Autopilot restriction on highway

Autopilot restriction on highway

I updated to v8.0 (2.50.114) last night and made a drive I have made many times today on a major divided highway (I-29 in North West Missouri) with 70 mph speed limit. While cruising at 70 using autopilot I suddenly get an alert saying that autopilot is restricted to 50 mph and the car immediately starts slowing down, causing some consternation to me and drivers behind me. I turn off autopilot and after about 1 mile I try autopilot again and it goes back to 70 mph. The same thing happened at the same place on the highway on the return segment. This was not a nag, or a place hands on steering wheel alert, it was the autopilot speed restriction kicking in for no apparent reason.

Is this some kind of "learning" behavior? If so, it is an error (Type I).
Does GPS cause it to think I am on the parallel access road? Whatever it was, it had never happened before and I have driven this boring stretch of highway many times (unfortunately).

burdogg | 25/12/2016

UBQP - something right at that spot must make the car think the speed limit is 50. Since it happened at the exact same spot, hard to say it was a "malfunction" as far as just needs a reboot, or thought it saw a speed limit. Maybe old GPS or something makes it think the speed limit is 50 right there. That is just bizarre though. Be interesting to see if it does it every time you drive that spot :)

kevin | 25/12/2016

What does the speed limit sign on the Instrument Cluster show? 50 or 70?

By the way, you don't have to turn off AP to go faster. Just press the accelerator.

kevin | 25/12/2016

This might be a good instance to use the "REPORT" voice command so that Tesla gets a snapshot of what's happening.

TesMD | 25/12/2016

This exact scenario happened to me the other day on a the 91 west bound toll lane in S. Cali and I did start a thread on it voicing my concern as I almost got rear ended. Unfortunately, not many people read the thread/responded to it. This is a huge safety issue.

miyamky | 25/12/2016

That happens also when the system is confused by your environment.

UBQP | 25/12/2016

I did not notice what the speed limit showed on the instrument cluster, but will pay attention next time. I did get a tad confused with it slowing down rather abruptly and spent time disengaging the AP when I should have just pressed the accelerator.

Perhaps the system was confused by the environment. It was a little foggy out and at first I thought the AP was responding to the fog and slowing down from 70 to 50 as a safety measure, but it sure wasn't THAT foggy out. I could easily see a couple hundred yards or more ahead, but maybe the windshield got dirty + fog confused the camera? Don't know, but nothing like this had ever happened before the update.

I have not used the REPORT voice command, so will keep that in mind as well.

Thanks for the responses.

bruntonma | 25/12/2016

This is another buggy update from Tesla. Apparently they do little or no testing before sending these things out. I had the same thing happen to me yesterday on highway 52 in SC between Goose Creek and Moncks Corner. Car has always recognized it as a divided road where AP speed restriction does not apply. Suddenly, for no reason, the car starts to decelerate to 50 mph from 69. Couple hundred yards later, the speed setting changed back to 69.
This sort of sloppy programming is going to cause accidents, which will get Tesla sued out the wazoo.
I'm headed from SC to NJ tomorrow, and am approaching that trip with more trepidation than I have in past trips.

UBQP | 25/12/2016

Hopefully Tesla will pay attention to the feedback of us beta AP testers and make necessary corrections, perhaps with 8.1 next week. I think I have counted 4 reports of this behavior so far in this and the TMC forum.

bbugbee | 25/12/2016

There is a fundamental problem with Tesla restricting the AP to the posted speed that nobody, I mean nobody drives.

First, it’s a safety issue, but not the one Tesla claims. Posted speed limits on so-called restricted and highways roadways are by designed historically set below the driving capacity or engineering specs of the roads’ design. Restricting the driver to speed at that is 9 out 10 times “below” the flow traffic either makes the AP feature (which we all paid extra for useless, or at greatly minimum reduces the functionality of driving in AP mode which includes the adaptive cruise control safety feature.

Second, Tesla’s elimination of the 5 mph+ posted speed buffer allowance (which was already too restrictive) to be clear, is Tesla’s move to dumb down the technology that is neither a safety issue nor an engineering issue, but Tesla lawyers dictating policy. Something you’d expect from Detroit or Toyota, but not Tesla, which built its reputation on innovation.

Finally, I don’t know about the rest of you who may be happy with the new 8.1 driving restriction, but I think we’re all due a refund from Telsa for unnecessarily restricting an optional and highly functional feature many of us purchased!

malcolm.hall1932 | 26/12/2016

bbugbee: "I don't know about the rest of you but ....................................... ".
Tell that to the dozens of idiots that abused AP1 and forced Tesla's hand.
You can count me as a no.
On the other hand you could support Tesla's efforts to solve the problem with AP2.

martin | 26/12/2016

I see the same behaviour occasionally when there is no explicit speed limit sign. Something in the navigation database must tell AP a wrong speed limit. Just use your right foot to adjust...

david | 26/12/2016

My prediction is that before FSD is turned on, AP 2 will not allow any driving above the posted speed limit anywhere, including the highway. They have really turned to the dark side and ruined a useful feature and major selling point of the car. I am so glad we stopped "upgrading" at FW 7.1. So sorry for everyone now suffering under the heavy hand of tesla lawyers.

joegazin | 26/12/2016

I just took delivery of my Model S on December 23rd. Even though I purchased the total AP package, my delivery person jokingly said... "oh it's not available yet, and won't be for probably a few weeks". She mentioned something about new hardware on the vehicle that was not compatible with the existing AP that other owners now have. Does this make sense?

Doublelift | 26/12/2016

joegazin -

She's right, and she is just confirming what was written on the website when you ordered. The new upgraded hardware you have is really NEW, and Tesla is currently (as they said they would) testing new software to make use of that hardware. You can expect periodic updates to your car's software in the coming days, weeks, and months to make good use of this.

I have a mid 2016 Model S with the "older" driver assistance hardware suite. For example, I have two cameras and you have eight. I of course wish I could have the new stuff that you have (it started coming out in November), but it costs too much to trade in my car for the newer hardware.

So, in exchange for a short time with less AP capabilities than I have, very soon you will have much advanced AP, superior to what I have. Relish the car today, and relish the anticipation of the great things around the corner.

All exactly as Tesla has openly disclosed since the day they announced the new hardware (people are calling it AP2 or AP2.0, just so you'll know).

Get out, drive, and grin.

joegazin | 26/12/2016

Oh I AM grinning! Thanks for taking the time to reply. I love the car...and will wait for the update.

J.T. | 26/12/2016

@joegazin Congratulations on your new car and welcome to the forum.

If you don't mind, could you give some insight into the level of research you did before buying the car. The thing is, there seems to be a lot of people taking delivery who are caught completely unaware of the fact that AP 2.0 would not be installed on the car at delivery and that most of the AP functions would not work until the new firmware is released.

Those of us who frequent the forum are well aware of this, and because of that we were also well aware that this information was readily available on the order page.

So, I'm very curious as to what you knew before you bought the car and where you got that information.

dowopdave | 26/12/2016

I didn't like the fact that it wasn't even mentioned in the update notes. That tells me that Tesla knew there would be considerable objections to it. The only reason I knew is because it was published in some articles. How many times can you press the X And not download? Indefinitely?

dowopdave | 26/12/2016

I didn't like the fact that it wasn't even mentioned in the update notes. That tells me that Tesla knew there would be considerable objections to it. The only reason I knew is because it was published in some articles. How many times can you press the X And not download? Indefinitely?

cquail | 26/12/2016

I believe your Tesla either read a sign or GPS position indicated that it was a 50 mph zone.

On some highways I have been on it reads a truck speed limit and posts it as the speed limit. If the verbiage about trucks or those towing trailers is on the same sign, my Tesla ignores it, but if the speed limit is on a sign by itself with the qualifier above on a second sign, then my Tesla applies a new speed limit.

However, on a major divided highway like I29, your car should not slow down.

joegazin | 26/12/2016

Thought I had done quite a bit of the Owner's Manual and watched all the YouTube videos. Clearly, I missed this part where this was explained. J. T., There's no need to try to denegrate. We all think the car is great, and that it represents the future of personal transportation. I was just looking for a little guidance from folks who've been driving for a while. Thanks.

EVRider | 26/12/2016

Same thing happened to me on I-75 in FL; I mentioned this in a reply to another thread. I believe the speed limit was still showing as 70 in the dash when it happened. It was the first time I've driven there in my Model S, so I don't know if it was a transient issue. It only happened when I was driving on 75S -- no problem in the other direction.

pale_rider | 26/12/2016

Same thing happened to me 4 times on a stretch of road I've driven numerous times. After the update it will seemingly randomly drop from the posted speed limit of 75 to 50. The speed limit on the dash still says 75, but there is a message that autopilot is limited to 50. No explaination why, just hits the brakes. After 500-600 yards to goes back to 75. In one instance the car behind me would have hit me had I not been able to immediately throttle up manually. The 4th instance the car inadvertently read the 30mph speed limit sign on the frontage road and dropped me from 50 to 30. Fun times...


EVRider | 26/12/2016

In the other thread about this (, in General), someone reported that it happened when he passed a car that was parked in the breakdown lane; I passed a parked car when it happened to me. Same for others?

pale_rider | 26/12/2016

I can say two of the times there was a car on the shoulder, but one of the times there was nothing there. That said, the car should slow down before it gets to the car on the side of the road, not after, if it wants to be useful...


burdogg | 26/12/2016

@joegazin - I took it that J.T. really was interested to see what you had done and how many are missing the information about the AP 2.0. I didn't take it as getting after you :) Maybe it is just how I read it, because being on the forums, we seem to know quite a bit about what is going on as every little announcement Tesla makes gets discussed to great lengths here. So then when the forums get slammed with several people starting new threads with how upset they are with AP 2.0 not working and feeling like they were sold something that does not work, we get a little frustrated :). You on the other had just asked more simply about it - so i think J.T. was just curious as many of us, how you had not known so we can then maybe extrapolate that to all the others :)

Anyway - welcome and glad you are enjoying the car. Hopefully end of this week, you will get some AP functionality (even though Elon said this, i wouldn't hold your breathe, it may still be a couple weeks :)

burdogg | 26/12/2016

J.T. - I wonder if a lot of people are seeing all the youtube videos of AP 1.0 and are making the assumption that even though they have AP 2.0 - why would it not at least do what AP 1.0 is doing. As it seams joegazin did research, but there probably isn't many videos out there (?) that discuss this point. So when you see a car with older stuff on it doing something, you assume the NEWER stuff would be able to do at LEAST what the older is doing. I don't know, may be one reason why some are so confused - they may not be reading the order page, they just see enhanced autopilot and click it without reading as they know they want autopilot? Just my thoughts on how some people may be getting confused. :)

J.T. | 26/12/2016

@joegazin I tried very hard to construct my response to you in such a way as to not come off as any kind of insult or condescension. I really just wanted to find out from someone excited to join the community and excited about their car who wasn't all, "Tesla conned me." where Tesla could have done a better job of communicating this issue.

I apologize if I wasn't successful in hitting that mark, but it's obvious to me that Tesla has simply not made it clear either on the website or in the galleries what new owners should expect on delivery.

One person missing the info is understandable, people are impulsive. Two people missing it is remarkable, but it seems like there are a bunch and that's hard to blame solely on the buyer.

Bighorn | 26/12/2016

You seemed to me to be on your best Mary Poppins behavior, so the "denigration" remark came out of left field, probably mostly out of embarrassment.

markbraukman | 26/12/2016

UBQP - I agree with what "kevin | December 25, 2016" said. Check your instrument cluster (IC) and see what is says when AP drops speed. Nearly a year ago while west bound on I70 out of Denver, my IC dropped to 55 while the speed limit was 65. Of course AP kept going at 65. That happened when I passed a sign that said "Minimum Speed Limit 55".

J.T. | 26/12/2016

@Bh I thought my remarks were practically perfect.

I'm also wondering about what the DS is talking about when handing over the key. I would think something would have to be mentioned about not engaging AP until a new firmware is downloaded. But only guys like joegazin can tell us if pertinent information was disseminated.

Bighorn | 26/12/2016

Well if you're going to get huffy... :)

Haggy | 26/12/2016

Anybody who ordered before AP2 hardware was announced but who didn't take delivery yet will potentially be unaware of the situation. I would imagine there will still be some.

fgaliegue | 26/12/2016

@bbugbee "There is a fundamental problem with Tesla restricting the AP to the posted speed that nobody, I mean nobody drives." <-- do not take _your_ behavior to be the general case. I do respect the speed limits.

Mind you, I'm in France, so default speed limits are "reasonable" enough.

As to the case mentioned by the OP, I have never experienced this myself; there is some discussion around about this, and even has an article about this -- I still have not figured out when it occurred and why, though.

Haggy | 26/12/2016

It may not make sense to anybody in France why anybody would want to disobey the speed limit at all times, just like it may not make sense to Americans why anybody would drive a motorcycle down a public stairway. All that misses the point. You should be able to use a car in a way that's normal and expected where you live.

There are some places in the world where I'd want to go below the speed limits or where the method of assigning speed limits is much different from the US. Where l live, speed limits are assigned based on individual roads and individual sections of road, and are conservative. In some countries, speed limits are set based on the type of road, meaning there might be separate categories for motorways, national routes, local and regional roads, and built up areas. If I'm on a local road in a non-built-up area, and the national speed limit for such a road is 80 kph, but the road is very narrow and curvy, I might not want to go even close to the speed limit. If I lived in such a place I might not understand why anybody would want to have the right to exceed the speed limit at all times. If somebody went into their country, looked at how fast people really drove, and the put up speed limit signs all over the place that were 10 kph lower than that, then they might understand, especially if law enforcement said that there was a margin of error for their equipment and people would get a ticket if their speed exceeded the limit by more than that margin.

tesla man 8k | 26/12/2016

I have had my car since 2012, and love it, recommended it to many and sold many, but this behavior has become the standard for tesla engineers and management, you may have purchased the car, but you have no choices on what new programs are put into it. They do not warn you that it may be different than you like, until after the update. (To late then) You may buy what you like but don't be surprised if you end up with quite a different thing. I saw this in the beginning when they raised the suspension to satisfy the three fires.( Public Relations) Another example was the changed the instrument panel to the useless car instead of the power meter, now the latest from 7.1 with all the months of improvement, to the disaster of 8.0. I think I would have preferred to pay for what I liked, and know what I was getting! Get used to it and good luck!

kevin | 26/12/2016

@joegazin So I don't miss anything, I have a daily routine.

- Visit the firmware tracker to see if any new firmware has started deploying
- Check what Tesla stock did the day before, and read any articles on Tesla at and ignore them
- Check Elon Musk's Twitter feed
- Check for blog posts on the Tesla site
- Read the Electrek web site
- Look at new posts at the Tesla Motors Club Forum
- Check
- See if Bjorn Nyland has any new videos on YouTube
- Check this forum General section, then the Model S section.

Phaeton | 26/12/2016

Today I ran into the restriction on I-495 around DC, with 5 lanes each way and a definite barrier as the median. Suddenly the car was slowing to 50 in a 55 zone and complaining that it was not a divided highway. Fortunately I was in light traffic or the people going 70 (the standard traffic speed there) would have run me over.

Previously the car did not apply the +5 restriction in that area, so it seems that possibly the database has been corrupted in the update??? I have noticed problems with the database before, especially with its delineation of what secondary roads are divided or not, and where those medians start and stop.

If the database was accurate I could almost live with the +5, but +0 is just not acceptable around DC.

Tropopause | 26/12/2016


"read any articles on Tesla at and ignore them"... so true!

Sparc | 26/12/2016

Is there any way to restore to 7.1?

lilbean | 26/12/2016


martin | 27/12/2016

To get back to the subject:
Had TACC set to a speed below the speed limit and AP on. Then I overtook a semi and for that accelerated slightly. Suddenly there was a warning in the instrument cluster I had not seen before: "Accelerator Pedal pressed. TACC won't brake automatically!". When the car had settled back to TACC speed the warning went off again.
When AP automatically reduces speed to the exact speed limit just feather the accelerator pedal and speed goes back up... tried this this morning.

kevin | 27/12/2016

I got the speed restriction this AM on I-85. Lasted maybe for 1/4 mile.

Pungoteague_Dave | 27/12/2016

What Elon giveth, Elon taketh away....

pcgray.texas | 27/12/2016

The new TACC restriction to the posted speed, instead of 5 mph over, while using AP is actually more dangerous than before. Doing so has made other drivers tailgate me and cross a double yellow to pass. I think I even got flipped off. Real world drivers generally cruise at least 5 mph over. Please give us back our 5 mph "grace" limit. By the way, are we just barking in the dark, or does anyone at Tesla read these threads?

lilbean | 27/12/2016

I hear ya. Driving the speed limit in Los Angeles could get you killed.

charles.a.braun | 28/12/2016

We also experienced the reduced & restricted speed phenomenon from the posted 65MPH (Yes the dash continued to display a 65MPH sign) to 50MPH on 3 different freeways (that we travel frequently) CA14 / I5 / CA60. These were on Christmas Eve and after downloading the latest updates. These are freeways that we travel frequently and there was no AP misunderstanding the posted signs etc.

In the first incident there was a tow truck servicing a car on the right shoulder. OK I get it, slow down but do so before the broken down vehicle not after and then resume speed immediately after passing. That did not happen. Our car slowed after passing the broken down car and didn't resume driving the speed limit until we disengaged AP and re-engaged. We weren't about to continue driving 50 on a 65MPH freeway to see how long it might take for it to resolve itself.

The 2nd and 3rd times it happened, I do not recall any broken down vehicles on the shoulder.

After the 3rd time we stopped using AP.

People's suggestion that maybe this is a result of learned behavior from data gathered by other Tesla drivers is ludicrous. If a single driver of another Tesla can slam on the brakes to avoid something on a strectch of freeway in Southern California thereby impacting the future drive-ability of thousands of other Teslas on the road at a later time is just silly to even suggest.

If this is a result of new code that recognizes when a car is broken down on the shoulder or the police are making a traffic stop, well great. I am all for it and the safety it provides to those people. Just slow the car down before I get to that scene not after I have already passed it as that does no good. At the same time, if this is a result of the new code and is not a bug and is instead an intended feature, why not tell us about it in the release notes.

I would think that drastically reducing and restricting speeds to 50MPH in posted 65, 70, 75, 80 and 85MPH zones (Yes there are a few of those in Texas) would introduce safety risks to no just me and my occupants but to all the other drivers are the road that do not expect my car to just suddenly slow to 50MPH on the highways.

Tesla takes the time to tell us how we can now drive on Mars and how we can better tune our radio but you don't tell us that our cars are subject to reduce and restrict speed to 50MPH on the freeway.

Come on Tesla, pull your head out and get with the program.

UBQP | 28/12/2016

Charles, hopefully Tesla will learn from the multiple instances reported of this odd behavior and fix this bug.

I certainly don't know if this bug is associated with Tesla's learning feature, but if it is, they need some negative feedback to avoid this kind of behavior in the future.

lilbean | 28/12/2016


kevin | 28/12/2016

@ UBQP this may be a good time to use the car's "Bug Report" voice command.

UBQP | 04/01/2017

I discussed the problem I had with Tesla Service and they seemed a bit dismissive at first, but I received a call back the next day or so and they wanted more information, e.g. time of day, location, weather, traffic, nearby exits, car on side of road, etc.

Several days later they called to thank me for the feedback. Tesla's AP information mistakenly showed that the speed was 50 on that stretch of the highway and will correct it. I haven't been able to test it yet so don't know how quickly they update their info. Apparently this firmware update incorporate some of their new "learning" tech.

I asked if the "Bug Report" option would have helped them but the person I talked to didn't seem to know what that was.....