tests in the OP. The diagram in the manual on the first page of the section covering these systems (2020, page 4-162) is misleading. The cautions on the following page led me to the answers.

With the turn signal off, If the driver makes an "abrupt" move close to a road line the Lane-Keep/Departure systems will be suspended. That's according to the manual. "Abrupt" is an interesting choice of term. The correct way to look at is a "more than subtle" line approch will suspend the system.

If you did what is shown in the diagram at 50 mph, that would be "abrupt" and the system will suspend. Even a less angled lane departure at that speed would be "abrupt". That was why some of my tests in the OP had inconsistent results. I was being "abrupt" at times and not others.

Further, the manual says the systems may be suspended if the vehicle departs from it's lane repeatedly over a short period of time. I don't know how that is quantified but it would seem to account for some of my other odd test results. That said, if you're drunk and weaving down the road chances are the systems will suspend, if that matters to anybody.

Something I had noticed but wanted to test further was a lone exception or maybe two to white shoulder line recogntion. The answer according to the manual is that the system may not operate on roads with tight turns. "Tight" is another interesting choice of term. Lets say a "more than subtle curve."

After reading this stuff and repeating my tests again in ideal driving conditions, all is well in Edgeland. Like the door locks, these systems don't behave as the manual led me to believe, but I'm pretty darn happy with how they actually work now that I've figured them out.

There are a bunch more conditions where these systems may suspend that I did not test. That's worth a read.

 

[rockethead26]

I noticed inconsistencies as well, but after reading your thread, I tested on the way to work this morning. As you noted all gradual approaches to white or yellow lines caused a warning whereas a more sudden move did not. Thanks for solving this one, it was driving me nuts.

 

[sm1ke]

Sounds like it's just a matter of interpretation and managing expectations.

 

[181962]

Sounds like it's just a matter of interpretation and managing expectations.

Not really. Words and pictures have meanings. Supposed to anyway. You're right about expectations, though. The manual managed me right into false ones. I've said it before and I'll say it again--great car, terrible manual.

 

[ruthrj]

I didn’t find how the system responds super intuitive when I drove the 2017. My ‘19 RAV4’s system seems much more natural. It beeps if you depart the lane without using the turn signal. Have to turn it off with a button on the steering wheel if that’s too annoying.

 

[181962]

I didn’t find how the system responds super intuitive when I drove the 2017. My ‘19 RAV4’s system seems much more natural. It beeps if you depart the lane without using the turn signal. Have to turn it off with a button on the steering wheel if that’s too annoying.

I like how the 2020 CX-5 functions now that I understand it, no thanks to the manual's red herrings. It only engages if the lane depature is subtle which might not be everybody's preference but it suits me just fine. I'm set for steering wheel vibrations only; the beeps would drive me nuts. The only beeping I want to hear is from the blind spot detector.

 

[sm1ke]

Not really. Words and pictures have meanings. Supposed to anyway. You're right about expectations, though. The manual managed me right into false ones. I've said it before and I'll say it again--great car, terrible manual.

We'll agree to disagree. I think your interpretations of the words, combined with the expectations you may have developed from your previous cars, makes it seem like the manual is wrong, or at the very least, poorly written. I'll agree that the manual can be improved in a lot of ways (speaking as a consumer and as a tech writer).

"With the turn signal off, If the driver makes an "abrupt" move close to a road line the Lane-Keep/Departure systems will be suspended."

When I read this, I interpret "abrupt" as intentional. I don't think anyone would abruptly cross the lane markings without intending to do so (swerving to avoid a pedestrian, for example). Thus if the system recognizes the abrupt input as intentional, there is no reason to warn the driver.

"Further, the manual says the systems may be suspended if the vehicle departs from it's lane repeatedly over a short period of time."

Same thing here. If the vehicle departs from its lane repeatedly, the system may interpret that behaviour as intentional. It doesn't assess the fact that you might be drunk, lol.

If anything, this is a pretty clear reminder to me that all of these systems from any manufacturer are driving aids, not substitutes for driving.

 

[181962]

...expectations you may have developed from your previous cars, makes it seem like the manual is wrong, or at the very least, poorly written...

I had zero expectations from previous cars because none had any of these safety features. Not even keyless ignition or radar cruise for that matter. I developed some expectations from the manual then put them to the test on the road.

"With the turn signal off, If the driver makes an "abrupt" move close to a road line the Lane-Keep/Departure systems will be suspended." When I read this, I interpret "abrupt" as intentional.

First, the vehicle has no idea of human intentions, nor should it try. Second, "abrupt" is decidely not the criterion. The criterion is "more than subtle" as I said. A more than subtle lane departure could certainly be non-intentional. Intentionality is clearly not the critera. Third, as noted previously, if you look at the diagram in the manual of how it works, showing the car steering back in it's lane, the reality is if you did that on the road at that attack angle at 50 mph as I tested it, it would be treated as "abrupt" and the system would suspend.

If the vehicle departs from its lane repeatedly, the system may interpret that behaviour as intentional. It doesn't assess the fact that you might be drunk, lol.

Agreed. My comment about the drunks was a throwaway line "in case anybody cares about that". But since you mention it, I would say a drunk weaving all over the road is not doing so intentionally which runs counter to your characterization. I will say that's the one and only passage in the manual that explicity resolves some of my original test issues.

If anything, this is a pretty clear reminder to me that all of these systems from any manufacturer are driving aids, not substitutes for driving.

That was never my point. At all. That these systems are backstops in the event of some mistakes, certainly not all or even most, is not in question. As stated elsewhere, any characterization of any vehicle on the road as "sel-driving" or "autonomous". Maybe if Elon Musk spent a night in jail every time he used the "a" word he'd quit using that term and his customers wouldn't be driving down the road reading or playing with their phone or watching a movie or napping.

That they are merely backstops is the one expectation I had coming in which I've commented on several times here and elsewhere. My point is that before trying to figure out how these systems actually work on the road at 50 mph it's just might be a good idea to develop some expectations from the manual. In this case, the manual is misleading.

Like I said before, more than once I think in this thread, I have no problem with how the vehicle functions. It operates conservatively to sharply limit false positives as it were. That is as it should be. My beef is with this 2020 manual . I don't think there's much point in trying to defend the clarity and accuracy of many of those 1,000 pages.

 

[sm1ke]

I had zero expectations from previous cars because none had any of these safety features. Not even keyless ignition or radar cruise for that matter. I developed some expectations from the manual then put them to the test on the road.

First, the vehicle has no idea of human intentions, nor should it try. Second, "abrupt" is decidely not the criterion. The criterion is "more than subtle" as I said. A more than subtle lane departure could certainly be non-intentional. Intentionality is clearly not the critera. Third, as noted previously, if you look at the diagram in the manual of how it works, showing the car steering back in it's lane, the reality is if you did that on the road at that attack angle at 50 mph as I tested it, it would be treated as "abrupt" and the system would suspend.

Agreed. My comment about the drunks was a throwaway line "in case anybody cares about that". But since you mention it, I would say a drunk weaving all over the road is not doing so intentionally which runs counter to your characterization. I will say that's the one and only passage in the manual that explicity resolves some of my original test issues.

That was never my point. At all. That these systems are backstops in the event of some mistakes, certainly not all or even most, is not in question. As stated elsewhere, any characterization of any vehicle on the road as "sel-driving" or "autonomous". Maybe if Elon Musk spent a night in jail every time he used the "a" word he'd quit using that term and his customers wouldn't be driving down the road reading or playing with their phone or watching a movie or napping.

That they are merely backstops is the one expectation I had coming in which I've commented on several times here and elsewhere. My point is that before trying to figure out how these systems actually work on the road at 50 mph it's just might be a good idea to develop some expectations from the manual. In this case, the manual is misleading.

Like I said before, more than once I think in this thread, I have no problem with how the vehicle functions. It operates conservatively to sharply limit false positives as it were. That is as it should be. My beef is with this 2020 manual . I don't think there's much point in trying to defend the clarity and accuracy of many of those 1,000 pages.

As I said, agree to disagree. The manual's explanation doesn't work for you, but it works just fine for me.

 

[181962]

As I said, agree to disagree. The manual's explanation doesn't work for you, but it works just fine for me.

If you agree to disagree then you should stop disagreeing.

 

[sm1ke]

I you agree to disagree then you should stop disagreeing.

Agreeing to disagree means that I respect your opinion, I just don't agree with it, and I'm willing to leave it at that.

 

[Davidiot]

I’m a guy who frequently changes lanes without signaling — I tend to only use turn signals when I feel they will be useful to other drivers. I don’t signal lane changes on empty highways, for example.

My car (2020 GT+PP) seems to have learned this about me and quickly stopped trying to correct me by fighting me for control of the steering wheel. I appreciate this.

If I’m getting tired, or distracted by a phone call, and thus electing to just stay in one lane, I think the car then decides it’s okay to provide an assist. I also find it humorous that the car instructs you to hold the wheel if you loosen your grip while testing this function; and even more so that it apparently will suggest you pull over for coffee if it detects you’ve started reacting more slowly than normal ... though this warning I have never actually experienced.

 

[hal2]

Since when does abrupt mean intentional? Abrupt to me is obvious that it means not subtle, acute sharp lane change, as opposed to gentle drifting.. Maybe only the Signature gets a version of everything working well. My BSM, Lane Departure warnings, lane correction, everything seem to work well