New problem with autopilot in v 2019.20.4.2 (video attached)

[raygduncan]

I have a 2018 Model 3, LR/AWD, recently updated to 2019.20.4.2. I drive the same 150 mile round trip each weekend on Interstate 10 from Westside to San Bernardino area. Since the update I have noticed 2 new problems.

First, the car "hunts" quite a bit when rounding a freeway curve at 70-75 mph, wobbling from one side of the lane to the other and sometimes even hitting the bumps on the line dividers -- this seems to be new or at least a lot worse than before on the same stretch of road. It also skirts close enough to concrete dividers on the left in construction areas that it makes me uncomfortable -- in areas where a human driver would tend to drift toward the right lane markings to stay away from the dividers, the car seems to like to stay in the left side of the lane.

Second, after I prompt a lane change, the car does not brake (or even slow down) appropriately while completing a lane change if a car slips into the same lane just in front of us at a lower speed. The first time this happened I thought the car would notice and react, and almost did not intervene in time, closing to within probably a foot of the other car. That was fairly scary. The second time this happened, I was alert to it and as soon as I saw the car was not slowing to match the one that popped in front of me, I hit the brake to disengage autopilot. You can see this at 0:38-0.46 in the attached video although it's not so dramatic there because you can't tell that I had to intervene. I don't remember this being an issue before. It's too bad Tesla doesn't put some data overlay on these photos to show the proximity sensors and autopilot status among other things.

On the good side, handling of lane splits and lane merges seems to be quite a bit better in 2019.20.4.2. There's a particular point on this route where a lane split and the car used to hunt back and forth and then pick a lane quite abruptly, it was quite disconcerting. Now it just glides smoothly into the rightmost of the 2 lanes after the split.

 

[Silicon Desert]

Hmmmm, maybe I am missing something. I did not notice that "hunt" thing you are talking about, and I did not see a place where you came within one foot of the car that slipped in on the right. Judging by the lane markers that was more like 7-8 feet. That's still too close for my comfort though. Are you talking about other situations not shown?

 

[muleferg]

I don't see anything either.

 

[ecarfan]

Ray I cannot see the behavior you describe in that video. Looks like flawless AP performance to me. I am not questioning what you describe as your perception of how the car was driving, just saying I can’t see it in the video.

I did observe that when the car changed lanes to move into your lane from the lane to your right, your car did not start to slow until the car was halfway into your lane. I see this all the time, but I don’t think it is necessarily dangerous. TACC can react much more quickly than you can to slowing cars ahead of you. What might appear dangerous to you may not be in terms of the “reaction time” of the Tesla computer driving your car.

 

[comraddan]

Ray I cannot see the behavior you describe in that video. Looks like flawless AP performance to me. I am not questioning what you describe as your perception of how the car was driving, just saying I can’t see it in the video.

I did observe that when the car changed lanes to move into your lane from the lane to your right, your car did not start to slow until the car was halfway into your lane. I see this all the time, but I don’t think it is necessarily dangerous. TACC can react much more quickly than you can to slowing cars ahead of you. What might appear dangerous to you may not be in terms of the “reaction time” of the Tesla computer driving your car.

I believe what OP was saying was that his Tesla didn’t slow down when the other car entered the lane in front of him - he manually hit the brakes and that’s why his car slowed down in the video.

 

[raygduncan]

Hmmmm, maybe I am missing something. I did not notice that "hunt" thing you are talking about, and I did not see a place where you came within one foot of the car that slipped in on the right. Judging by the lane markers that was more like 7-8 feet. That's still too close for my comfort though. Are you talking about other situations not shown?

Yes, as described in my caption, the scary incident with the car merging from the right was a previous incident where I almost did not intervene in time. The one on this video was as you say, probably 7 or 8 feet, however Autopilot did not recognize the car as being there (apparently) and did not slow to match speed immediately so I had to step on the brake pedal to disengage it, even though the car merging in was quite a bit closer than AP normally follows other cars when AP turned on.

As for the lane hunting and hugging the concrete divider, I have seen plenty of examples of that (I will save videos of that on my next round trip to San Bernardino and post them here) but they are not shown in this video.

 

[raygduncan]

I believe what OP was saying was that his Tesla didn’t slow down when the other car entered the lane in front of him - he manually hit the brakes and that’s why his car slowed down in the video.

correct

 

[justsomeguy]

Yes, as described in my caption, the scary incident with the car merging from the right was a previous incident where I almost did not intervene in time. The one on this video was as you say, probably 7 or 8 feet, however Autopilot did not recognize the car as being there (apparently) and did not slow to match speed immediately so I had to step on the brake pedal to disengage it, even though the car merging in was quite a bit closer than AP normally follows other cars when AP turned on.

As for the lane hunting and hugging the concrete divider, I have seen plenty of examples of that (I will save videos of that on my next round trip to San Bernardino and post them here) but they are not shown in this video.

I noticed the same behavior this morning with the merging car, but in my case it was actually exactly how I would have reacted in the situation as my car was following with quite a large gap prior to the merge. In the past it would have braked hard to slow down.

 

[My IOT]

I have a 2018 Model 3, LR/AWD, recently updated to 2019.20.4.2. I drive the same 150 mile round trip each weekend on Interstate 10 from Westside to San Bernardino area. Since the update I have noticed 2 new problems.

First, the car "hunts" quite a bit when rounding a freeway curve at 70-75 mph, wobbling from one side of the lane to the other and sometimes even hitting the bumps on the line dividers -- this seems to be new or at least a lot worse than before on the same stretch of road. It also skirts close enough to concrete dividers on the left in construction areas that it makes me uncomfortable -- in areas where a human driver would tend to drift toward the right lane markings to stay away from the dividers, the car seems to like to stay in the left side of the lane.

Second, after I prompt a lane change, the car does not brake (or even slow down) appropriately while completing a lane change if a car slips into the same lane just in front of us at a lower speed. The first time this happened I thought the car would notice and react, and almost did not intervene in time, closing to within probably a foot of the other car. That was fairly scary. The second time this happened, I was alert to it and as soon as I saw the car was not slowing to match the one that popped in front of me, I hit the brake to disengage autopilot. You can see this at 0:38-0.46 in the attached video although it's not so dramatic there because you can't tell that I had to intervene. I don't remember this being an issue before. It's too bad Tesla doesn't put some data overlay on these photos to show the proximity sensors and autopilot status among other things.

On the good side, handling of lane splits and lane merges seems to be quite a bit better in 2019.20.4.2. There's a particular point on this route where a lane split and the car used to hunt back and forth and then pick a lane quite abruptly, it was quite disconcerting. Now it just glides smoothly into the rightmost of the 2 lanes after the split.

My MS had an update last week. Before the update, the AP was very solid in the lane.
Immediately after the update, I started experiencing exactly what you described. It is so bad, that I am concerned that I could be pulled over for drunk driving. I’ve had to jump out of AP several times since then. I also have a regular commute, so I know exactly how the car should react at each turn.

I REALLY like the fact that Tesla updates over the air. I brag on regularly about how many improvements have been made since I purchased my MS Oct 2017.
However, I no longer feel safe in AP, at least not like I did before the update.