Phantom Braking

[farmerj]

Google is your friend.

https://www.reddit.com/r/teslamotors/comments/sj9j80

Looks like it's braking for shadows... too bad there's no radar to confirm...

 

[2101Guy]

Interesting, I would use AP only on the Interstate and not on a single-line traffic like this. Makes sense that the car brakes because of oncoming traffic from the other lane. Am I missing anything?

How are we to get from "NYC to LA with no human intervention by 2019" solely on interstates if there is a detour? Elon says FSD will be BETTER than humans in 11 months. Humans typically can handle all sorts of roads..

 

[CarlThompson]

An experienced user here pointed out to me that the manual states AP is only to be used on interstates and highways ...

I think there is a language issue here. In large parts of the United States, particularly in the east, the word "highway" is used almost exclusively by drivers to refer to a specific type of highway with high speeds, no intersections and controlled access (on and off ramps). However, the word actually is much more general and applies to pretty much any road that goes long distances (multiple miles) particularly (but not necessarily) if it has multiple lanes in one direction or a higher speed limit.

Here in California (where the Tesla manual is presumably written), we use the word "highway" in the broader sense and we use the word "freeway" to refer to the same type of road that people in the east refer to as a "highway." However, in large parts of the country they don't use the word "freeway" at all. To complicate things back east (at least when I lived there 20+ years ago) the departments of transportation, motor vehicle agencies and city planners use the broader definition of "highway" that is unfamiliar to their drivers. For example, when I took my driver's test in Maryland 30+ years ago it was clear that the test and the teaching material use the word "highway" much more broadly to include even roads with a single lane in each direction that had stoplights and stop signs. You will also see plenty of roads in the east called "Something Highway" that drivers would not actually consider highways by their definition.

I just searched through the current Tesla manual and it's clear they are aware of this language problem. The manual specifically introduces the term as "controlled-access highway" in every place where they are talking about what drivers in many parts of the country including the east call "highways" and what we in California call "freeways." In the areas where the manual simply uses the word "highway" alone without the "controlled-access" qualifier they appear to be using in the broader sense of word which includes roads with cross streets and flow controls.

Finally, Tesla uses the term "Autopilot" to include two completely separate systems: Autosteer and Traffic Aware Cruise Control. There is no usage guidance for Autopilot as a whole; the manual describes and gives usage guidelines for each of those systems separately.

An experienced user here pointed out to me that the manual states AP is only to be used on interstates and highways ...

So to unpack all that and get back to what you wrote I believe this is incorrect for two reasons. First, the current manual does not give usage guidance for Autopilot as a whole (just separate guidance for the individual components). Second, I believe your understanding of the word "highway" is different than the way the manual uses it in the section about Traffic Aware Cruise Control (TACC).

In the video, the user is talking about phantom braking. Nowhere does he talk about problems with lane keeping so I think it's fair to infer that he is specifically calling out an issue in TACC. The section of the current manual describing TACC usage guidelines says this:

Traffic-Aware Cruise Control is primarily intended for driving on dry, straight roads, such as highways.

Note two things: First, the manual uses the word "highway" alone instead of using the term "controlled-access highway" which they appear to use in every section where they are specifically talking about what you may think of when you hear the word "highway." But I believe this is a purposeful decision and the road the poster is driving on does qualify as a "dry, straight roads, such as [a] highway." Secondly and perhaps most importantly, the manual uses the words "primarily" and "such as." To me this clearly means that the manual does not intend to restrict the usage of TACC to highways but is simply using highways as an example!

So the short version is my reading of the manual does not at all support what this other user told you.

... the manual states AP is only to be used on interstates and highways...where all the traffic is going in the same direction and there are no cross streets. Using AP on a road with opposing traffic and cross streets is dangerous.

TL;DR version: The manual does not say any of that.

 

[buyleonard]

Adaptive Cruise from other brands and Tesla's are trying to do two different things. Adaptive Cruise from other brands are just using radar, which allows them to be really good at following a moving car, but not so much stopping for a stopped car. I'm guessing, but all of these systems would probably run into the white truck stopped on the road like early Teslas did. Tesla is trying to solve the harder problem, with their Adaptive Cruise control stopping or slowing down for all possible issues, because they want to achieve FSD. So initially it was worse, but I've noticed that on my Vision only with FSD Beta, phantom breaking has gotten much better. And it will continue to improve, unlike other brands. And yes, it is annoying sometimes, but that is the cost of progress.

 

[CarlThompson]

On all the vehicles I've driven that have adaptive cruise or traffic assist systems, they also have the good old fashioned maintain speed you set cruise control as an option as well.

None of the vehicles I've driven with adaptive cruise control allowed you to use non-adaptive cruise control (at least not without jumping through some hoops). Not allowing it makes sense to me; it would be too easy for drivers to confuse themselves and enable regular cruise control thinking it was adaptive cruise control, let their focus lapse a little and unintentionally hit the car in front or have an unpleasant AEB experience.

 

[_jal_]

Adaptive Cruise from other brands and Tesla's are trying to do two different things. Adaptive Cruise from other brands are just using radar, which allows them to be really good at following a moving car, but not so much stopping for a stopped car. I'm guessing, but all of these systems would probably run into the white truck stopped on the road like early Teslas did. Tesla is trying to solve the harder problem, with their Adaptive Cruise control stopping or slowing down for all possible issues, because they want to achieve FSD. So initially it was worse, but I've noticed that on my Vision only with FSD Beta, phantom breaking has gotten much better. And it will continue to improve, unlike other brands. And yes, it is annoying sometimes, but that is the cost of progress.

Not to nitpick, but Subaru's system is vision-only

 

[technobabbler]

I am absolutely experiencing phantom braking as described above. The argument that it should not be used on a two lane road doesn't hold any water in my opinion. Several county roads where I live are long stretches that are straight and not hilly of nothing but 1 lane each way with a speed limit of 80km/hr (traffic is usally 90-100km/hr). There is no reason (barring the phantom braking that I am experiencing) to not use cruise control on a road like this. I am talking about TACC not autopilot or FSD. I've owned and driven several vehicles with adaptive type cruise control (albeit all radar based) on these roads and experienced no problem with them. There is no reason in my mind that a car in the M3's price bracket shouldn't have a perfect cruise control. The argument might hold some merit if I was participating in the FSD beta which I am not as it's a beta and not in production.

 

[DocRob]

I have experienced several episodes of phantom braking. As well, in general, there is way too much hard braking. There is no way that FSD beta would obtain the safety scores that drivers needed to get the FSD software download. I rarely use the friction brakes. I can usually glide to a stop with maybe slight tweaking of thhe accelerator pedal. I plan to never need brake pads. No way current FSD could do this.

 

[sleepydoc]

Exactly, any variation of cruise control whether it is on Tesla or any other car should be used on the interstate or highway where traffic is flowing in the same direction. Using it on roadways with oncoming traffic is dangerous.

Absolutely false. What makes cruise control unsuitable for roads besides interstates? Nothing.

None of the vehicles I've driven with adaptive cruise control allowed you to use non-adaptive cruise control (at least not without jumping through some hoops). Not allowing it makes sense to me; it would be too easy for drivers to confuse themselves and enable regular cruise control thinking it was adaptive cruise control, let their focus lapse a little and unintentionally hit the car in front or have an unpleasant AEB experience.

Except none of the vehicles I’ve used with adaptive cruise control have issues with phantom braking like Teslas do. If TACC was reliable I wouldn’t want ‘plain’ cruise control in my car but the constant phantom braking makes it necessary.

I’ve had phantom braking occur on interstates, state highways and side roads. Daytime and night time. Busy roads and completely empty roads.

The fact is phantom braking is absolutely a problem and none of the excuses made here fully explain the problem or really matter. It should work. Period. Just like every other car on the road.

 

[Charlesdteal]

I have owned a 2019 Model 3 & a 2019 Model S which neither had a big problem with Phatom braking. I understand it has to do with the new Tesla Vision and not having the radar. I have had a new Model S ordered since early July 2021 which has not been delivered yet (who knows if it ever will get delivered). I see all of the post about phantom braking but they are all either in the Model 3 or the Model Y. I don't see anyone posted a problem with it in a newer Model S or Model X that is using Tesla Vision. If this also a problem in the Model S & Y that have Tesla Vision and no radar?

 

[T4M3]

Absolutely false. What makes cruise control unsuitable for roads besides interstates? Nothing.

You can use it but it is still dangerous with oncoming traffic and crossroads.

 

[2101Guy]

I have experienced several episodes of phantom braking. As well, in general, there is way too much hard braking. There is no way that FSD beta would obtain the safety scores that drivers needed to get the FSD software download. I rarely use the friction brakes. I can usually glide to a stop with maybe slight tweaking of thhe accelerator pedal. I plan to never need brake pads. No way current FSD could do this.

Its ironic that multiple forum members have posted a decrease in their score or inability to get higher score, solely due to FSD phantom/hard braking for no reason at all in many cases.

The irony that the safety score is impacted...by the system that requires a high safety score. LOL

 

[2101Guy]

You can use it but it is still dangerous with oncoming traffic and crossroads.

There was at least one video posted here on this forum showing FSD Beta crossing over double yellow lines at same spot in the road every day for one of the forum members. For zero reason at all. Fortunately no cars or vehicles were approaching other wise high chance of head on collision

 

[CarlThompson]

You can use it but it is still dangerous with oncoming traffic and crossroads.

Do you mean TACC is dangerous in those situations in general as a concept or dangerous as currently implemented by Tesla because of all the phantom braking being reported? I personally don't see anything inherently dangerous about the concept of TACC in those situations but would agree with you if what you're saying is that TACC as currently implemented by Tesla could be dangerous.

 

[sleepydoc]

And right on cue - I was driving into Minneapolis on I394. Low to moderate traffic, traveling at or above posted speeds. On 3 occasions my car suddenly brakes for no reason. No car in front of me for at least 200 feet, no cars merging, all traffic moving well.

 

[enemji]

Google is your friend.

https://www.reddit.com/r/teslamotors/comments/sj9j80

These are all instances when I would have slowed down myself. I think AutoPilot is aligned to my thinking, amd not the hard and fast drivers.

 

[enemji]

Its not just AP being shown, its also Tesla's version of adaptive cruise control. If its a 50-60mph roadway with minimal traffic, why not use cruise control? How does it make sense that the car would brake for oncoming traffic from the other lane ONLY when its a truck?

Cuz trucks are known to create drafts like a big ship in water. Duh.

 

[enemji]

And right on cue - I was driving into Minneapolis on I394. Low to moderate traffic, traveling at or above posted speeds. On 3 occasions my car suddenly brakes for no reason. No car in front of me for at least 200 feet, no cars merging, all traffic moving well.

Either the system has a bug or it is safer driver than you are.

 

[sleepydoc]

You can use it but it is still dangerous with oncoming traffic and crossroads.

Just how would it be dangerous? You need to pay attention whether it’s you or the car pressing the accelerator and you’re not going to suddenly swerve into oncoming traffic just because you have cruise control on.

 

[sleepydoc]

Cuz trucks are known to create drafts like a big ship in water. Duh.

And we’re supposed to brake for the draft of the truck? How often do you brake when you’re on. 2 lane road and a truck passes going through other direction? Maybe think about your answers before posting them.

Either the system has a bug or it is safer driver than you are.

Well, since every other car on the road kept going at the same speed ( except for the guy behind me) it would appear that the system has a big, wouldn’t it. Of course that’s what this thread is all about.