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Thoughts on phantom breaking after a 5800 mile roadtrip

buyleonard

Member
Jan 4, 2020
110
130
Oregon
I recently completed a 5800-mile round trip from Portland, OR to Lafayette, LA. I have a June 2021 Vision only Model Y, and I used Autopilot as much as possible. Loved the car and wouldn’t have been doable by me without Autopilot.

On the way there I used the latest production version (can't remember the version number). Driving through California I was experiencing phantom breaking more often than I was used to until I remembered that I had changed some of the settings for the trip, so I changed back to using current speed instead of speed limit and turned off red light detection. It seemed to reduce the breaking, and what I did have wasn't serious.

Before I left for the return trip, I received the FSD Beta and so I drove back using 10.4. At first it seemed that phantom breaking was about the same, but once I hit some of the emptier stretches of the freeway, I had a lot of phantom breaking, and it was a lot more severe.

1) The first one wasn't even in Autopilot, I was driving manually and entering a construction zone where the 2 lanes of freeway was going down to 1, I was in the lane that kept going with the other lane blocked off by cones, the collision warning went off and the car braked hard enough to lock the seat belt and make my chest sore from the belt. Since I have the beta, I hit the camera report button (and sent email to Tesla) and did a dashcam recording.

2) I turned off forward collision warning, had another hard breaking event while in Autopilot, again with the alarm that I associate with forward collision alarm. So not wanting it to happen again, I turned off emergency breaking (the one that you must turn off every time you start driving) and left it off for the rest of the trip.

3) Had a 3rd hard breaking event, again on Autopilot.

After these 3 events (and many less serious phantom breaking occurrences) I came up with the following:

For the 3 hard breaking events, at least 2 of them (1st and 3rd, not sure about the 2nd) happened right where a previous driver had slammed on their breaks and left skid marks that veered to the right. Both events happened right at the beginning of the skid marks.

If I follow someone, doesn’t even need to be close, as long as I can see the car on the monitor, I never had any kind of phantom break. All the breaking events occurred when I had an empty road in from of me. I figured this out with more than half the trip home left, so by always making sure that someone was in front of me, I drove about 1500 miles without any phantom breaking.

Normally I'm not a fast driver, and I usually just find someone close to the speed I want to go, preferably an 18-wheeler, and follow them. Wondering if that's why I don't usually experience much in the way of phantom breaking.

Thoughts?
 

mark95476

Active Member
Jun 21, 2020
2,067
1,589
Bay Area CA
I rarely get phantom braking, but I'll try keeping this in mind. I'm generally passing people, however, AP/FSD is making me a more patient driver.

It makes sense that if the car sees the leading car proceeding safely then it can discount any spurious road hazards that might trigger phantom braking.

If I follow someone, doesn’t even need to be close, as long as I can see the car on the monitor, I never had any kind of phantom break. All the breaking events occurred when I had an empty road in from of me. I figured this out with more than half the trip home left, so by always making sure that someone was in front of me, I drove about 1500 miles without any phantom breaking.

Normally I'm not a fast driver, and I usually just find someone close to the speed I want to go, preferably an 18-wheeler, and follow them. Wondering if that's why I don't usually experience much in the way of phantom breaking.

Thoughts?
 

tripnine

New Member
Dec 19, 2021
1
0
Kansas City
Very helpful, thanks for sharing.

I’m about to receive delivery on my first Tesla, a Model Y long range, and I’ve been apprehensive about phantom braking…

Your post helps me understand the problem much better and also how to mitigate it while Tesla engineering continues to work on improving AD/FSD.
 

CaseyL

Member
Jul 3, 2021
48
51
Florida
After these 3 events (and many less serious phantom breaking occurrences) I came up with the following:

For the 3 hard breaking events, at least 2 of them (1st and 3rd, not sure about the 2nd) happened right where a previous driver had slammed on their breaks and left skid marks that veered to the right. Both events happened right at the beginning of the skid marks.

I've had something similar happen when approaching a short section of 4-lane divided highway which had been patched and was much darker.

If I follow someone, doesn’t even need to be close, as long as I can see the car on the monitor, I never had any kind of phantom break. All the breaking events occurred when I had an empty road in from of me. I figured this out with more than half the trip home left, so by always making sure that someone was in front of me, I drove about 1500 miles without any phantom breaking.

Normally I'm not a fast driver, and I usually just find someone close to the speed I want to go, preferably an 18-wheeler, and follow them. Wondering if that's why I don't usually experience much in the way of phantom breaking.

Thoughts?

This is and interesting and very helpful observation. I just drove 300 miles yesterday and the most peaceful part of the trip was while driving on I-10 with TACC & Autosteer on while following another car who happened to be going my desired speed. Apparently the software places a high value on what the vehicle in front is doing. Like you said, all of my phantom breaking events seem to happen with an empty lane in front of me.

I have encountered phantom breaking on 2 lane highways when the lane in front of was empty but a large truck was approaching in the oncoming lane. I am wondering, what would happen if I was following another vehicle in that case? My guess is that having the other vehicle in front would prevent the braking even with the large truck approaching.
 
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Made two 2-lane 60 mile trips in the past 2 days. Both days had lots of vehicles in each direction, but since I drive the speed limit, I never had anyone close in front of me. EVERY TIME I enabled TACC (mainly to give my foot a break for awhile--AP & FSD were not enabled) if a semi approached in the opposite direction, my 2021 M3 LR would suddenly brake hard (say 60 to maybe 20), sound the beeping alarm (which scares my wife to death), and swerve to the right. After the first day's nightmare, I tried disabling all the possible alarming conditions. No change on the second day, except I was on to it this time. I gave my wife a heads up when the first two semis approached and the same hard braking, alarms and evasive steering occurred (with no one behind us, thankfully). For the rest of the trip, I turned on TACC when there were no semis in sight and then turned it off when I saw one (or more) approaching. Definitely a kludge approach, but it did give my foot and ankle a break for some intermittent periods of time.
 
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Sporty

Member
Supporting Member
Apr 20, 2019
417
412
Seattle
I recently completed a 5800-mile round trip from Portland, OR to Lafayette, LA. I have a June 2021 Vision only Model Y, and I used Autopilot as much as possible. Loved the car and wouldn’t have been doable by me without Autopilot.

On the way there I used the latest production version (can't remember the version number). Driving through California I was experiencing phantom breaking more often than I was used to until I remembered that I had changed some of the settings for the trip, so I changed back to using current speed instead of speed limit and turned off red light detection. It seemed to reduce the breaking, and what I did have wasn't serious.

Before I left for the return trip, I received the FSD Beta and so I drove back using 10.4. At first it seemed that phantom breaking was about the same, but once I hit some of the emptier stretches of the freeway, I had a lot of phantom breaking, and it was a lot more severe.

1) The first one wasn't even in Autopilot, I was driving manually and entering a construction zone where the 2 lanes of freeway was going down to 1, I was in the lane that kept going with the other lane blocked off by cones, the collision warning went off and the car braked hard enough to lock the seat belt and make my chest sore from the belt. Since I have the beta, I hit the camera report button (and sent email to Tesla) and did a dashcam recording.

2) I turned off forward collision warning, had another hard breaking event while in Autopilot, again with the alarm that I associate with forward collision alarm. So not wanting it to happen again, I turned off emergency breaking (the one that you must turn off every time you start driving) and left it off for the rest of the trip.

3) Had a 3rd hard breaking event, again on Autopilot.

After these 3 events (and many less serious phantom breaking occurrences) I came up with the following:

For the 3 hard breaking events, at least 2 of them (1st and 3rd, not sure about the 2nd) happened right where a previous driver had slammed on their breaks and left skid marks that veered to the right. Both events happened right at the beginning of the skid marks.

If I follow someone, doesn’t even need to be close, as long as I can see the car on the monitor, I never had any kind of phantom break. All the breaking events occurred when I had an empty road in from of me. I figured this out with more than half the trip home left, so by always making sure that someone was in front of me, I drove about 1500 miles without any phantom breaking.

Normally I'm not a fast driver, and I usually just find someone close to the speed I want to go, preferably an 18-wheeler, and follow them. Wondering if that's why I don't usually experience much in the way of phantom breaking.

Thoughts?

How many people were in the car? I find my tolerance for phantom breaking goes down when I have any passengers present.

Good info about having a car in front. I’ll give it a shot.
 
I recently completed a 5800-mile round trip from Portland, OR to Lafayette, LA. I have a June 2021 Vision only Model Y, and I used Autopilot as much as possible. Loved the car and wouldn’t have been doable by me without Autopilot.

On the way there I used the latest production version (can't remember the version number). Driving through California I was experiencing phantom breaking more often than I was used to until I remembered that I had changed some of the settings for the trip, so I changed back to using current speed instead of speed limit and turned off red light detection. It seemed to reduce the breaking, and what I did have wasn't serious.

Before I left for the return trip, I received the FSD Beta and so I drove back using 10.4. At first it seemed that phantom breaking was about the same, but once I hit some of the emptier stretches of the freeway, I had a lot of phantom breaking, and it was a lot more severe.

1) The first one wasn't even in Autopilot, I was driving manually and entering a construction zone where the 2 lanes of freeway was going down to 1, I was in the lane that kept going with the other lane blocked off by cones, the collision warning went off and the car braked hard enough to lock the seat belt and make my chest sore from the belt. Since I have the beta, I hit the camera report button (and sent email to Tesla) and did a dashcam recording.

2) I turned off forward collision warning, had another hard breaking event while in Autopilot, again with the alarm that I associate with forward collision alarm. So not wanting it to happen again, I turned off emergency breaking (the one that you must turn off every time you start driving) and left it off for the rest of the trip.

3) Had a 3rd hard breaking event, again on Autopilot.

After these 3 events (and many less serious phantom breaking occurrences) I came up with the following:

For the 3 hard breaking events, at least 2 of them (1st and 3rd, not sure about the 2nd) happened right where a previous driver had slammed on their breaks and left skid marks that veered to the right. Both events happened right at the beginning of the skid marks.

If I follow someone, doesn’t even need to be close, as long as I can see the car on the monitor, I never had any kind of phantom break. All the breaking events occurred when I had an empty road in from of me. I figured this out with more than half the trip home left, so by always making sure that someone was in front of me, I drove about 1500 miles without any phantom breaking.

Normally I'm not a fast driver, and I usually just find someone close to the speed I want to go, preferably an 18-wheeler, and follow them. Wondering if that's why I don't usually experience much in the way of phantom breaking.

Thoughts?
I have had my own share of phantom braking events, almost always with oncoming traffic on 2-lane highways (especially tall vehicles like semi trucks or RVs). There is a very kludgy workaround: if you can anticipate the issue you can press the accelerator, which defeats automatic braking. But that's hardly an excuse for a pretty dangerous behavior in the software.
 
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buyleonard

Member
Jan 4, 2020
110
130
Oregon
Just finished a trip from Portland to San Diego to Phoenix, and then back to Portland with FSD 10.8, all most all freeway and almost all it during daylight hours. I didn't experience any phantom breaking even when I wasn't following anyone, so much improved. I still haven't tried it much on 2 lane highways.

Hopefully no more long driving trips for a while :).

On a side note, my wife drove to Seatle yesterday in the rainstorm, and said cruise control wasn't usable, kept giving her the mesaage about poor visibility. She doesn't use autopilot.
 
I've had something similar happen when approaching a short section of 4-lane divided highway which had been patched and was much darker.



This is and interesting and very helpful observation. I just drove 300 miles yesterday and the most peaceful part of the trip was while driving on I-10 with TACC & Autosteer on while following another car who happened to be going my desired speed. Apparently the software places a high value on what the vehicle in front is doing. Like you said, all of my phantom breaking events seem to happen with an empty lane in front of me.

I have encountered phantom breaking on 2 lane highways when the lane in front of was empty but a large truck was approaching in the oncoming lane. I am wondering, what would happen if I was following another vehicle in that case? My guess is that having the other vehicle in front would prevent the braking even with the large truck approaching.
CaseyL you nailed it: Lot of Texas Driving XMas 2021 - 2022 M3LR Mfg 11/21 - No FSD - just TACC/AP (Adaptive Cruise and lane keep assist)
1. Day is better than night
2. Highways with large median separation is better than 2 lane high speed roads with no separation
3. Height of the oncoming vehicle (?perceived mass? -18 wheeler) is far worse than a Full size F-250/350
4. Overpasses with metal reflective markers / barricades left and right side of road are high probability phantom breakers at night and day.
5. Angle off attack from inclines and declines seems to make the pavement out to be 18 wheelers
6. Sharper Curves in the 2 lane roads are high probability.
7. Passengers and dogs get really upset or spooked with phantom breaking and the remedy appears to be be use it and cover the go pedal at all times mentioned above which ultimately resulted in full turn off mode at night on 2 lane high speed (50-70 mph posted) roads. Tesla has some serious work to do on Adaptive Cruise Control !!!
8. Tested all the above both with TACC only and TACC/AP and it appears it 99% related only to TACC.
 

jdjeff88

Member
Aug 25, 2016
229
303
Texas
I find that with my new S the problem of driving on Autopilot adjacent to an HOV lane has become substantially worse. I drive the same route south of Houston twice a week and with my S Performance had no issue. Picked my plaid last week with V11 and now I can't use Autopilot. Everytime I pass a sign on the HOV lane--even if I move three lanes away--the car picks up and applies that speed limit. So the car goes from 80 to 40 or 50 or 60 slamming on the brakes. I've been almost rear ended multiple times. This in addition to true phantom braking which also happens. No more Autopilot for me.
 

buyleonard

Member
Jan 4, 2020
110
130
Oregon
the car picks up and applies that speed limit
Won't it only do this if you have Cruise set to Speed Limit (in Autopilot settings)? I set upt two profiles, one with FSD when I want to play with it, and the other with just Autopilot. On the one with just Autopilot, I set it to Current Speed instead of Speed Limit, and I turn off stopping for traffic lights. I find that it works much better / predicable with those settings.
 

adewinne

Member
Supporting Member
Mar 15, 2020
13
9
Toronto, Ontario
I owned a 2020 Model Y FSD so I know how it's supposed to operate. I now own a new 2022 Model Y FSD that I've had for just over 1,000km and FSD worked much better on my 2020. The 2022 car keeps telling me one or more cameras are blocked and tells me there is poor visibility when in reality the cameras are not blocked, and the visibility is fine. Consistently when I drive past a large truck thats in the oncoming lane the car will apply brakes and sometimes make a warning sound before going back up to speed.

I made a little video of the issue to illustrate the problem. In this vid, it wasn't even a truck, just a car. 2022-01-09 FSD phantom braking madness
 
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Just give me plain old "dumb" cruise control until this is worked out.
Amen. I drive 120 miles a day and I can’t live without CC. My 2 month old model 3 is driving me nuts. I just want all of the nanny aids turned off. It’s not just about going too slow (although this is an issue too), CC is just flat out dangerous.
 
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…while Tesla engineering continues to work on improving AD/FSD.
That’s the joke of the year right here. Sorry perhaps you’re new to Tesla. I’ve owned teslas for YEARS now. My autopilot on my ‘16 MS still has bugs and braking issue. Not as awful as my MY but you can see it’s almost 6 year old car still suffering from software issues that should have been resolved years ago. As ardently I used believe in Tesla I absolutely hate this company now and have zero faith and especially Elon to push Tesla to do the right thing. Sorry to burst your bubble though as you’re going in for your new Tesla.

I own two of them and shame on me for not learning my lesson. But never again.
 
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linux-works

Active Member
Dec 23, 2019
2,295
4,365
mtn view, ca
it is such a hard problem, to ensure that auto-braking is fast when you need it, but does not trigger falsely, otherwise.

I bet you could have a whole company do research on this and they would still have trouble getting it right enough to be good enough for daily use.

so many areas are harder than it seems. lane centering has a lot to deal with, planning for what is near-ahead, mid-ahead and far-ahead. trying to read minds of other drivers. on and on.

this is going to be something even harder than a moonshot. there were no random crazy drivers on the way to the moon - amiright? ;)

seriously, one single company trying to write all their own software. FAIL. this just is a mankind-wide effort, more so than even the moonshots of the past.

and yet, I dont see any real collaboration. everyone thinks they can solve this very hard problem on their own.

but tesla, especially, in their arrogance, are taking big steps instead of safer small ones.

I hope that someday we can pool resources - as a whole human race - and divide this up and solve it in pieces. and it will still take all of mindkind to think about this and work on it for years, maybe decades.

baby steps are what we need. lane centering is a huge step forward. and it mostly works. braking - its not even alpha quality let alone beta. they need a whole division working on that.

and NN is not the answer. we need to find deeper levels of understanding than statistics, which is all NN really is. that's NOT understanding and that's not enough to drive a car in a crowded random human-filled environment.
 
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Sporty

Member
Supporting Member
Apr 20, 2019
417
412
Seattle
That’s the joke of the year right here. Sorry perhaps you’re new to Tesla. I’ve owned teslas for YEARS now. My autopilot on my ‘16 MS still has bugs and braking issue. Not as awful as my MY but you can see it’s almost 6 year old car still suffering from software issues that should have been resolved years ago. As ardently I used believe in Tesla I absolutely hate this company now and have zero faith and especially Elon to push Tesla to do the right thing. Sorry to burst your bubble though as you’re going in for your new Tesla.

I own two of them and shame on me for not learning my lesson. But never again.

I agree that it’s a leadership problem. The software team needs help (re-org, new leadership). The killer is that there is seems mostly (but not totally) limited to this area. Eg imagine if the folks building the hardware were as talented as the sw team… the doors would be falling off without a fix. I don’t know why some of the other team leaders aren’t insisting that something be done.
 
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