Noticed something odd with autopilot

[fasteddie7]

Over the past two days I've noticed that twice now my vehicle automatically adjusted speed with the speed limit. I know that it always reduces speed when the speed limit changes but twice now while driving into a higher speed limit Zone the vehicle sped up. It's only happened twice and I can't figure out what is causing the behavior. Anyone else notice this?

 

[msnow]

Over the past two days I've noticed that twice now my vehicle automatically adjusted speed with the speed limit. I know that it always reduces speed when the speed limit changes but twice now while driving into a higher speed limit Zone the vehicle sped up. It's only happened twice and I can't figure out what is causing the behavior. Anyone else notice this?

It shouldn't go faster than what you set it for and it should only reduce speed if you've moved from a divided highway or expressway to a restricted road or, of course, when the car in front of you slows.

 

[TIppy]

I've noticed that if you're in a 35mph zone and have autopilot set for 45mph you'll be limited to 40 mph, 5mph above speed limit. If the speed limit then changes to 40mph the new cap is 45mph so the car will increase to 45 mph.

 

[JohnnyG]

@fasteddie7 - You aren't losing your mind, this happened to me twice this past weekend. It is behaving like it had prior to the initial release of v8.0.

I was travelling on a non-divided highway, speed limit was 40, I had the autopilot engaged and set to 45 (TACC showed "MAX 45"). I entered into a 35 zone, and the autopilot restricted me to 40 (note: the TACC now showed "MAX 40"). I continued on autopilot, and upon entering a 45 zone, my speed increased to 45 (my previous, initial, manual setting) and the TACC now showed "MAX 45" again. Note that I could technically be doing 50, but I didn't previously have it set to 50, I had it set to 45.

This behavior is exactly how autopilot functioned prior to the initial release of v8.0. The only difference is that in v7.1, it would still let you manually manipulate the speed setting to a higher speed (and display it), even when autopilot was speed restricting based on the speed limit. Theoretically, in v7.1, you could set the autopilot to 90MPH, and it would adjust your speed to 5 over along your whole route as the speed limits changed, with no intervention from you.

Side note: with this latest behavior, if you try to change the speed setting with autopilot engaged on a non-divided highway, it will not do as described above. It takes that movement of the cruise speed setting as your new setting, even if you were trying to set it to a higher setting, and visually nothing seemed to change.

Okay, now everyone go try this and report back!

 

[JohnnyG]

I've noticed that if you're in a 35mph zone and have autopilot set for 45mph you'll be limited to 40 mph, 5mph above speed limit. If the speed limit then changes to 40mph the new cap is 45mph so the car will increase to 45 mph.

@TIppy -- It sounds like you might still be on v7.1. With v8.0, you can't be in a 35MPH zone with autopilot on and set the TACC to 45MPH. It will only allow you to set it to 40MPH. However, you could be in a 40+ zone, set AP to 45, and then drive into a 35 zone, which would then limit you to 40, but as noted above, with initial release of v8.0, it would not then speed you back up once you moved into a higher speed limit.

 

[TIppy]

@TIppy -- It sounds like you might still be on v7.1. With v8.0, you can't be in a 35MPH zone with autopilot on and set the TACC to 45MPH. It will only allow you to set it to 40MPH. However, you could be in a 40+ zone, set AP to 45, and then drive into a 35 zone, which would then limit you to 40, but as noted above, with initial release of v8.0, it would not then speed you back up once you moved into a higher speed limit.

I'm on v8.0 now, but I can't say for sure which version I was on when I made those observations.

 

[fasteddie7]

Both times were from 45 to 25 and back

 

[green1]

Also a reminder that you can not count on this behaviour because it is only on certain classes of roads.

It is useful only as Tesla intended it, as a limit to your use of the feature. It is not useful as a feature unto itself because you can't rely on it.

 

[MP3Mike]

Also a reminder that you can not count on this behaviour because it is only on certain classes of roads.

It is useful only as Tesla intended it, as a limit to your use of the feature. It is not useful as a feature unto itself because you can't rely on it.

@green1 I think what people are saying is that Tesla "fixed" this feature as part of the most recent 8.0 build. Such that it remembers your set maximum and then Autosteer adjusts the TACC maximum up to your max set based on the speed limit rules. (Unlike the initial 8.0 that only reduced the set point down, it would never go back up automatically.)

 

[green1]

@green1 I think what people are saying is that Tesla "fixed" this feature as part of the most recent 8.0 build. Such that it remembers your set maximum and then Autosteer adjusts the TACC maximum up to your max set based on the speed limit rules. (Unlike the initial 8.0 that only reduced the set point down, it would never go back up automatically.)

but does it do it on ALL roads? or only "restricted" roads (where you have no idea if a road is restricted until you try)
That's my point. If it only does it on some classes of roads, it's not useful as a feature, only as a limit.

 

[fasteddie7]

but does it do it on ALL roads? or only "restricted" roads (where you have no idea if a road is restricted until you try)
That's my point. If it only does it on some classes of roads, it's not useful as a feature, only as a limit.

I have only had the new update for two days now only traveling my normal commute on national highway 40 in pa which goes between divided four and two lanes through residential to long straight aways. I'm going a different route tomorrow so I'll be able to see how it behaves then. Interstates never adjusted down for me, as i don't believe they are supposed to.

 

[TIppy]

but does it do it on ALL roads? or only "restricted" roads (where you have no idea if a road is restricted until you try)
That's my point. If it only does it on some classes of roads, it's not useful as a feature, only as a limit.

I believe the 5mph above posted speed applies to all roads that aren't divided highways.

 

[JohnnyG]

Also a reminder that you can not count on this behaviour because it is only on certain classes of roads.
It is useful only as Tesla intended it, as a limit to your use of the feature. It is not useful as a feature unto itself because you can't rely on it.

You can count on it to function as designed. The certain classes of roads are clearly specified in the Owner's Manual (residential roads, a road without a center divider, or a road where access is not limited).
Tesla intended it as a safety limit; for you AND for those on the roads and sidewalks around you. Why do you say you can't rely on it? If it functions as designed, documented, and demonstrated (not necessarily as you prefer it), then it is reliable. If it where acting randomly, then you could claim it unreliable.

but does it do it on ALL roads? or only "restricted" roads (where you have no idea if a road is restricted until you try)
That's my point. If it only does it on some classes of roads, it's not useful as a feature, only as a limit.

You know exactly what roads, because it is outlined in the Owner's Manual. Nowhere does it say "restricted". It clearly states "residential roads, a road without a center divider, or a road where access is not limited". As a licensed driver, those terms should be quite clear.
Again, it was never intended as a 'feature'. It's purpose is a safety limit, to protect you AND others from you.

 

[green1]

And I'm sure the car clearly displays to you what type of road it thinks you are on right?

I've tried the limitation, I chose to disable it. On some divided roads it was restricted, on others it wasn't, on some non-divided roads it was, on others it wasn't. There's no way to know until you try it on that specific road at that specific time.

Sure, it's mostly reproducible on the same section of road (barring a tile update which it won't tell you that it received) but until you've driven the section of road you don't know.

It is once again a "safety limit" which actively REMOVES safety. People are using it as an automatic speed adjust, when it wasn't designed to do so, it sometimes unpredictably drops your speed for no apparent reason when it misreads a sign (and sometimes quite aggressively too) quite possibly leading to rear-end collisions, and all the while it does NOTHING to make you any safer than you were before when you actually paid attention to speed limits and the speed of traffic and drove accordingly.

 

[TIppy]

I have had it drop me down from 50 to 25 abruptly when it read a school zone speed limit during a time when it shouldn't have been enforced.

 

[bradhs]

If this is true, thank god... I miss this from the 7.1 days.

 

[Pruitt]

Good! I really missed this 7.1 behavior in 8.0!
If you're in the slower zone and take the car off autopilot by jerking the wheel, does it speed back up to what you set? It used to do this, which is a potential safety issue.

 

[GlmnAlyAirCar]

If this is true, thank god... I miss this from the 7.1 days.

This is actually different (and, IMHO) better than in 7.1.

In 7.1, on "restricted" roads, you could set the TACC (with autosteer activated) to any speed desired. However, the actual speed would be capped at the greater of either the selected speed or the speed limit +5mph.

In the current build of 8.0 (2.42.40), the behavior IS a little different. On restricted roads, if you attempt to set the TACC (with autosteer activated) to anything greater than the speed limit, it will cap it at the speed limit+5. Period. Except, now, when the speed limit increases, so will the TACC speed, even if it is greater than the speed you were traveling when it was originally set. In this build, it is truly following the speed limit.

In the original 8.0 builds, TACC speed would never increase on its own.

Note that this only applies to restricted roads with autosteer activated. On unrestricted roads, or without autosteer, it will still continue to hold the speed you set.

 

[GlmnAlyAirCar]

Good! I really missed this 7.1 behavior in 8.0!
If you're in the slower zone and take the car off autopilot by jerking the wheel, does it speed back up to what you set? It used to do this, which is a potential safety issue.

No, because it no longer "remembers" the speed that was set prior to engaging autosteer.

 

[green1]

Except, now, when the speed limit increases, so will the TACC speed, even if it is greater than the speed you were traveling when it was originally set. In this build, it is truly following the speed limit.

So it ignores the speed you told it to do and accelerates beyond that? That sounds like an extreme safety risk!

Keep in mind this is the car that half the time has no clue what the actual speed limit is.