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Autopilot Error - Following Car in Adjacent Lane

autopilot.jpg

I'm not sure if there is another thread specific to this issue, as I haven't been able to locate one.

As you can see in the picture I took last night, my car is thinking that the car all the way in another lane is my "follow car" which you can tell because the car is dark gray on the display.

In this instance, there is not a shadow on the road or anything to exponentially confuse the visuals, so I am having trouble figuring out why my car is viewing the situation this way. It is also not even close to the line, and it's a double white HOV line! My display even shows the car in the appropriate lane... this is just super weird

Anyone else experiencing this and have ideas on why it's happening? or just a bug..
 

ecarfan

Well-Known Member
Moderator
As you can see in the picture I took last night, my car is thinking that the car all the way in another lane is my "follow car" which you can tell because the car is dark gray on the display.
I see what you are describing, but would like to point out that in fact your car does not appear to be tracking that car to the right because you are almost directly adjacent to it while on TACC meaning your following distance is about zero, which TACC would not allow.

I see that TACC was set to 66 but your speed at the time of the photo was 55. At the time of the photo was your car accelerating in an attempt to reach the set speed or was it staying at 55?

Your display doesn’t show any cars ahead of you in your lane; is that what you noticed?
 

woodisgood

Optimustic Pessimist
Jul 26, 2018
3,065
18,634
San Francisco
Don’t want to get ahead of ourselves, but I have often hoped that Tesla will ultimately start taking adjacent vehicles into account to get a more “global” idea of traffic flow. Focusing on just one follow car can sometimes lead to accelerations that are more sudden and severe than is safe for the overall flow.
Also generally avoiding sitting in blind spots is another requested behavior.

Could be that the dark gray is indicating that your car is actively monitoring the other vehicle for reasons similar to above, rather than “following” it per se.
 
Just to clarify, your car didn’t alter its behavior based on this, you’re concerned that the adjacent vehicle was dark gray?
My car did alter its behavior. it slowed down and wouldn't pass the car because it was in "follow mode" while not even in the same lane - i had to press the accelerator manually to pass by and then the car in the display went back to light gray, indicating it was no longer "following" that car then it was all was fine.
 
I see what you are describing, but would like to point out that in fact your car does not appear to be tracking that car to the right because you are almost directly adjacent to it while on TACC meaning your following distance is about zero, which TACC would not allow.

I see that TACC was set to 66 but your speed at the time of the photo was 55. At the time of the photo was your car accelerating in an attempt to reach the set speed or was it staying at 55?

Your display doesn’t show any cars ahead of you in your lane; is that what you noticed?
no, the car slowed down to "follow" the car in the adjacent lane - i was taking this picture while simultaneously pressing the accelerator to pass it, that is why it appears that the follow distance is so close. it was in fact keeping me at a distance from where it "thought" the car was positioned in my lane. kind of hard to explain, but the dark gray indicates that it does in fact want to follow that car, but should only be doing this if my car is in that lane.
 
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woodisgood

Optimustic Pessimist
Jul 26, 2018
3,065
18,634
San Francisco
My car did alter its behavior. it slowed down and wouldn't pass the car because it was in "follow mode" while not even in the same lane - i had to press the accelerator manually to pass by and then the car in the display went back to light gray, indicating it was no longer "following" that car then it was all was fine.

Weird. How long was it following for?
 
I’ve had this happen to me once or twice.

In some instances, it seems to think the car is going to move into your lane or something so it goes grey, and makes your car brake.

Not sure why either, but seems to have started on the last update or so.

I suspect this is a result of the progression to capture edge cases for autopilot.
It happens so infrequently, it’s not a big deal.

First world problems of running and testing brand new tech for self driving.

Keep your eyes on the road and carry on. :)
 
Don’t want to get ahead of ourselves, but I have often hoped that Tesla will ultimately start taking adjacent vehicles into account to get a more “global” idea of traffic flow. Focusing on just one follow car can sometimes lead to accelerations that are more sudden and severe than is safe for the overall flow.
Also generally avoiding sitting in blind spots is another requested behavior.

Could be that the dark gray is indicating that your car is actively monitoring the other vehicle for reasons similar to above, rather than “following” it per se.
totally understand where you are coming from - but i was in the HOV lane going 66 and was slowed down to 55 and essentially "blocked" by the car in the other lane even though it was far off to the right, i had to manually accelerate past.

Granted, this usually doesn't happen, I usually fly by on my merry way past cars going much slower in the adjacent Non-HOV lane as per usual, this specific instance has happened a few times though so i am just trying to figure out why... there may not be an answer other than a bug.
 

mtndrew1

Active Member
May 12, 2015
1,501
4,410
Gardena, CA
It may be that your car thought it was about to come into your lane, and it was trying to let it in.

I think what’s happening here is that they goofed up the maps and the car thinks the adjacent lane will soon be merging into the lane I’m occupying, therefore the car has targeted the cars to prepare for the merge.

This happens to me on the same spot every single day on my commute and began immediately following the most recent map download. It’s exactly the same behavior as when lanes are merging together.
 

C141medic

Active Member
Apr 9, 2016
1,714
1,582
New Jersey
View attachment 453779
I'm not sure if there is another thread specific to this issue, as I haven't been able to locate one.

As you can see in the picture I took last night, my car is thinking that the car all the way in another lane is my "follow car" which you can tell because the car is dark gray on the display.

In this instance, there is not a shadow on the road or anything to exponentially confuse the visuals, so I am having trouble figuring out why my car is viewing the situation this way. It is also not even close to the line, and it's a double white HOV line! My display even shows the car in the appropriate lane... this is just super weird

Anyone else experiencing this and have ideas on why it's happening? or just a bug..
I had the same exact thing happen about a month ago on the NJTPK. I was in the far left lane with no one in front of me. A vehicle in the adjacent lane (to the right) began to speed up and my car decided to immediately slow down. It appeared that autopilot/NOA or whatever started tracking the adjacent vehicle. I had to step on the accelerator so I wouldn’t get rear ended.
 
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ecarfan

Well-Known Member
Moderator
Thank you, now I understand your situation better. That is very strange behavior. I have never seen it in my Model 3 which I regularly drive on NOA. Looks like a new glitch which Tesla will have to correct.
no, the car slowed down to "follow" the car in the adjacent lane - i was taking this picture while simultaneously pressing the accelerator to pass it, that is why it appears that the follow distance is so close. it was in fact keeping me at a distance from where it "thought" the car was positioned in my lane. kind of hard to explain, but the dark gray indicates that it does in fact want to follow that car, but should only be doing this if my car is in that lane.
 

5_+JqckQttqck

Active Member
Apr 27, 2018
1,851
1,407
Toronto
I believe it's linked to the AP computer thinking the car from the right is approaching from a merging lane and will slow down (stupidly) to match it's speed.

Pay attention next time you have NOA/EAP/AP engaged with a merge lane to your right. Even when the car/truck is way off - turning from the on ramp and the cameras see it... NOA/EAP/AP will slow down to match that car even though they're two lanes of space away and not parallel to your lane of travel.

I've submitted many bug reports on this. Lets hope FSD release fixes this. It is dangerous.
 
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Hello,

I’m having the same problem with my MS for quite a while.

I have come to the conclusion that only happens in certain roads with two or more lanes, so I think it’s an issue with the maps. Here in Europe passing cars on the left lane is not allowed, and my car behaves that way, but in some roads doesn’t want to pass the car on the right lane, which is annoying and dangerous.
 

mtndrew1

Active Member
May 12, 2015
1,501
4,410
Gardena, CA
I believe it's linked to the AP computer thinking the car from the right is approaching from a merging lane and will slow down (stupidly) to match it's speed.

Pay attention next time you have NOA/EAP/AP engaged with a merge lane to your right. Even when the car/truck is way off - turning from the on ramp and the cameras see it... NOA/EAP/AP will slow down to match that car even though they're two lanes of space away and not parallel to your lane of travel.

I've submitted many bug reports on this. Lets hope FSD release fixes this. It is dangerous.

This is exactly what it’s doing only the lanes aren’t on a path to merge.

FYI nobody listens to the bug reports, the report merely takes a snapshot of vehicle systems that service technicians can reference for later troubleshooting.
 
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Yeah mine has been doing this for a year, super annoying. We have HOV lanes and the car will slam on the brakes at every entry/exit break in the lines because of cars one or even two lanes over. There's a bug somewhere but Ranger said it's normal. I drive the HOV lane every day with my foot hovering the accelerator and spend lots of time with the "Cruise control will not brake" warning on the screen.
 

ecarfan

Well-Known Member
Moderator
Pay attention next time you have NOA/EAP/AP engaged with a merge lane to your right. Even when the car/truck is way off - turning from the on ramp and the cameras see it... NOA/EAP/AP will slow down to match that car even though they're two lanes of space away and not parallel to your lane of travel.
For several months now I have been impressed at how well my Teslas react to cars merging from onramps immediately to my right, adjusting speed so as to allow enough space for them to merge. It’s not perfect, but it’s pretty good, and that Auto Pilot capability didn’t even exist last year.

I have not seen the behavior you describe when cars are two lanes away from me.
 

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