Autosteering chooses curve speed like a racedriver, is that expected?

[bumcurriculum]

So I am quite new to the Tesla experience (1 month, 2500km with a 2018 Model S EAP AP2.5), but I can't get my head around how Autosteering selects speed, and how much I can trust or use it.

Is there anywhere a good description of it? The user manual is not very detailed on this topic.

What I see is that the correlation between the recognized speed limit(number in red circle) and the chosen speed(number in blue circle) is totally unclear.

Sometimes I drive in the inner lane of a straight highway with 130km/h, and then out of nowhere the car breaks, blue circle number goes down to 80, red circle number stays 130.

Or at the end of the highway - where it ends in a 270 degree turn on a ramp - there are speed limit signs at the road, like 80, 60, 40 progressing one after the other. According to the number in the red circle the car recognizes the changing speed limits, but it changes the blue circle numbers differently. (at different places and different speeds, without any clear pattern or correlation with the speed limit).
I would say it is choosing the speed like an especially sporty human driver would choose the speed, independent from the speed limit. The stress is on the word "sporty" here, it is quite scary and very stressful to follow the cars decision, and trying to figure out if it will slow down enough to not slip out in the corner, or if I have to take over and brake, and what is the last moment when I can still brake without causing an accident.

Similar happens almost all the time when I am leaving the highway with Autosteering on the ramp. Red circle number stays 130 correctly, car keeps pushing at 130 where I myself would start to gradually slow down to keep things comfortable for the passangers, then just a moment before I would decide to risk no more and take over, it decreases the blue circled number a little bit and starts to slow down, but still going too fast, a bit later decreases the blue number further, slows further down, but still scaringly fast, then I lose the chicken race with the car and start to press the brake, in order to not crash at the turn at the end of the ramp. But still at a very sporty pace.

I don't know if the car would take this turn without human intervention, or just crash itself, I am not brave enough to try.

So basically the car is choosing the speed in turns and ramps like a racedriver(probably would even crash the car if human doesn't intervene, but sometimes in the middle of the straight road it chooses a low speed for seemingly no reason.

The problem with this that I cannot trust the car, which basically makes Autosteering unusable for
me. Or maybe I am just a very slow driver, and Teslas pace is normal?

Is there any way to systematically handle Autosteering, in a sensible way?

 

[Tam]

So I am quite new to the Tesla experience (1 month, 2500km with a 2018 Model S EAP AP2.5), but I can't get my head around how Autosteering selects speed, and how much I can trust or use it.

Is there anywhere a good description of it? The user manual is not very detailed on this topic.

What I see is that the correlation between the recognized speed limit(number in red circle) and the chosen speed(number in blue circle) is totally unclear.

Sometimes I drive in the inner lane of a straight highway with 130km/h, and then out of nowhere the car breaks, blue circle number goes down to 80, red circle number stays 130.

Or at the end of the highway - where it ends in a 270 degree turn on a ramp - there are speed limit signs at the road, like 80, 60, 40 progressing one after the other. According to the number in the red circle the car recognizes the changing speed limits, but it changes the blue circle numbers differently. (at different places and different speeds, without any clear pattern or correlation with the speed limit).
I would say it is choosing the speed like an especially sporty human driver would choose the speed, independent from the speed limit. The stress is on the word "sporty" here, it is quite scary and very stressful to follow the cars decision, and trying to figure out if it will slow down enough to not slip out in the corner, or if I have to take over and brake, and what is the last moment when I can still brake without causing an accident.

Similar happens almost all the time when I am leaving the highway with Autosteering on the ramp. Red circle number stays 130 correctly, car keeps pushing at 130 where I myself would start to gradually slow down to keep things comfortable for the passangers, then just a moment before I would decide to risk no more and take over, it decreases the blue circled number a little bit and starts to slow down, but still going too fast, a bit later decreases the blue number further, slows further down, but still scaringly fast, then I lose the chicken race with the car and start to press the brake, in order to not crash at the turn at the end of the ramp. But still at a very sporty pace.

I don't know if the car would take this turn without human intervention, or just crash itself, I am not brave enough to try.

So basically the car is choosing the speed in turns and ramps like a racedriver(probably would even crash the car if human doesn't intervene, but sometimes in the middle of the straight road it chooses a low speed for seemingly no reason.

The problem with this that I cannot trust the car, which basically makes Autosteering unusable for
me. Or maybe I am just a very slow driver, and Teslas pace is normal?

Is there any way to systematically handle Autosteering, in a sensible way?

It's there to enhance your driving. If it doesn't do that, you need to override it. If overriding is just too much trouble, then just turn it off and enjoy your drive the normal way.

 

[E90alex]

It is not meant to adjust speed for curves like that or drive how a human would. TACC keeps the set speed. Autosteer tries to keep it centered in the lines. Nothing more than that.

 

[UoMDeacon]

The behavior you want is part of FSD, not the basic Autosteer functions. Autosteer is not meant to be used for onramps and the like.

 

[zoomer0056]

Is your question in regards to Basic Autopilot or FSDb?

 

[bumcurriculum]

Is your question in regards to Basic Autopilot or FSDb?

I have EAP, which in my understanding includes navigate on autopilot, highway ramp to ramp Autopilot. So when I change from one highway to another through a ramp, I have one blue line on the screen, in the middle of the lane, and not two blue lines at the edges of the lane.

 

[bumcurriculum]

It is not meant to adjust speed for curves like that or drive how a human would. TACC keeps the set speed. Autosteer tries to keep it centered in the lines. Nothing more than that.

But it does adjust the speed, that's what makes it unpredictable.
If it would just go with a fix speed only changed because a car in front, that would make it a predictable, normal distance keeping cruise control.

But this is not the case, it is changing the speed, but unpredictably

 

[bumcurriculum]

Also, lane changes are quite interesting with Navigate on Autopilot.
When the car signals the potential lane change into the passing lane, then I tap the turn signal, slightly move the steering wheel(as instructed on screen), then the car nicely and slowly changes the lane. Maybe even too slowly.
However, when the car signals that we need to change lane to the off-ramp lane, then I only need to tap the turn signal without the slight movement of the steering wheel. So far this is fine. BUT then the car - instead of nicely and slowly - changes to the off ramp lane in a totally crazy move, jerking the steering wheel abruptly. Everytime I tried it, I was always afraid that it will crash into the wall next to the ramp. (and then it speeds towards the end of the ramp too fast, as described in my previous post. If it were not slowing at all, I would agree that it is just not supported, but it does slow(blue number gradually decreasing too) , only too late and too little)

I am wondering if it really should work like this.

 

[E90alex]

But it does adjust the speed, that's what makes it unpredictable.
If it would just go with a fix speed only changed because a car in front, that would make it a predictable, normal distance keeping cruise control.

But this is not the case, it is changing the speed, but unpredictably

It’s most likely doing it reactively and not proactively/predictively.

Probably a combination of things including how confident it is in what the cameras are seeing and the measured yaw rate and G forces of the car compared to the calculated/expected yaw rate and G forces based on speed and steering angle. If the computer feels like the car can’t make the turn at the current speed it’s going, then it will start to slow down. And/or if it’s not confident in the lane lines it may slow down.

It is not actively mapping out the the curve and calculating in real time the optimal speed to navigate the curve and optimal lane position in order to achieve maximum comfort.

 

[zoomer0056]

I am wondering if it really should work like this.

Does not seem navigate on autopilot can be trusted at all. Is EAP advertised as beta software?

 

[Dewg]

AP (Autopilot) and EAP (Enhanced Autopilot) use the older AP stack, which is code that hasn't been updated in some time. The new FSD Beta stack, which took over the AP stack on vehicles which subscribe or purchased FSD, handles driving much more smoothly, and does adjust nicely for curves.

 

[bumcurriculum]

Ok, I think I got your point, so the car is slowing down a little to make the crash less severe, which was caused by the driver in the first place.

What contradicts this, is that in some rare cases it does its job quite well: "Or at the end of the highway - where it ends in a 270 degree turn on a ramp - there are speed limit signs at the road, like 80, 60, 40 progressing one after the other. According to the number in the red circle the car recognizes the changing speed limits, but it changes the blue circle numbers differently. (at different places and different speeds, without any clear pattern or correlation with the speed limit)."

At that highway section it starts to slow down in the straight part, of the road and keep slowing down progressively. It goes a little bit above the speed limit, and a little bit above what I would prefer, but most of the local Eastern European drivers use similar speeds there.
Sometimes it slows down before roundabouts, sometimes it doesn't.

I also can't explain the cases when the blue number decreases significantly in the middle of the open highway.

But I think your explanation on the car being reactive still makes the most sense.

 

[bumcurriculum]

Does not seem navigate on autopilot can be trusted at all. Is EAP advertised as beta software?

Navigate on Autopilot is Beta.

The primary aim of my question is that I would like to know if my experience matches the experience of other users or I am doing/understand something incorrectly, or my car might be broken.

 

[bumcurriculum]

It’s most likely doing it reactively and not proactively/predictively.

Probably a combination of things including how confident it is in what the cameras are seeing and the measured yaw rate and G forces of the car compared to the calculated/expected yaw rate and G forces based on speed and steering angle. If the computer feels like the car can’t make the turn at the current speed it’s going, then it will start to slow down. And/or if it’s not confident in the lane lines it may slow down.

It is not actively mapping out the the curve and calculating in real time the optimal speed to navigate the curve and optimal lane position in order to achieve maximum comfort.

At least in the case of changing the lane to the off-ramp, that must be a supported feature on my car, because the car instructs me to use the turn signal to initiate the automatic lane change.

And when I comply and tap the turn signal, then my passengers got the near death experience of an abrupt, jerky lane change at highway speed close to a concrete wall

Anybody else experiencing something similar?

 

[KLam]

NOA on old code do not adjust speed on curves. It will take a curve at current speed. So you have to use the right scroll wheel to slow down when you see a sharp curve coming up or you want to take an exit ramp. It will also not speed up fast enough when merge into fast lanes. So when you want to overtake slow traffic, its better to do it manually (by signal stalk) at speed before the car slows down.

 

[oneday]

Change your speed offset in the autopilot menu to exactly the speed limit or under (I do +10% so not sure if it actually goes negative).

What is your current speed offset in the autopilot menu?

You can also use the scroll wheel to lower speed as you approach turns you don’t like it’s performance.

 

[bumcurriculum]

Change your speed offset in the autopilot menu to exactly the speed limit or under (I do +10% so not sure if it actually goes negative).

What is your current speed offset in the autopilot menu?

You can also use the scroll wheel to lower speed as you approach turns you don’t like it’s performance.

Until now I tried +10%, +10km/h, +5km/h, same results.

I will try 0%, thank you for the hint!

In my 2018 MS unfortunately the speed cannot be changed with the scroll wheel, but by tapping the AP stalk, 5km/h tap, which is not convenient if you need to slow down from 130 to 100, etc.

 

[KArnold]

At least in the case of changing the lane to the off-ramp...then my passengers got the near death experience of an abrupt, jerky lane change at highway speed close to a concrete wall

Anybody else experiencing something similar?

FSDb continues this practice on off ramps as well. I've come to understand that but for others/passengers it is very scary. Definitely on the must fix list.

 

[SidetrackedSue]

It is not meant to adjust speed for curves like that or drive how a human would. TACC keeps the set speed.

I learned in an embarrassing way that TACC does NOT keep the set speed. At least not the version from June 2022.

I was going through highway construction, so was moved down to a single lane with traffic barrels defining both sides of my lane and the lane taking us onto the paved shoulder in places. Autosteer wouldn't even attempt it because of no clear markings (that was understandable). But I set TACC because I have a tendency to drive too slowly at times or too fast at other times (am I looking around, enjoying the view? I slow down; is the road straight and boring? I exceed the limit.) This is the primary reason I've had cruise control on my cars ever since I could afford that feature. The speed limit was 80kph. So my TACC was set to 80kph.

The car was holding the lane well but I thought it was odd I felt comfortable enjoying the view while steering in the narrowed lane. Threading the needle of the barrels wasn't hard work at all. I looked down and I was going 60kph. Looked ahead and realized the car in front of me when I had entered the detoured lane was no-where in sight. On the other hand, there was now a distinct line of vehicles behind me.

Embarrassed that my car was making me appear to be the stereotypical Little Old Lady Driver, I sped up to the speed limit and was forced to drive that section of the road fully on my own since the car had overridden the TACC speed and slowed the car down too much.

The lesson learned: I could choose to drive the car fully on my own, or let the car make ALL decisions for me that it wanted to make. It didn't want to make lane centering decisions, so it handed me that job, but when it didn't like the speed limit I set, it slowed the car down. It made a decision I (and the people behind me) found unacceptable and so I was forced to drive the car as if it didn't have even the basic cruise control.

On TACC the car is making speed decisions so it doesn't hit a car traveling slowly in front of me. It isn't a 'dumb' mechanical mechanism.

I miss that mechanical mechanism that let me 'program' my car, know the speed I set, and take responsibility for making changes to that setting. Now when I 'program' TACC, it is only to suggest what I want it to do and then I have to constantly monitor that it isn't failing at the task assigned. That makes more work for a driver, not the driver-assist I thought I was getting. It is entirely possible the screen had flashed a warning it was slowing the car down so I can't say I wasn't notified visually but since the car had refused to do the steering, I was busy steering, thus not looking over at the screen to check my speed. I had set my speed, so I assumed the car was going that speed. There was no audio warning and no refusal from the car to accept 80kph as the speed set, it just refused to maintain the speed set.

This was just part of my unacceptable four day long distance drive of 3500km that I felt confident undertaking on my own because I now owned a car with multiple driver assist features to reduce the strain of the two day drive in each direction. This was before FSDb but autosteer was unavailable a lot of the time that I needed it (too dark, too foggy, heavy rain), the wipers on 'auto' weren't meeting my needs, the defrost required me (in fog and no autosteer) to turn my attention to the screen to try and get it to work properly, and then the TACC wouldn't maintain my speed. On top of all that, the navigation system was unreliable on multiple occasions, leading to detours since I followed it (in the fog) instead of following the proper route. Without autosteer for so much of the drive, I was unable to look at the screen to figure out WTF the NAV was thinking, especially when the instructions didn't match the line on the map or my knowledge of the route (one that I've taken dozens of times in my life.)

So much for my great car with the latest and greatest tech and driver assist features. This drive cemented my hate for the vehicle and no subsequent update has come close to convincing me the car's programming can be relied upon, even for something as simple as wipers and TACC.

Back to OP's issue, in my case TACC did slow down for a situation, in other words the complete opposite experience to OP. I wasn't on EAP, so I have no idea if it would have slowed down had I been able to set Autosteer, but my takeaway is I can't trust TACC to maintain the speed set. I've never seen it exceed the speed set, but like OP I have experienced it NOT slowing down for extreme curves so I am prepared to override for that. I just didn't expect the car to override my set speed and slow down below what was required for lane design and conditions.

 

[bumcurriculum]

There was no audio warning and no refusal from the car to accept 80kph as the speed set, it just refused to maintain the speed set.

I am happy you mentioned the lack of any sound and light signals when the AP apparently acts in a "reactive way".

So if we assume that in my case the too late and too shy speed decreases at curves are because of reactive driving by the AP (instead of driving proactively, because I haven't paid for FSD), so basically the AP is doing last resort crash avoidance, then I would expect the car to give me audio and visual alarms and maybe deactivate autosteering, like most of the driver assistance systems work when the driver appears to drive recklessly.
My main problem that this doesn't happen. The AP is speeding happily into the death of its passangers, without any warnings, just as everything happened as it should. Even slowing a bit down, but not enough. I just realized this is the main reason why I am totally puzzled by the way how AP works, I never know what is happening at any time is normal, emergency or AP just malfunctions. Just no feedback from the system.