Forums

Overpass shadow artifact causing braking while in Autopilot

Overpass shadow artifact causing braking while in Autopilot

On a couple of occasions, typically on bright, sunny days while driving on Autopilot on the interestate, I've passed underneath an overpass and found that the Tesla autopilot system misinterprets the dark shadow cast onto the highway by the overpass and immediately initiates a braking maneuver, slowing the car by about 10-20 mph, and disengaging the autopilot.

When this has happened, it has typically been in relatively light traffic, but I am concerned that if it happened in a heavy traffic situation it could easily initiate a rear end collision. After all, following traffic would not expect for you to put on the brakes when you're driving 70-80 mph just because you're driving under an overpass.

I'm sure I'm not the first person to notice this. I'm curious to learn how other people deal with this situation and what steps Tesla is taking to address it.

jmccpa | April 23, 2020

I have experienced same.

Bighorn | April 23, 2020

Pretty common observation in the past. It should improve with neural net learning based on interventions. Need to be ready to accelerate through it.

Patronus | April 23, 2020

Yup, it is called "phantom braking" and it is pretty common with recent updates, sadly. I now drive with my foot hovered above the accelerator for the purpose of quickly recovering and not getting rear-ended.

vmulla | April 23, 2020

"slowing the car by about 10-20 mph, and disengaging the autopilot" @Windsurfer

--
I've experienced phantom braking in the past, and FWIW I have not seen that happen in the last few months. However, I don't remember AP getting disengaged; I just remember seeing a message to take over immediately.

Joshan | April 23, 2020

@vmulla +1 same behavior I get.

Would also add Phantom Braking for me does not drop it by 10-20 mph. It only last a second and is only a few mph, The ones that drop it by 10-20 mph are map errors and not phantom braking as you can see the max speed setting drop. At least for me...

TeslaTap.com | April 23, 2020

I doubt it's the shadow, and more likely the overpass being picked up by the radar as a huge item in the road. The radar sees the overpass as a huge reflection. AP has to decide if visuals should override radar or not. The shadow may make this harder. It has gotten better over time. A few places where I've had that occur 2 years ago never occur now.

M3phan | April 23, 2020

I’ve never experienced overpass shadow phantom braking, just two or three phantom braking events on the freeway in my first month or two of ownership in 2018, but have not had it since. Thankful.
Be sure to file a bug report when that happens to help with the data mining.

LostInTx | April 23, 2020

Have experienced 8-10 occurrences where an approaching overpass has caused a quick deceleration. The most repeatable is when the road slopes downward toward an overpass. My guess is that the cameras/sensors see the overpass at pretty much the same level as the car. The 3 doesn't know it's about to go on a downward slope.

howard | April 23, 2020

Same experiences in the past. I don't use AP or TACC at all. Not worth the risk regardless of how remote. I don't find it very relaxing being prepared to take over. It just makes no sense when FSD was to be here last year, now by year-end. Long ways to go. Be safe out there.

lbowroom | April 23, 2020

Yes, we all agree it can happen. Regen braking isn't going to cause you to get rear ended. It's no more abrupt than humans braking on highway overpasses like so many people do. The best mitigation is your right foot coming up to engage the throttle. You are paying attention, right? FSD is not released, AP is a driving aid. You have complete control of what the vehicle does.

howard | April 23, 2020

lbowroom

Sorry, but your right foot coming up to engage the throttle when it happens is too long a delay and then often results in an overreaction causing the car to over accelerate. I know as my wife would exclaim what the heck. She absolutely does not let me use it even if I wanted to. You know play the prototype tester. But hey you can make it sound like it is a very easy and smooth procedure all you want. Wait, maybe your just that fast and good at it. Practice maybe? No, just a silly deflection and not a good one at that.

lbowroom | April 23, 2020

Silly deflection that the driver is control of the car?

If that was true there would be many reported accidents but what the evidence shows is that AP is involved in fewer accidents per hours driven than no AP.

May concerns expressed here about potential rear ending, not one claim of it actually happening.

You keep demanding perfection. Perfection is it's not necessary for effective use

Does this sound like crazy talk to you, Howard?

lbowroom | April 23, 2020

So lets pretend you are using dumb cruise on a Tesla, or any other car for that matter. A car cuts in front of you traveling at a slower rate. Is it unreasonable to expect the driver to tap the brake with his foot before impact? how is this different?

FISHEV | April 23, 2020

It always did that but it has become more frequent since the 20,8.3.

edhchoe | April 23, 2020

It is true that no accident has been reported due to phantom braking. But it may piss off the driver behind you. If a road rage happens blame the phantom braking.

daddy88 | April 23, 2020

My latest experience 2 months ago was on a clear day with no overpass shadow and no cars in front.

More concerned about the car behind thinking he's being brake checked and turns into road rage.

ATJ | April 23, 2020

Happened to me today. Fortunately, there wasn't a car close behind me.

LostInTx | April 24, 2020

Agree with howard - it's idealist corporate-speak to go on about "you have to be in control when using EAP". Yea, no kidding - we've all read the silly manual.

The point is that occasional dangerous behavior by the car isn't always mitigated by "take over". It takes a second, literally a second, which means any car behind you has to respond, as does any potential car behind the car behind you.

Using EAP comes with beta related risks - we all know that. The known phenomenon relating to approaching overpasses will hopefully lessen over time and eventually disappear.

Until then, it's OK to say "man, this sucks!" while dealing with occasional sloshed coffee or earning a well-deserved finger from the guy behind you.

FISHEV | April 24, 2020

edhchoe | April 23, 2020 "It is true that no accident has been reported due to phantom braking. But it may piss off the driver behind you. If a road rage happens blame the phantom braking."

Was watching a Model 3 block traffic on I5 in Seattle yesterday. Sitting in far right lane (out of four), not passing the truck in the adjacent lane and pissing people off. Lifted in pickup in back of him so I'm guess road rage on the part of the Tesla driver.

Finally after making his "point" he speeds up and a big brake light display, no doubt when he took his foot off the accelerator and regen kicked in, he ends up flashing his brakes four times before getting over. The line up of people in back no doubt took it as his giving them the "light finger". Doubt he knew he was doing it as you can't really see the brake light indicator on the tiny graphic.

FISHEV | April 24, 2020

Got the Overpass Brake effect about four times on the ride into Seattle in the AM. None in the PM. Definitely has to do with how the lights hit the overhead structures. I get it on bridges with overhead structure also.

Pepperidge | April 24, 2020

There are two fatal cases of smashing into road crossing 18 wheeler. Tesla vision is still not able to distinguish overpass and road crossing 18 wheeler after 3 years and talking about robo taxi?

lbowroom | April 24, 2020

So what you're saying fish is that by adhering to federal regulations on brake light activation based on deceleration, Tesla is causing the murder of it's drivers from road rage.

If the driver doesn't want the car to decelerate under regen, the driver shouldn't abruptly lift completely off the throttle. The human body can feel deceleration.

And if we all know that the car occasionally slows at overpasses, or the specific overpass you drive under every day, why wouldn't you be prepared for that? You can see the overpass as you approach. Are you just getting a thrill pointing it out every time it happens and cursing Tesla?

Lonestar10_1999 | April 24, 2020

The R&D Engineers and Scientists at Tesla would have no clue or understanding of Autopilot without the steadfast help of FishEV and his unbiased documentation of real world Autopilot performance. We all owe a debt of gratitude to FishEV.

APRIL FOOLS

FISHEV | April 24, 2020

That was far LEFT lane above where Tesla driver was deliberately blocking traffic and then flashed his brakes four times when he finally got over.

Relative to this topic with the braking for overpasses having a potential for causing accidents, since it is unexpected braking, the point was that drivers in back seeing the unexplained braking might think it was directed at them and it could provoke a road rage incident.

lbowroom | April 24, 2020

News flash, not all Tesla drivers are nice guys. Flashing the brakes 4 times is a clear indication that it was deliberate and intentional. Lifting off the throttle does not cause the lights to flash.

When you drive with regen on, you don't lift completely off the throttle unless you are intending to slow down, therefore the federally mandated brake light actuation based on deceleration is completely appropriate. Without it, there is actually a danger of rear ending the car that is slowing down. The drivers involved are causing the road rage incident, not the car.

FISHEV | April 24, 2020

lbowroom | April 24, 2020 News flash, not all Tesla drivers are nice guys."

Tesla forum is certainly proof of that.

"Flashing the brakes 4 times is a clear indication that it was deliberate and intentional"

Not sure it was. Once when he got off cruise, then three times as he sped up and then deceled enough to trigger brakes, likely unknown to him. He created a situation where he needed to slow down.

Point was that because of his blocking the far left lane so long, those behind him no doubt took it as his being ever ruder with the blake flashes. Same for the phanton braking for overpasses being interpreted that way.

lbowroom | April 24, 2020

"He created a situation where he needed to slow down."

Yes, and since he needed to slow down, the brakes must flash as federally mandated.

lbowroom | April 24, 2020

sorry, not flash, brake lights must activate

Orthopod | April 24, 2020

It’s cool,

Now you don’t have to look at the road for other obstacles,
You have to look for the things that AP would define as obstacle in its algorithm

howard | April 24, 2020

Orthopod
You have to look for the things that AP would define as obstacle in its algorithm

More than just “look”. Constant scanning, anticipate, be prepared to take over in a split second, but not to the point of overreacting. But that’s the fun of beta development if you are a developer. Oh, that’s us. I guess for some they are so good at it, it is never an issue.

FISHEV | April 24, 2020

Ford does not call Lane Keeping or Dynamic Cruise "Beta" on the Mach-E or any of i's cars. Same for Toyota, GM, VW and others/

WW_spb | April 24, 2020

Mach E will not be produced any time soon now. You can wave a good bye to your wet dream

jallred | April 24, 2020

Someone knows very little about the software development lifecycle. What follows beta is a production release and there is zero chance that the Mach-E has a production release already.

The only way you may be right is that the Mach-E software probably hasn't reached Beta yet. Any of the car's software.

You may not like that the software is in Beta, but it is at least honest. The thing is that all of the other companies have a much shorter feature list... so it is easier for them to declare it feature complete.

For Tesla, defining it as beta is more about where they are headed then where they are at.

howard | April 24, 2020

jallred, For Tesla, defining it as beta is more about where they are headed then where they are at.

“Beta” is a legal release of liability. Nothing more nothing less. Tesla will never, ever be anything other than Beta regardless of whether the feature set is complete or not.

howard | April 24, 2020

jallred, For Tesla, defining it as beta is more about where they are headed then where they are at.

“Beta” is a legal release of liability. Nothing more nothing less. Tesla will never, ever be anything other than Beta regardless of whether the feature set is complete or not.

FISHED | April 24, 2020

You are very pessimistic for someone that doesn't even use the feature.

lbowroom | April 24, 2020

Howard has no problem criticizing and judging my posts, won’t say a single thing about fish’s.

howard | April 24, 2020

Actually I have had no reason nor the opportunity to use it until earlier today on the 40 minute drive to DIA. Traffic needless to say was very light but I was pleasantly surprised that for the first time using AP the car stayed centered to the inside drive lane when approaching off and on ramps. I made a couple of instigated lane changes and that went fairly well. Real progress I must admit. Traffic was too light to get a real feel for any TACC improvements. I be making a number of airport trips in the next few weeks so I’ll try it a bit more. It will be a while before I find it remotely relaxing but......

howard | April 24, 2020

Inside would be the slow lane closest to the on/off ramps.

jallred | April 24, 2020

Use of word "beta" is explicitly so that drivers don't get comfortable. It is not beta software in the standard sense.

jallred | April 24, 2020

No way it magically counts as a release of liability.

srihari | April 24, 2020

"A Beta phase generally begins when the software is feature complete but likely to contain a number of known or unknown bugs" - Wikipedia. Of course, it is Beta software.

Lonestar10_1999 | April 25, 2020

It stands to reason that manufacturers designing leading edge software without using “beta” designation would be less likely to make changes to their product even if there are serious flaws. Let FishEV be the guinea pig for the Mach-E.

lbowroom | April 25, 2020

If he does “get one” he’ll be telling the world why they shouldn’t. Just like he has here for the last 4 years.

fzeller | April 25, 2020

I observe phantom braking frequently, especially in the tunnels. Seems to happen more and more with release 2020.X

teslamazing | April 25, 2020

Again, lots of “glad there wasn’t anyone behind me”

Ppl are saying this is common. If that’s the case, why hasn’t there been any accidents with phantom braking behind the main culprit?

Because the Tesla knows. If there were to be a car, it woulda adjusted accordingly preventing an accident.

FISHEV | April 25, 2020

@howard | April 24, 2020 “Beta” is a legal release of liability. Nothing more nothing less. Tesla will never, ever be anything other than Beta regardless of whether the feature set is complete or not."

Fair to say by performance comparison to Ford, Toyota, Audi et al Tesla's adaptive cruise is definitely "Beta" from the phantom braking to the unexpected accle/decel based on map data.

WW_spb | April 25, 2020

Safe to say anything Fish says is not true

Joho.keith | April 25, 2020

I’ve noticed the unexpected braking is much more common on empty highways. It seems that in the absence of other cars, FSD gets fooled by shadows and other things. I was able to replicate the overpass shadow braking on an empty highway but it also brakes on a totally empty road with no obvious shadow or other issue.

Joho.keith | April 25, 2020

I’ve been also logging bug reports immediately after the unexpected braking. Hopefully they will be able to see what’s going on. I suspect the neural net training was primarily done in high traffic so empty roads are likely very underrepresented in the training set.

Pages