Adaptive cruise almost caused an accident

[Blue Sky]

Don't change the title!

It's getting views. Hopefully, this can educate some folks on more appropriate adaptive cruise control usage scenarios.

I agree with Alpha Puppy, people need to ease up. And no, I do not advocate for using adaptive cruise in this manner (or really at all, I have almost not trust in any self driving tech at this point, call me a luddite, it's cool I can take the heat). But I think point has been made; brow beating the OP into oblivion doesn't serve any other purpose than an ego trip. I respect the hell out of what a lot of you have to say regarding our Landcruisers but people, be cool.

Take a look at my forum photo, I dunked my '58 in 3 or 4 river crossings with the odometer at 156 miles on it. And you know what? Now I get to drain and refill my rear differential because I didn't realize the breather can take in water if submerged without an adapter kit. And then there is the debate about break-in periods. Point is, I made and make mistakes. I am on this forum to learn about our LCs and be more informed.

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[PDPete]

And no, I do not advocate for using adaptive cruise in this manner (or really at all, I have almost not trust in any self driving tech at this point, call me a luddite, it's cool I can take the heat)

So let's turn the clock back a bit to days before radar-assisted adaptive cruise control (ACC)...

when driving with old school cruise control (CC), you set a speed, and the vehicle will maintain that speed until one of three things happen: the driver cancels CC, the driver applies the brakes, or the vehicle collides with something and wrecks. Standard CC was very convenient for maintaining speed on longer stretches of highway with light, infrequent traffic, but you had to always be vigilant as you come on other vehicles to avoid accidents as your vehicle would attempt to just plow right through them if CC was left on...it was often a pattern of "set CC, cancel CC to slow down when coming upon heavier traffic, pass slower traffic, resume CC once clear".

Having ACC makes this entire process much easier...you now shouldn't have to worry about plowing into the rear end of a vehicle traveling slower than you are, as the vehicle should detect it and adjust its speed accordingly...this is a great feature, but it doesn't mean that the driver can just take a nap and trust the vehicle to drive for them. After having ACC on both this new Land Cruiser and my previous vehicle, I've come to trust it to do a "pretty good" job of what it's designed to do...but I'm always ready to apply the brakes if necessary, and generally will manually cancel ACC (via the brakes or using the steering wheel button) if it has had to significantly decelerate below my set speed at any time, because at that point I no longer feel that I'm in ideal CC or ACC driving conditions and want full control over my vehicle, regardless if it's for slowing down even more, or getting back up to speed once I have a clear lane in front of me again.

In other words, I don't think one needs to be a complete "luddite" about it, but erring on the side of caution is never a bad thing either.

In OP's case, that's one where I definitely would have already taken over manual control of the vehicle...clearly the ACC system was responding properly to the truck/trailer in front of him, but when it moved out of the path of the LC, the default behavior of resuming ACC set speed kicked in before the next vehicle ahead could be accurately detected by the system. Fortunately OP did react in time, and hopefully now has a healthier respect for the limitations of the technology.

 

[LC510]

User error

 

[HarvLC]

Frankly, I haven’t warmed up to the idea of ACC as being overly beneficial. I never found the non-adaptive version to be overly risky nor labor intensive.

If anything, ACC too often lulls me into situations where I end up lingering at 68mph in the right lane behind a slow vehicle with my setting at 77mph - ie, I didn’t notice the vehicle gradually slowing as I approached that vehicle and didn’t timely move over to the left lane for a smoother pass.

 

[Marinna]

From social media point of view, complaining about ADAS failure will rarely give you any positive recognition unless you can help to systematically analyze it with sufficient coverage to all scenarios to make your report useful to other drivers.

The road with traffic light isn’t really a “highway” as it can’t enforce a minimal speed limit. The ACC feature is supposedly only used on highway when a completely stop is a rare scene, and even Tesla you can’t trust this basic feature completely as it has been documented to fail in multiple situations.

I am not sure what is the distance you set for ACC, if it’s the shortest it is not absolutely not adequate to handle this from my experience. .

Just think about this. If you do run into an accident following ACC’s recommendation, not only you will be fully responsible, but also Toyota and judge will very unlikely to accept your argument that ACC should to liable at all in this situation, should you choose to file any legal complaint. That should give you a perspective how to treat ADAS on your vehicle.

 

[EOD Guy]

Some of ya'll crack me up!

 

[Altitude]

The situation you described is one of the most dangerous things we face as drivers. You’re following a vehicle at speed, there is a stopped vehicle or object in front of the vehicle you’re following. The vehicle in front of you does not slow down, but bails into another lane to avoid hitting the stopped car and you have no idea there’s anything there at all until the very last second.

I’m not surprised the self driving system struggled with that.

Another situation I’ve experienced where its handling was less than elegant was when a driver moves into my lane, inside of the follow zone, and traveling slower than I am. The truck freaks out a bit when that happens. Actually sort of the opposite of the OP’s situation but another scenario where I think manual intervention is necessary.

 

[thognar]

Some great observations in this thread. I've found that ACC works well on larger highways (no stop lights/signs, traffic flow is not changing radically, grade isn't changing radically, lines on both right and left sides are well defined, etc) but not in other situations. ACC is a handy feature for those 'easy' roads but otherwise I do the driving.

 

[TheBat]

When I'm following another vehicle and they come to a normal stop I'll let ACC handle it, but if I'm approaching a stopped vehicle I find that it does not detect the situation soon enough. Basically if under my control I'd be coasting (or even braking) and ACC is still holding speed, I hit cancel and take over. Even if ACC might be able to stop safely I don't like it coming in hot to a stopped vehicle so I take over.

 

[ultane]

When I'm following another vehicle and they come to a normal stop I'll let ACC handle it, but if I'm approaching a stopped vehicle I find that it does not detect the situation soon enough. Basically when under my control if I'd be coasting (or even braking) and ACC is still holding speed, I hit the cancel and take over. Even if ACC might be able to stop safely I don't like it coming in hot to a stopped vehicle so I take over.

Ditto..

 

[Bigfoot]

Was following a pickup towing a landscaping trailer. On a rural 4 lane highway, with a grass median. I was in the right lane, behind the pickup. Original speed was 58, and there was a red traffic light ahead. The truck started slowing down, as did I. There was a small Hyundai stopped at the intersection in front of the truck. The left lane was open beside the Hyundai, and the truck abruptly swerved into the left lane. The speed was approximately 40 MPH when the truck changed lanes. With the stopped Hyundai directly in front of me, the adaptive cruise did not continue to brake. It apparently didn’t detect the Hyundai at all, so I got on the brakes as hard as I could. Stopped with a foot and change to spare, but if I hadn’t hit the brakes hard, I’m pretty convinced I would have plowed into the stopped car. I’ve got the following distance set to the maximum, and it still comes in a little hot for my tastes with stopped traffic ahead. So just when my confidence in adaptive cruise was getting pretty good, this happened. Bottom line, you better have decent reflexes because you don’t get much warning when things don’t go right.

The system can adapt to many but not all situations. The Owner's Manual notes that you must be vigilant for unexpected conditions where the system may not work including when the preceding vehicle suddenly changes lanes, slow moving or stopped vehicles, motorcycles, etc. IOW don't expect too much of the system.

 

[cburkhart]

Was following a pickup towing a landscaping trailer. On a rural 4 lane highway, with a grass median. I was in the right lane, behind the pickup. Original speed was 58, and there was a red traffic light ahead. The truck started slowing down, as did I. There was a small Hyundai stopped at the intersection in front of the truck. The left lane was open beside the Hyundai, and the truck abruptly swerved into the left lane. The speed was approximately 40 MPH when the truck changed lanes. With the stopped Hyundai directly in front of me, the adaptive cruise did not continue to brake. It apparently didn’t detect the Hyundai at all, so I got on the brakes as hard as I could. Stopped with a foot and change to spare, but if I hadn’t hit the brakes hard, I’m pretty convinced I would have plowed into the stopped car. I’ve got the following distance set to the maximum, and it still comes in a little hot for my tastes with stopped traffic ahead. So just when my confidence in adaptive cruise was getting pretty good, this happened. Bottom line, you better have decent reflexes because you don’t get much warning when things don’t go right.

So is it possible to disable the adaptive cruise control? If so, how is that done?

 

[ultane]

So is it possible to disable the adaptive cruise control? If so, how is that done?

There is a lot of information on the use of it, it the owners manual..

 

[ChillLC]

This thread is great... sharing opinions is not bullying. I'm in the camp that believes adaptive cc is NOT self-driving and this thread helps reinforce my decision to only use this feature on long freeway trips.... (with no stop lights). Personally, I enjoy driving and feel safest when I control the vehicle. (knocking on wood) 50+ years without an accident!

 

[GrayBeard]

So let's turn the clock back a bit to days before radar-assisted adaptive cruise control (ACC)...

when driving with old school cruise control (CC), you set a speed, and the vehicle will maintain that speed until one of three things happen: the driver cancels CC, the driver applies the brakes, or the vehicle collides with something and wrecks. Standard CC was very convenient for maintaining speed on longer stretches of highway with light, infrequent traffic, but you had to always be vigilant as you come on other vehicles to avoid accidents as your vehicle would attempt to just plow right through them if CC was left on...it was often a pattern of "set CC, cancel CC to slow down when coming upon heavier traffic, pass slower traffic, resume CC once clear".

Having ACC makes this entire process much easier...you now shouldn't have to worry about plowing into the rear end of a vehicle traveling slower than you are, as the vehicle should detect it and adjust its speed accordingly...this is a great feature, but it doesn't mean that the driver can just take a nap and trust the vehicle to drive for them. After having ACC on both this new Land Cruiser and my previous vehicle, I've come to trust it to do a "pretty good" job of what it's designed to do...but I'm always ready to apply the brakes if necessary, and generally will manually cancel ACC (via the brakes or using the steering wheel button) if it has had to significantly decelerate below my set speed at any time, because at that point I no longer feel that I'm in ideal CC or ACC driving conditions and want full control over my vehicle, regardless if it's for slowing down even more, or getting back up to speed once I have a clear lane in front of me again.

In other words, I don't think one needs to be a complete "luddite" about it, but erring on the side of caution is never a bad thing either.

In OP's case, that's one where I definitely would have already taken over manual control of the vehicle...clearly the ACC system was responding properly to the truck/trailer in front of him, but when it moved out of the path of the LC, the default behavior of resuming ACC set speed kicked in before the next vehicle ahead could be accurately detected by the system. Fortunately OP did react in time, and hopefully now has a healthier respect for the limitations of the technology.

When I'm following another vehicle and they come to a normal stop I'll let ACC handle it, but if I'm approaching a stopped vehicle I find that it does not detect the situation soon enough. Basically if under my control I'd be coasting (or even braking) and ACC is still holding speed, I hit cancel and take over. Even if ACC might be able to stop safely I don't like it coming in hot to a stopped vehicle so I take over.

I agree with these. Adaptive cruise control is great for the few times I want to use cruise control, because if someone is in front of me doing a couple of miles an hour slower I don't have to reset everything. But I still treat the radar and braking function as assistance, not self-driving. That being said, I'm only using it as much as I am right now because I want to know the limitations of the system.

I am finding that TJA is useful. I was stuck behind a fairly major jam last week and what would have been an infuriating 20 minutes in stop and go traffic was only mildly annoying, though I still had to look out for people shifting lanes. But that brings up something I observed relating to:

From social media point of view, complaining about ADAS failure will rarely give you any positive recognition unless you can help to systematically analyze it with sufficient coverage to all scenarios to make your report useful to other drivers.

The road with traffic light isn’t really a “highway” as it can’t enforce a minimal speed limit. The ACC feature is supposedly only used on highway when a completely stop is a rare scene, and even Tesla you can’t trust this basic feature completely as it has been documented to fail in multiple situations.

I am not sure what is the distance you set for ACC, if it’s the shortest it is not absolutely not adequate to handle this from my experience. .

Just think about this. If you do run into an accident following ACC’s recommendation, not only you will be fully responsible, but also Toyota and judge will very unlikely to accept your argument that ACC should to liable at all in this situation, should you choose to file any legal complaint. That should give you a perspective how to treat ADAS on your vehicle.

When trying Adaptive cruise I've settled on two "bars" of following distance in general. Depending on the road and traffic sometimes three. But in TJA I set it to the full four and found out that it made for an extremely uncomfortable ride as the LC would wait until a significant distance opened up and then accelerate (harder than I would have liked) only to then jump on the brakes (me or the LC depending on my comfort level). Counter-intuitively, when set to the shortest "one bar" the LC followed much more gently and evenly behind the car in front.

That held true up to about 15-18 mph, at which point traffic was getting too chaotic for me to be comfortable with the computer and I just went manual.

Another lesson learned: I'd forgotten I'd set the following distance to one bar and was doing more adaptive cc for practice / familiarity. Normally there's a nice reminder there in the HUD of what distance you've set. But I was close to my next turn and using Nav in the HUD (on the "normal" HUD setting). In that case the turn point displaces the driver assist iconography and I found myself coming up behind the car in front of me far faster than I would have liked and took over braking myself. That's on me, just sharing knowledge. I haven't tried it with the "full" HUD setting.

 

[alain.mlmn]

Was following a pickup towing a landscaping trailer. On a rural 4 lane highway, with a grass median. I was in the right lane, behind the pickup. Original speed was 58, and there was a red traffic light ahead. The truck started slowing down, as did I. There was a small Hyundai stopped at the intersection in front of the truck. The left lane was open beside the Hyundai, and the truck abruptly swerved into the left lane. The speed was approximately 40 MPH when the truck changed lanes. With the stopped Hyundai directly in front of me, the adaptive cruise did not continue to brake. It apparently didn’t detect the Hyundai at all, so I got on the brakes as hard as I could. Stopped with a foot and change to spare, but if I hadn’t hit the brakes hard, I’m pretty convinced I would have plowed into the stopped car. I’ve got the following distance set to the maximum, and it still comes in a little hot for my tastes with stopped traffic ahead. So just when my confidence in adaptive cruise was getting pretty good, this happened. Bottom line, you better have decent reflexes because you don’t get much warning when things don’t go right.

Thank you for your post. It is a good warning . I love the Adaptive Cruise Control but you made me aware to be aware. Good reaction too. I think the ACC "thought" you would follow the truck, maybe. Never the less, I now will treat the ACC as not tailless. Tnx again.

 

[kruising]

Love ACC w/steering - it makes trips much less tiring, especially in stop and go traffic. But it does seem to be more reliable when following a car that is doing the appropriate thing. I would have expected the truck to pick up speed once the one you were following moved over so maybe the ACC had already been cancelled somehow, though there is sometimes a bit of a delay before speed picks up in those situations. Maybe that's why it seemed nothing changed right at first. Thanks for sharing this incident for our awareness.