How FSD behaves w/ Max Speed -- explained by Tesla software engineer

[Sjohnson20]

I don't have many problems with auto speed. It sometimes takes it awhile to get up to speed but I just did a road trip and it was doing 79 in a 70 and most of the time it was doing over the speed limit. It was doing about how I would do. Only thing was it reads the wrong signs which drops it down and then it has to get back up to speed again. I had to hit the pedal a couple of times since there were trucks coming from behind. Not sure if that's a mapping issue or an issue with the sign reading.

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[Sjohnson20]

You're going to have to get used to FSD choosing the speed, especially when the liability falls upon FSD and not you.

Until then, mark when it's not going fast enough with the voice notes. Remember to say what the speed limit is, the lane width, and what speed you expect it to go.

-Crissa

People are going to have to get used to being the passenger in self driving cars. The way I approach it is I am riding and someone else is driving, like in Uber. I don't pay attention to how fast the person is driving unless they are driving like a lunatic.

I make corrections if something goes wrong but I let it do it's thing. I just sit there and don't have to touch anything. It's way easier than driving 400 miles on the interstate myself.

 

[TiMan]

Senior staff software engineer at Tesla AI @philduan
explains how FSD handles max speed.

I took out a Model-X for a test drive on FSD. Exiting from a freeway, at about 50mph, where there was some construction with temporary barriers, the car tried to swerve to the left; into the concrete barriers. I had to make a quick correction to avoid collision. When I reported this to the sales people, the response that I got was, "The FSD is always learning." Needless to say, when I next took a drive in a cybertruck, I had the FSD turned off!

 

[Mdub]

Perhaps, but that is not reality today. FSD chooses speed poorly at least a few times per trip, and Tesla currently accepts 0 liability. I am not in a Cybercab without human controls, I am in a vehicle that should at least attempt to meet the parameters set by its user. If they intend for this to be the behavior, enable it when it works better.

Don't get me wrong, I enjoy using FSD, but not honoring the user set speed is a deficiency.

My understanding is FSD is AI and AI is configured from human input. So, FSD would normally go with the flow of traffic on busy highways. I would assume it has already learned this by now. But also agreed, user input should be considered by AI, and should I assume it already is?

I'm buying a CT and can't wait to try out the FSD.

 

[Pops]

My understanding is FSD is AI and AI is configured from human input. So, FSD would normally go with the flow of traffic on busy highways. I would assume it has already learned this by now. But also agreed, user input should be considered by AI, and should I assume it already is?

FSD is great, but the issue/behavior most users are referring to is this:

• You can set a speed with the right scroll wheel.
• FSD will not always immediately go to that speed, it can remain below it, even on an empty road.
• The DEV quoted is saying its by design, and setting a speed is "legacy cruise control".
• Pressing the accelerator will increase the speed, sometimes its temporary.
• FSD sets speed by reading speed limit signs AND/OR with a GPS database.
  • These speeds can be incorrect.

Overall I would call this a minor issue/annoyance. Its unfortunately that Tesla feels the users selected speed should not always be honored.

 

[aadams1278]

Perhaps, but that is not reality today. FSD chooses speed poorly at least a few times per trip, and Tesla currently accepts 0 liability. I am not in a Cybercab without human controls, I am in a vehicle that should at least attempt to meet the parameters set by its user. If they intend for this to be the behavior, enable it when it works better.

Don't get me wrong, I enjoy using FSD, but not honoring the user set speed is a deficiency.

You’re completely right. I live in a rural area where 55mph country roads are the norm. This isn’t endlessly winding roads that a motorcycle would struggle with, it’s normal wide open roads with curves. Yes, pressing the accelerator will speed up but as soon as the car wants to slow down it does it excessively and doesn’t resume the appropriate speed afterward. To everyone saying you can just use the accelerator if you want to go faster, yes you can, but the huge problem with that which nobody seems to be mentioning is that means FSD will not brake for you. A message comes on the screen saying accelerator pressed and FSD will not brake. If someone stops or slows suddenly in front of you or pulls out in front of you abruptly or a pedestrian gets too close, any reason the car would brake suddenly that you may not notice, is now prevented.

This combination of FSD driving too slow and the driver constantly pressing the accelerator makes the overall operation less safe.

As has been said, all input being error is a fantastic goal, but it isn’t today’s reality. Since it’s clear FSD hasn’t mastered auto speed selection, it SHOULD be taking that input from humans and refining its learning until then. Removing this ability for us to give it input is not good. The computers could be evaluating their opinion of best speed with the human input speed without forcing their speed on us. And before you say press the accelerator, that’s a less safe way to provide the input than setting a desired speed with the scroll wheel.

 

[smg]

This is just not realistic for highway driving.

There are 21 states with speed limits of 75mph, 8 states with speed limits of 80mph and of course we have 85mph in the very state where the CT itself is built!

If you're not going to give me FSD at 80-85mph without making me anxiously feather my speed for hours on end between below the flow of traffic and penalty shutoff, at least give me the option for TACC with lane centering and let me switch between those modes on the fly. My 3+ year old F-150 does this just fine.

Right now if I switch to TACC on the CT (which won't lane center) and want to go back to FSD I have to put the damn truck in park! Not convenient!

I can not for the life of me understand defending the current state of a developing technology when there is clearly so much more room for improvement.

 

[Zane Edwards]

Senior staff software engineer at Tesla AI @philduan
explains how FSD handles max speed.

Ok I get it but there should also be an option to do exactly what I want. Speed and style.

 

[mhaze]

I can have absolutely flawless drives aside from the speed. There are a few “25 means 25” roads in this area and FSD loves to scream down them at about 38-42 Mph.

Until they can fix that, I will be forced to disengage, slow down to the correct speed, and reengage each time

Yesterday I watched the FSD maintain the last 25mph speed sign it saw for about 20 miles down a Texas country road. Maybe the 55mph sign was obscured by a truck passing on the right, don't know. There's also the FSD's inability to figure school zone slowdowns, and it's needing my input due to my superior experience and superior human braininess. Like when he's a mile away from an intersection in rush hour and I KNOW THERE'S A FRICKING HALF MILES OF CARS in the turn lane ahead and I put the turn signal out.

then there's all the times he chastises me/us for looking left and right and all around. Hey, got some new for you - those big heavy things on the road that want to smash into you, they do not just come from the straight ahead viewport that FSD would train "inferior humans" on. They come from all over- both sides, the rear, a couple directions at once, and the front.

 

[mhaze]

That's basically a Texas problem. (and a few other states) 85 mph speed limits don't exist for the majority of US roads.

Wait, so you think a vehicle made in Texas should follow your other state rules and inconvenience those of us in Texas? I kind of think the car's AI could recognize this and adjust accordingly but until it has this ability, actual speed limits and actual driving speeds have to be the inputs for limits in the software.

 

[Stuck4ger]

I should clarify. I want to be able to use FSD but NOT have to have a destination plugged in nor have it change lanes and stuff. I want to steer but sometimes, sitting in traffic, I just want to be able to let the car keep distance.

I’ve driven it some with “minimize lane changes” and no nav destination. It works fine if there aren’t a bunch or intersections or forks in the road.

 

[Crissa]

Dumb question...

What are voice notes?

I have screamed, "you stupid fucking thing go faster!!" augmented by my clear shifting in a toddler temper tantrum disapproval in the seat.

I like to give both aural and visual clues.

Am I doing it right?

There's a button on the screen for leaving a note when FSD does something wrong.

Agree liability is key. Imagine your car approaches an intersection with green light right-of-way, with level 4 (future coming) fully functional FSD in control. At left crosswalk a ...

This is not a thing that can happen. FSD would stop as quickly as possible; if it could swerve to avoid the most pedestrians, it would. It's not complex. No humans make such weird 'full information' decisions, either.

Just throwing this out there… while in dad you can press the accelerator and speed up to you desired speed I. Case it’s going to slow and it will mostly maintain that speed… I’ve done it multiple times.

If you press on the accelerator you override automatic emergency braking, so always be aware when you do.

????

Liability falls on FSD?

In what world does that happen.

...

But, to your comment. I am not sure if the Liability will ever be transferred from the driver. Ever.

In the world in which the software is feature complete. If it doesn't transfer off you, then it's not level 3+ autonomy.

People are going to have to get used to being the passenger in self driving cars. The way I approach it is I am riding and someone else is driving, like in Uber. I don't pay attention to how fast the person is driving unless they are driving like a lunatic.

I make corrections if something goes wrong but I let it do it's thing. I just sit there and don't have to touch anything. It's way easier than driving 400 miles on the interstate myself.

Yes. You should approach it more like a teen who you know will make minor errors, and be ready to grab the wheel if it turns wrong. But a relaxed hand, otherwise, keeping a sharp eye out for signs it may miss (it cannot read arbitrary signs yet).

Ok I get it but there should also be an option to do exactly what I want. Speed and style.

There is. You drive the vehicle yourself.

-Crissa

 

[Nice2CTu]

This is not a thing that can happen. FSD would stop as quickly as possible; if it could swerve to avoid the most pedestrians, it would. It's not complex. No humans make such weird 'full information' decisions, either.

Take a look at this example, a pedestrian on right side of street falls into path of an oncoming Tesla, probably going about 40 mph.

https://www.instagram.com/aigleeson/reel/DBQ8EU9tcxG/

The FSD swerves immediately, avoiding the pedestrian and crashes head-on into an oncoming vehicle in the left oncoming lane. This is an example of a no-win situation, and I agree the Tesla made a split-second decision that a human would not. But here's the thing (for me anyway). Was the car crash safer? If there were 4 people in the car, would children in the back seat be hurt, was the driver hurt. You can see the airbags deploy, myguess is that Tesla car made an excellent decision here, but it could be a more severe outcome. This is a "thing that did happen" and we can't imagine or predict how many situations like this will occur. The pedestrian probably won't sue, but the head-on collision recipient in the other lane is completely not at fault. This is not a good example of who should pay for liability because it might be argued either way was best decision, especially if more people were permanently insured in a 4-passenger car than a single pedestrian being tripped by sidewalk walkers into an oncoming car. To me it is an interesting glimpse into the future of liability assumptions, and more so assuming we eventually all drive FSD with no control and overide.

 

[kingq]

Ideally, FSD should not be tuned per vehicle model, say CT/3/Y/S/X, but rather per driver. It should learn my driving habits when FSD is not on, and drive closely of my style when I turn on FSD, in terms of speed, trailing distance, lane changing, braking, etc. I think eventually it may act like this, but long way to go.

 

[MeadowShade]

There's a button on the screen for leaving a note when FSD does something wrong.


This is not a thing that can happen. FSD would stop as quickly as possible; if it could swerve to avoid the most pedestrians, it would. It's not complex. No humans make such weird 'full information' decisions, either.


If you press on the accelerator you override automatic emergency braking, so always be aware when you do.


In the world in which the software is feature complete. If it doesn't transfer off you, then it's not level 3+ autonomy.


Yes. You should approach it more like a teen who you know will make minor errors, and be ready to grab the wheel if it turns wrong. But a relaxed hand, otherwise, keeping a sharp eye out for signs it may miss (it cannot read arbitrary signs yet).


There is. You drive the vehicle yourself.

-Crissa

Do you have a Tesla?

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