Phantom Breaking Getting Worse?

[67King]

I don't know. The car darn sure reacts, violently at times, to stuff it shouldn't. The biggest issues I've faced lately are people turning left in front of me on divided highways with high speed limits. Plenty of clearance, but I'm going along with traffic, and a guy gets a break and goes across, the car slams on brakes. Last time, it started screaming (the beeping crash warning thing) at me, too. Dropped 10MPH or so and then just went right back to my set speed. I'm getting used to the TACC, but I'd really rather just have dumb cruise.

 

[Knightshade]

I don't know. The car darn sure reacts, violently at times, to stuff it shouldn't. The biggest issues I've faced lately are people turning left in front of me on divided highways with high speed limits. Plenty of clearance, but I'm going along with traffic, and a guy gets a break and goes across, the car slams on brakes. Last time, it started screaming (the beeping crash warning thing) at me, too. Dropped 10MPH or so and then just went right back to my set speed. I'm getting used to the TACC, but I'd really rather just have dumb cruise.

...if people are turning in front of you it's not a divided highway.

It is a place AP explicitly shouldn't be used though- it's not designed or intended, at all, for use with any place there could ever be either oncoming or cross-traffic.

Just need HW3 with 11x the power and an entirely new code base, and advanced neural nets and all these problems will be solved!

Seriously though, I’ve never experienced any significant phantom braking. Or breaking.

Same here.

The one guy that actually measured his "terrible phantom braking" and posted about it measured... 0.15g of decel.

Less than full regen provides with 0 use of the actual brake pedal.

I HAVE experienced that on highways especially around merges but there's nothing really phantom about that.

 

[AlanSubie4Life]

Same here.

The one guy that actually measured his "terrible phantom braking" and posted about it measured... 0.15g of decel.

Less than full regen provides with 0 use of the actual brake pedal.

I think it is a psychological effect, where uncommanded deceleration/acceleration is more noticeable and disturbing for some users than when they have the vehicle under full manual control. Or maybe my car is just a gem.

 

[AlanSubie4Life]

It is a place AP explicitly shouldn't be used though- it's not designed or intended, at all, for use with any place there could ever be either oncoming or cross-traffic.

I assumed he was just using TACC only. But arguably this is the desired behavior. It is prudent to slow down sometimes in these cases.

 

[AlanSubie4Life]

It is a place AP explicitly shouldn't be used though- it's not designed or intended, at all, for use with any place there could ever be either oncoming or cross-traffic.

I know this is one of your favorite topics , but I assumed he was just using TACC only. But arguably this is the desired behavior. It is prudent to slow down sometimes in these cases.

 

[Knightshade]

I know this is one of your favorite topics , but I assumed he was just using TACC only. But arguably this is the desired behavior. It is prudent to slow down sometimes in these cases.

totally possible- but doesn't change the fact the system doesn't understand cross traffic and isn't designed or intended to. (part of why the manual states not to use TACC on city streets)

TACC and AP both fundamentally assume all traffic is going the same direction you are.

When it gets input for which that isn't true behavior might be weird, so it shouldn't really be used in cases where it may get such input.

 

[AlanSubie4Life]

totally possible- but doesn't change the fact the system doesn't understand cross traffic and isn't designed or intended to. (part of why the manual states not to use TACC on city streets)

TACC and AP both fundamentally assume all traffic is going the same direction you are.

When it gets input for which that isn't true behavior might be weird, so it shouldn't really be used in cases where it may get such input.

I didn't realize that TACC was also limited to controlled-access situations. I don't keep track of the fine details of the manual I guess.

 

[Knightshade]

I didn't realize that TACC was also limited to controlled-access situations. I don't keep track of the fine details of the manual I guess.

well, wording is slightly different, but it says it's intended for use on dry straight highway, and among other things not to use on city streets, or anywhere with constantly changing traffic conditions, and don't trust it around pedestrians or bike either.

 

[UCIBtheG]

I meant to add this to my lane change complaint... In Autopilot, why oh why does the M3 sometimes initially SLOW DOWN by a few mph when I hit the turn signal to change lanes? No one in the lane I'm headed for but there is someone right behind me. Sometimes the slowdown triggers them to go around me just as I'm trying to go around the car ahead. And in these cases I try to avoid eye contact since I know I'm getting yelled at.

Have had this happen many times and wholeheartedly agree that it seems like it should be fixed by now. There is nobody ahead of me, nobody near me in the slower lane I intend to move over to, yet it drops several mph, usually with someone behind me as mentioned. Really aggravating for them and embarrassing for me when it happens (which, to be fair, isn't all the time).

I've had my fair share of phantom braking events, usually when approaching overpasses with deep shadows or overhead signs spanning the width of the freeway. I really worried about the possibility of getting rear-ended, but I've noticed that every time it has happened nobody is anywhere near behind me. The car can clearly detect another car approaching from behind, as it will prompt me to move over when using NoA. With as common as phantom braking seems to be, I'd have expected to hear about one leading to a rear-ending on this forum, but I can't recall one.

 

[67King]

...if people are turning in front of you it's not a divided highway.

It is a place AP explicitly shouldn't be used though- it's not designed or intended, at all, for use with any place there could ever be either oncoming or cross-traffic.

Yes, it is. It is not a controlled access (with exits) highway. It is a divided highway with medians, but non controlled roads. Parts of it are 45, parts are 55. These kinds of highways are very, very common.

And I'm just using cruise control, not AP. TACC is Traffic Aware Cruise Control. And it brake checks. And if you think that it explicity should not be used there, then I am talking to a wall. Tesla will actually let me use AP gonig 70 through there, probably more, but the limit is 55, so I don't.

 

[67King]

I assumed he was just using TACC only. But arguably this is the desired behavior. It is prudent to slow down sometimes in these cases.

No, it is dangerous. Morning commute traffic, people bunch up. You can argue they shouldn't, you can aruge they should go 55, because that is the speed limit. But that is completely and totally detached from reality. People bunch up. It isn't letting off the throttle as a similar ICE car would to slow down a little, it is slowing down very abruptly. 10MPH in under a second. Travelling at 100fps at that speed, and people 1.5 car lengths behind me. NHTSA uses 1.5 seconds for average reaction time. That is going to suck up half of that thirty feet before they react. Get 2-3 cars bunched up, and a few cars back, someone gets rear ended. People have posted videos of accidents behind them from this, the one of the truck jack knifing being the most prominent.

 

[AlanSubie4Life]

No, it is dangerous. Morning commute traffic, people bunch up. You can argue they shouldn't, you can aruge they should go 55, because that is the speed limit. But that is completely and totally detached from reality. People bunch up. It isn't letting off the throttle as a similar ICE car would to slow down a little, it is slowing down very abruptly. 10MPH in under a second. Travelling at 100fps at that speed, and people 1.5 car lengths behind me. NHTSA uses 1.5 seconds for average reaction time. That is going to suck up half of that thirty feet before they react. Get 2-3 cars bunched up, and a few cars back, someone gets rear ended. People have posted videos of accidents behind them from this, the one of the truck jack knifing being the most prominent.

That's life. If someone is traveling too closely behind, it is time to disengage Autopilot, and dramatically increase following distance from whatever is in front, and pay extra special attention to possible obstacles. It sucks, but it's life.

I do wish that Autopilot would modify its behavior based on the vehicle behind the car (specifically its proximity). Sadly I suspect the hardware is not capable of this, even with advanced image depth mapping with monocular vision.

 

[67King]

totally possible- but doesn't change the fact the system doesn't understand cross traffic and isn't designed or intended to. (part of why the manual states not to use TACC on city streets)

TACC and AP both fundamentally assume all traffic is going the same direction you are.

When it gets input for which that isn't true behavior might be weird, so it shouldn't really be used in cases where it may get such input.

Then the cars should be recalled. It knows the speed limits, it knows where the streets are, it limits the speed of AP depending on the type of streets, and it has no problem engaging the driver aids.

Or I would just prefer to have a dumb cruise control that I can use like other dumb humans who just want to avoid getting a ticket. It is asinine to think that a cruise control shouldn't be used anywhere other than empty interstate highways. It is bad enough that it brakes hard on curves on two lane highways (which are not city streets, and are empty). That's really worse, as I drive down those going to my lakehouse all of the time, and I use cruise because it is too easy to get a ticket, and the sheriff's office does patrol those roads for speeders.

 

[67King]

That's life. If someone is traveling too closely behind, it is time to disengage Autopilot, and dramatically increase following distance from whatever is in front, and pay extra special attention to possible obstacles. It sucks, but it's life.

I do wish that Autopilot would modify its behavior based on the vehicle behind the car (specifically its proximity). Sadly I suspect the hardware is not capable of this, even with advanced image depth mapping with monocular vision.

Again, left turn at a crossroad on a divided highway. And again TACC, not AP. I am not following cars turning left hundreds of feet in front of me, so I can't increase the following distance. And I'm just trying to use cruise control the same way I've done it for 30 years.

THis whole notion of it being "safe" to slow down under any questionable condition is seriously misguided. It is like the darn fools that can't merge with 70MPH traffic because they are going 45, and think that slowing down even more will make it better. "Fast" isn't dangerous, it is speed differential that is dangerous. And since you track your car, you also know full well smooth is better than abrupt.

 

[Knightshade]

And I'm just using cruise control, not AP. TACC is Traffic Aware Cruise Control. And it brake checks. And if you think that it explicity should not be used there, then I am talking to a wall.

Or you should read the manual.

Where it points out not to use it in places with variable traffic conditions- like say a car moving across your lane in an entirely different direction than expected for example that the car literally is not meant to understand or deal with

Tesla will actually let me use AP gonig 70 through there

Tesla will also "let" you drive a car off a bridge into a river. Doesn't mean it's something the car is intended to do though.

Then the cars should be recalled. It knows the speed limits, it knows where the streets are, it limits the speed of AP depending on the type of streets, and it has no problem engaging the driver aids.

See above.

The fundamental assumption of TACC and AP/EAP is everyone is going the same direction on a road without intersections

If you want to keep using the system someplace it's not even slightly intended to work that's your call- but you don't get to then be mad it "doesn't work right"

it's working exactly as intended.

When you have TACC on going 55 and someone turns in front of you, and the car detects it- since the car doesn't understand intersections, it has to assume there's suddenly a car IN YOUR LANE RIGHT NOW AND IT IS NOT MOVING FORWARD AWAY FROM YOU AT ALL. So...brakes.

Otherwise you're asking it keep doing 55 in a situation the sensors tell it means you will slam into another car at 55 mph.


These are situations FSD (once the city driving bit gets rolled out) will handle. But the current system explicitly does not and is not intended to handle

Or I would just prefer to have a dumb cruise control that I can use like other dumb humans who just want to avoid getting a ticket.

Which, coincidentally, is a system that will let you slam right into another car at 55 mph!

 

[Knightshade]

"Fast" isn't dangerous, it is speed differential that is dangerous..

The irony here of course is you're getting mad at the car for braking when it thinks there's a 55 mph speed differential between you and the car it looks (to the system) like you're going to be slamming into shortly.