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TACC automatic speed changing driving me crazy in DFW

Discussion in 'Model S' started by quickstrike12, Sep 2, 2018.

  1. quickstrike12

    quickstrike12 Member

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    Any owners in the DFW area out there?
    I drive everyday on the 35W (and a couple other places in the area) where there has been new expressways in the past year or so opened. I used to be able to enjoy AP every morning on the way to work helping take the load off of my sleepy ass while I sip coffee and wake up(yes I’m paying attention). But I haven’t been able to do that in months now. The TACC speed set in the IC is constantly changing speeds all the way down the freeway. Literally from 75 down to 35 then 60 then 45 and on and on. I gave up trying to keep resetting it back to desired level. It’s essentially useless for me now, at least to and from work and on this freeway.
    I realize it’s the construction and new freeways and not necessarily The cars fault altogether but geez it’s been going on for a while like this now. I have learned to live with APs little imperfections and I still love how great it is at sharing the load of driving with me. But I will sure be happy when this is someday corrected.
    Maybe a bug report wouldn’t hurt? May try that even if it’s just to make me feel better about trying something.
    Any other DFW owners suffering from this?
     
  2. quickstrike12

    quickstrike12 Member

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    Sorry didn’t realize my basic essentials were not in my signature area(maybe I’m still too new to the forums)
    2017 MS with AP2 still on 28.5
     
  3. Snowstorm

    Snowstorm Active Member

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    TACC and autopilot will automatically change the set speed if it thinks you are on an on-off ramp. Are you in one?

    If not, it probably confused a normal guest to an ramp or thinks you are on one. I don’t think there is much you can do save for trying to drive in a different lane so maybe your position won’t be confused. Do send a email to Tesla to report it so they can fix it. Probably occurs in other areas as well.
     
  4. Mark_T

    Mark_T Member

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    I know the area the OP is talking about, I suspect it is just that the database hasn't kept pace with the huge changes there have been in that area over the past few months.
     
  5. henderrj

    henderrj Member

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    there is a highway I frequent up here in the Great Northwest where is the speed changes from 40 to 50 and sometimes in as little as 1 second. I've sent in a bug report to Tesla to no avail. Somebody told me that the speed information comes from TomTom. I have an AP1 car but, I'm not sure that makes any difference in this case.
     
  6. quickstrike12

    quickstrike12 Member

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    I appreciate the feedback.
    I have experimented with various lanes and times of day as well as closely paying attention to underpasses, exits, etc......I can find no real rhyme or reason to what it’s using for it’s lookup tables in the database. But this particular highway has been under construction for a long time and now has a “expressway version” with two additional lanes on it (high speed pay lanes) that have obviously changed things up a lot. Just as a reference it resets speed no less than 5 times in 10 miles.
    Oddly enough tho the speed limit sign in white on the IC shows sometimes 60mph or something else, but TACC resets to 35,45,55 or whatever seemingly independent of what that speed shows. The actual speed of highway is of course 70.
    Not much i can do except to wait for databases to catch-up I guess. But is frustrating.
    Makes me very curious and a bit skeptical how this long awaited version 9 is going to be so much better and move closer to the mythical on ramp to off ramp EAP.
    Hoping to be pleasantly surprised tho :cool:
     
  7. BerTX

    BerTX Supporting Member

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    If the car thinks it is on the divided highway, it shouldn't be reacting to changes in speed limits. The problem is likely due to it thinking you are on the underlying city streets below the new/changed freeway route. As you cross those streets, it is thinking you should be limited to those speeds (since AP only restricts speeds on undivided roads, usually) and it sets your limit to the street it thinks you are on.

    You should still be able to use TACC without Autosteer, since it doesn't react to speed limits unless you tell it to do so.
     
  8. AltairIV

    AltairIV Member

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    I’m a daily Dallas North Tollway (DNT) driver (v28.5). I’m having the same issues on the southbound side near Rayburn. Drops from 70 to 45 in the blink of an eye. (There’s also a couple of phantom braking locations around Loop 12/Lovers/Mockingbird. I assume that’s from the combination of the hills and huge signs mounted on the overpasses.). Not sure if the speed issue occurs on the northbound side, seems like I’m always heading north in stop & go traffic. A lot of DNT construction, but always done after-hours.
     
  9. quickstrike12

    quickstrike12 Member

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    Interesting....I’ll try ONLY using TACC without Autosteer to see if still tries to reduce my speed. Didn’t realize it would react differently with or without AS being coupled.
    I tend to just rest my foot on the accelerator on this freeway and force it to continue its speed. Annoying but it works.
     
  10. Ciaopec

    Ciaopec Reservations at Restaurant at Universe end

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    Where does it drop to 35? Near an I35 sign? My car will drop from 65 to 25 on Ohio route 25 (thats an unsettling speed change surprise). And occasionally allow 65 (on an otherwise 45 limited area) on Ohio 65. The car is reading route signs as speed limits. I have a 2016 autopilot 1 car. I personally never use autopilot in construction zones. School of hard knocks reasoning as there are too many things to go wrong. For instance: construction on I75 requiring all northbound lanes to cross over to southbound lanes with a long sweeping curve and heavy white lines. I tested the AP and it wanted to continue north without regard to lines several times. Orange barrels or cones accidentally moved, etc. Just not worth the risk to me. YMMV
     
  11. Mark_T

    Mark_T Member

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    OP is on AP2 though so it is not reading signs any time soon :)
     
  12. quickstrike12

    quickstrike12 Member

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    @Ciaopec
    I can sure understand not wanting to mess with AP in construction areas. For us Dallas Fort Worth residents that’s about all we have left these days. Lol.
    I’ve looked for signs it could be reading along the roads. Don’t really see any that could be influencing the speed changes. I’ve been out on 75 and also 183 lately towards Dallas and I have also had numerous phantom breaking out that way.
    With all the new freeway roads being widened and new construction along with giant overpasses and bridges etc....I think it’s something we are going to have to live with for the near future.
    At least until such time as the maps system whatever they are using for speed control catches up with the changes.
     
    • Like x 1
  13. UncaNed

    UncaNed Member

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    How can one "Email Tesla" and expect it to be read by them? Other than emailing my sales reps from when I bought my X75D, (they've been very responsive and helpful). In fact, it really seems like, after I complained about excessive AOP2 nags, the next day somehow they had improved the nag situation. Once I complained that it was like a light show every time I approached my Tesla at night with the fob in my pocket - and shortly thereafter the car seemed to stopped doing that; are they wirelessly changing my car between software updates just for me? It sure seems like it!
     
  14. AltairIV

    AltairIV Member

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    I think I figured out my issue during a southbound trip on the DNT today. I was in the far left lane and didn’t have the diving MPH issue....I started thinking about what @BerTX said and realized the only time I’ve experienced the diving MPH is when I’ve been in the far right lane. That far right lane used to be an exit-only lane and has since been repurposed in the last 4-6 months as a 4th southbound lane. ...soooo, I think the car is under the impression that I’m attempting to AP at 70+mph on an off-ramp and isn’t having any of it.
     
    • Informative x 1
  15. quickstrike12

    quickstrike12 Member

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    That makes sense.
    I will expirement a bit more on 35W in the morning. I’ll try a different lane and watch closely.
     
  16. Mark_T

    Mark_T Member

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    I suspect it is going to be harder to get a work-around' on 35W as the changes there are a lot more complex and vertically overlap with previous existing slower speed roads below in many places.
     
  17. mmoran

    mmoran Member

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    Hmm, I started having the same problem here:

    Google Maps

    Right after the intersection of Saucon Valley Road and Rt 378 going west on 378 I'm running 55 and then all of sudden I'm down to 35. I've almost gotten rear-ended several times. I have a new appreciation for "Be Ready to take over at anytime" at that stretch of road. It only happens westbound, no issues eastbound.
     
  18. quickstrike12

    quickstrike12 Member

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    @Mark_T
    Not so much looking for a workaround anymore as I am just trying to understand what’s happening. All the new fast lane expressway have totally lost the Nav system from being up to date.
    On another note I freaking hate these “pay to play” new expressways we have. Would cost me almost 9 bucks a day round trip to work if I need to use them.
     
  19. jimmyz80

    jimmyz80 Member

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    My 2017 S75D AP2.0 does this too on the freeways in Raleigh, NC. I'll have it set to 75MPH on a 70MPH stretch, and then randomly it'll reduce itself to 70 for 10-15seconds, and then resume back to 75MPH. I file a bug report each and every time it does it - probably up to 50 or so by now. :p
     
  20. jrad6515

    jrad6515 Member

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    I agree with all of this. I drove to Dallas from Fort Worth on 183 last week and it was clear that the nav system thought I was on adjacent streets in the many construction zones along the way, enough to where the turn-by-turn instructions were useless. I did find that the automatic slowdowns while on AP2.5 did not occur while on TACC. Hopefully the DFW maps will be updated soon.
     

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