# Autopilot Speed Limit



## francoisp (Sep 28, 2018)

From the Model 3 Owner's Guide, in the Speed Assist section (page 82):
"The speed limit is determined automatically based on detected traffic signs and GPS data. "

In my area around Cleveland (OH) I am finding that the speed limits showing by on the display are often incorrect. I've been paying attention and there are clearly visible traffic signs on many the roads with speed limit inaccuracies. I don't think Speed Assist reads the traffic signs because I would think that over time the inaccuracies would go away.

This brings me to a seconds point: I think it would be helpful to add one more choice to the "relative" and "absolute" options in the Autopilot Speed Limit menu. I'd like to have the option to set the speed based on the current speed of the car. This would be similar to a standard intelligent cruise control. I understand that Speed Assist tries to be helpful, however due to the number of inaccuracies it's forcing me to constantly adjust the speed down.

Any thoughts on this?


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## AZBMT (Oct 9, 2018)

Absolutely correct. I see it the same way. You're going 65 in a 65, then you engage AP. Since you have + 13 set in the limits, it jumps to 78... All I wanted was 65


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## Johnm6875 (Nov 14, 2016)

FrancoisP said:


> From the Model 3 Owner's Guide, in the Speed Assist section (page 82):
> "The speed limit is determined automatically based on detected traffic signs and GPS data. "
> 
> In my area around Cleveland (OH) I am finding that the speed limits showing by on the display are often incorrect. I've been paying attention and there are clearly visible traffic signs on many the roads with speed limit inaccuracies. I don't think Speed Assist reads the traffic signs because I would think that over time the inaccuracies would go away.
> ...


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## francoisp (Sep 28, 2018)

Johnm6875 said:


> I had hoped the newest update would give more accurate speed limits for my area (Auburn, CA) but the same incorrect limits are still there, even though the signs and limits haven't changed in years. Who do we notify?


I've asked the same question to Tesla Support and I was told there is no mechanism to report the inaccurate or missing speed limits. Hopefully Tesla will soon start using the speed limit signs as it states in the owner's manual. Yesterday I was driving in a 25 mph zone and the car was showing 55 mph!


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## RolfS (Oct 2, 2017)

AZBMT said:


> Absolutely correct. I see it the same way. You're going 65 in a 65, then you engage AP. Since you have + 13 set in the limits, it jumps to 78... All I wanted was 65


Set your offset to +0, then drive the speed you want to set it to, then set it and it will hold that speed. At least mine works that way.


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## jsmay311 (Oct 2, 2017)

RolfS said:


> Set your offset to +0, then drive the speed you want to set it to, then set it and it will hold that speed. At least mine works that way.


That workaround is okay if (A) the speed limit data is always right, which it isn't, and (B) you never want to go below the speed limit.


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## Love (Sep 13, 2017)

FrancoisP said:


> I've asked the same question to Tesla Support and I was told there is no mechanism to report the inaccurate or missing speed limits. Hopefully Tesla will soon start using the speed limit signs as it states in the owner's manual. Yesterday I was driving in a 25 mph zone and the car was showing 55 mph!


I just keep using the right scroll wheel "bug report" and saying what the correct speed limit is. Probably falls on deaf ears but makes me feel better about myself! 
There's a road near me that is 45mph and with the new maps, for WHATEVER reason, our cars now think it's 25. We drive this road EVERY day for about 2 miles each way to/from work, to/from anywhere in town so the tiny annoyance that it is is starting to build up over time.
They definitely need a way to report inaccurate speed limits if bug report is not the correct way.


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## RolfS (Oct 2, 2017)

jsmay311 said:


> That workaround is okay if (A) the speed limit data is always right, which it isn't, and (B) you never want to go below the speed limit.


True. If you want to go slower than the indicated speed limit you will have to use the right thumb switch to slow down after you set it. But if you go faster than the posted speed the setting will hold. Also just pushing on the posted speed sigh will set cruise speed to the indicated speed.


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## francoisp (Sep 28, 2018)

Tesla should simply give us the extra menu option so that whatever the speed of the car is, that becomes the set speed limit. That should be easy to implement and if people don't like it then they don't have to use it. To me this is an obvious omission, but I realize that Tesla engineers are smart, so I'd like to understand why they decided not to include it.


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## jsmay311 (Oct 2, 2017)

FrancoisP said:


> To me this is an obvious omission, but *I realize that Tesla engineers are smart*, so I'd like to understand why they decided not to include it.


I've asked myself this question so many times about so many different design decisions in the Model 3 that I'm now seriously doubting the premise. 

Honestly tho, in fairness to the engineers, I strongly suspect Elon is personally to blame for most of the things I don't like about my car. I'm totally serious about that.


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## kort677 (Sep 17, 2018)

FrancoisP said:


> Tesla should simply give us the extra menu option so that whatever the speed of the car is, that becomes the set speed limit. That should be easy to implement and if people don't like it then they don't have to use it. To me this is an obvious omission, but I realize that Tesla engineers are smart, so I'd like to understand why they decided not to include it.


you can already do that, set the offset to zero and the car when you engage the tacc/ap the car will go at that speed that you're traveling at


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## DR61 (Apr 10, 2016)

kort677 said:


> you can already do that, set the offset to zero and the car when you engage the tacc/ap the car will go at that speed that you're traveling at


Wrong: if you are going below what the car thinks is the speed limit, the car will accelerate to that limit if offset is zero. Also the car will not let you set a negative offset.


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## Whaukap (Jul 9, 2016)

When on AP set at the 55 speed limit, and headed into town the speed limit signs step down to 45 then 35 then 25. But the vehicle slows to 50 then 40 then 30...... I have it set to a 0 offset but I can’t figure out why it doesn’t slow to the posted speed limit...... Bueller??


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## ADK46 (Aug 4, 2018)

I think part of Tesla's design decisions involves their goal of Full Self-Driving. Eventually, the car will have to follow speed limits on its own. Sitting in cubicles in front of computer screens, it seems easy to implement the software now, in advance, so they have. That's their strategy. That's Musk's way.

But they are too dedicated to this strategy, IMHO. Tesla must know that the mapping data is not reliable enough, that _they'll_ be sending cars controlled by _their_ software down Main Street at 55 mph, hoping _we_ will catch the error. They must think that implementing the system anyway will somehow force rapid improvement. Someone within Tesla even told their tech writers that the car reads speed limit signs, hoping that this would speed that capability along.

Can you imagine buying a toaster that included instructions asserting that it would automatically detect different types of bread, when it does no such thing? A Tesla toaster would include the warning "Beta. It is the operator's responsibility to keep a close watch on their bread".

Tesla's customers will become more conventional over time - less of the forgiving early-adopter-fanboy type. Does your grandmother know what "beta" means? Tesla needs to manage this transition. Musk: "I hate to say this, but we have to become more mature as we manufacture cars for the masses. We're going to phase out "beta" stuff by the end of 2019."


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## francoisp (Sep 28, 2018)

Whaukap said:


> When on AP set at the 55 speed limit, and headed into town the speed limit signs step down to 45 then 35 then 25. But the vehicle slows to 50 then 40 then 30...... I have it set to a 0 offset but I can't figure out why it doesn't slow to the posted speed limit...... Bueller??


Based on my experience I do not believe the car uses posted speed limits: it probably uses a GPS-based database that contains obsolete or incorrect speed limits. What you described happens to me all the time.


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## kort677 (Sep 17, 2018)

when on many roads that are NOT limited access divided roads 
the AP will limit you to 5 MPH over the speed limit


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## Jay Jay (Oct 26, 2018)

This is an incredibly annoying flaw that they need to fix. I've talked with Tesla and reported it and the guy told me to keep filing bug reports when I'm in the car and it happens. So, I do. Everyone else should too.


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## kort677 (Sep 17, 2018)

Jay Jay said:


> This is an incredibly annoying flaw that they need to fix. I've talked with Tesla and reported it and the guy told me to keep filing bug reports when I'm in the car and it happens. So, I do. Everyone else should too.


repeat as needed, "it's only a beta"


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## Jay Jay (Oct 26, 2018)

What's your point kort? It's an issue in the beta, they need to fix it, and I'll report it every time it happens until they do.

Also, this isn't something that should be an issue even in the beta. Many GPS units and many phones are fully capable of knowing the speed limit of the road you're on. And I expect my Tesla alien technology machine to be able to do this most simple of things.


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## kort677 (Sep 17, 2018)

Jay Jay said:


> What's your point kort? It's an issue in the beta, they need to fix it, and I'll report it every time it happens until they do.


the point is that the technology is NOT perfected, wonky things can and will happen. 
just putting this out there "The *definition* *of* the word *insanity* could be doing the same thing and expecting a different result'


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## Jay Jay (Oct 26, 2018)

Just putting this out there: the squeaky wheel gets the grease.


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## ADK46 (Aug 4, 2018)

kort677 said:


> repeat as needed, "it's only a beta"


That's right. If we don't like it, we can always choose to use the prior, bug-free, production-quality, non-beta version of adaptive cruise control.

Where do we select that option?


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## kort677 (Sep 17, 2018)

ADK46 said:


> That's right. If we don't like it, we can always choose to use the prior, bug-free, production-quality, non-beta version of adaptive cruise control.
> 
> Where do we select that option?


tesla never had that option in any AP equipped car. if you want that I believe it is part of the NON ap cars


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## ADK46 (Aug 4, 2018)

kort677 said:


> tesla never had that option in any AP equipped car. if you want that I believe it is part of the NON ap cars


Just in case you missed it, I was criticizing Tesla for issuing a constant stream of beta software, never producing a stable version, so we don't have the choice. In other software products, you pay for a stable version. If you wish to help test a beta version, you don't pay for it. I get that Tesla is a trail breaking company, but this is at least a little goofy. It is definitely goofy that Tesla does not offer a stable version of adaptive cruise control, something that's been available in most cars for many years.


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## MelindaV (Apr 2, 2016)

we get it, you don't like Tesla's process.


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## kort677 (Sep 17, 2018)

ADK46 said:


> Just in case you missed it, I was criticizing Tesla for issuing a constant stream of beta software, never producing a stable version, so we don't have the choice. In other software products, you pay for a stable version. If you wish to help test a beta version, you don't pay for it. I get that Tesla is a trail breaking company, but this is at least a little goofy. It is definitely goofy that Tesla does not offer a stable version of adaptive cruise control, something that's been available in most cars for many years.


welcome to the world of tesla


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## francoisp (Sep 28, 2018)

DR61 said:


> Wrong: if you are going below what the car thinks is the speed limit, the car will accelerate to that limit if offset is zero. Also the car will not let you set a negative offset.


Just got version 44.1 installed a few minutes ago and I noticed that it is now possible to enter a negative offset of up to -20. I'll give it a try later to see if this works.


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## jsmay311 (Oct 2, 2017)

FrancoisP said:


> Just got version 44.1 installed a few minutes ago and I noticed that it is now possible to enter a negative offset of up to -20. I'll give it a try later to see if this works.


I just learned this, more than a month later.  Idk how many people are unaware of this change. Maybe it should get its own thread so more people see it.

Would've been nice if this was in the release notes.


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