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TACC override +5/-

Discussion in 'Model 3: User Interface' started by wcorey, Mar 24, 2019.

  1. wcorey

    wcorey Active Member

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    Does anybody have insight on this? I love the fact that TACC, determined by geocoded speed limit, can be overridden. I am shocked just how lackadaisically some jurisdictions code their streets and highways. So I believe there are two principal reasons for overriding:
    1) The speed limit is properly coded but is laughably lower that prevailing traffic.
    2) The speed limit is improperly coded as in coded for 30 in a 50 zone or coded for 50 in a 30 zone.

    What I have found is it is virtually impossible for me to get it to work right. What I'd like to see is overriding is only in force until the next geocoding is sensed which resets the speed to the new, presumably correct, speed limit.

    I believe it is safe on the high side in that the speed is limited to 5 mph over geocoded speed limit. It's on the other side where I perhaps had overridden the speed limit and the speed limit goes up but the car maintains to lower speed. This forces the driver to constantly be adjusting the override speed. What would be nice, maybe it exists, is to tell TACC override value is zero. What's troublesome is one would think setting the override to be the speed limit should accomplish that but that is the root of this problem. Maybe it would be better if the override value dialed in is +/- some number where zero would be no override.

    It used to work better. I believe a recent update 'broke' it. Any thoughts?
     
  2. ewoodrick

    ewoodrick Active Member

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    TACC shouldn't have the speed limits associated with it, that's autopilot. If in single click down TACC, I believe you can adjust the speed limit as you desire.

    In double click autopilot, it's limited with no override. It's not the municipalities that's the problem, it's the data source that Tesla is using and it is quite dismal. My Garmin GPS will essentially always have the right info, the Tesla, may 70% and as you know, not only can it be missing, it can be downright wrong. The road in front of my subdivision has been 50 mph for probably 50 years, but the car thinks that it is 40.
     
    • Like x 1
  3. wcorey

    wcorey Active Member

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    Really? I assumed Tesla got the information from Geocoded highway information produced by the governing body. I used to work with Manifold, a geocoding software system. Our son has a Mazda which displays and uses the highway segment specific info. That is only produced by one source, be it the state, city, or town.
    Just today, NoA, which incorporates TACC let me do 65 in a geocoded 50 mph zone. It is clearly broken. When I first turned it on, 40 mph zone, it showed speed at 41. No, it needs to be tethered to the actual posted speed limit. Hopefully soon it will optical character recognition (OCR) speed limit signs.
     
  4. asianxtreme

    asianxtreme Member

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    ewoodrick is correct. TACC does not have speed limit, only E/AP

    The simple solution would be for Tesla to image process the local speed limit signs (then save it in their database).
     
    • Like x 2
  5. RTPEV

    RTPEV Member

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    Not sure how "simple" processing speed limit signs is compared to just using an accurate data source in the first place, but even this doesn't address what I think the OP's original point was.

    Well, to clarify, some of the behavior the OP reported is similar to my experience, at least in the sense that a recent update "broke" something.

    In my case, it's all about interchange ramps. I travel on an interchange ramp (between two limited access highways) that are essentially high speed ramps. The speed limit on one highway is 70, and the other is 60. Technically speaking, I don't think the new speed limit applies until you are actually on the new highway (and there certainly are no speed limit signs until you get on the new highway--not even advisory (black on yellow) signs). But a recent update caused AP to transition down to 45 mph for a brief time on one of the ramps. I actually get several transitions: one from my set speed of 74, then down to 70, then to 65, then to 45. Unfortunately 45 is WAY too slow for this particular ramp. Most people are still driving between 60 and 70 on this particular ramp).

    Coming from the other direction (going from the 60mph to 70mph highway), I don't think I am getting actual AP speed changes, but the car itself does sometimes slow down significantly. I think this is due to the fact that while this is even a higher speed ramp (it's pretty much straight), there is a couple of crests on this one that causes the car to cautiously slow down more than feels comfortable (but I do understand why it does so).

    For the former issue, I suspect that eventually another update will "fix" it, as has been the case in the past. It's just annoying that it keeps coming back.
     
  6. wcorey

    wcorey Active Member

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    Yes, you are correct...I suppose. You don't get TACC w/o EAP. The issue there is with a single swipe of the right hand stalk will it conform to the 'posted' speed limit. The reason I do a suppose is I virtually never use TACC (single swipe). I use EAP almost ALL the time, even back roads. If the steering wheel icon is lit, I use autosteer. Something clearly changed recently with how the speed limit is 'set' and adhered to. It used to, in the last 4 months, work way better.
     
  7. wcorey

    wcorey Active Member

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    Thank you, you understood my point. Before I even reserved the Model 3, in 2017, I was speaking to a friend near San Diego about TACC, TA part specifically. My Prius Plugin Advanced (2012) had radar adaptive cruise control. It would slow down on approaching slower traffic...better than being distracted and plowing into slower traffic. My question to him was will TACC also speed up to keep up with the flow of traffic. Likely every jurisdiction as a road or segment where the posted speed limit is laughable compared to the flow of traffic. One major complaint I have with NoA is it's insistence on moving from the slow (entry/exit) lane to the passing lane. This is esp true on two lane limited access roads where the 'thru traffic' lane IS the passing lane. I let EAP set the speed to the 'posted' speed either by my seeing speed limit signs or the software depicting what it perceives to be the speed limit. Doing the speed limit in the passing lane is just rude. So my question about TACC was will it speed up to stay with the existing traffic. Doing 55 when everyone is doing 70 is way worse than doing 70 when everyone else is doing 55. TA does stand for traffic aware, right? I perceive this is precisely what you referred to.
    Now, on the posted speed vs geocoded speed, when the software can decode speed limit, exit ramp speed, yield signs etc when there is a discrepancy between posted speed and coded speed it should likely favor posted. Similarly if it detects all other lanes are doing +5 - +10 faster than you are it should favor that speed. Of course there is something to be said for letting others run point and get the ticket not you.
     

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