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2021 Lane Tracing

Discussion in 'Prime Main Forum (2017-2022)' started by Db17, Feb 26, 2021.

  1. Db17

    Db17 Member

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    I have been very pleased with the refinements to the safety systems in this new 2021 as compared to my 2017 Advanced. And I just made my first 200 mile long freeway trip using the LTA on the new 2021 Prime Limited. I had really only tried it out on city streets before now with mostly mixed results. So on a freeway with the curves and bends you would expect to find while running at freeway speeds the car will pretty much completely drive itself. You do have to keep your hand on the steering wheel or you get a warning light.

    But I have two issues with the LTA. Number one is it feels weird to have the steering wheel make little corrections by itself and I found that little pressure over a three hour drive played havoc with my shoulder as your reaction is to constantly push back just a little. It adds up over time and my shoulder was pretty sore by the end of the trip.

    Second issue is I don’t feel comfortable with where the LTA considers the center of the lane. To me it feels like it favors moving you to the passenger side of the lane. My personal driving style prefers me to favor the driver’s side of center as I find it much easier to reference my distance to the line on the driver’s side as I can see exactly how close the side of the car is to the line where the passenger side of the car to the line I have to estimate. Does anyone know if the LTA can be re-calibrated so I can drive to my personal preference?
     
  2. Elektroingenieur

    Elektroingenieur Senior Member

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    The Owner’s Manual (PDF) lists a handful of LTA-related settings on page 247, but neither it nor the Repair Manual (more info) describes a way to adjust the car’s lateral positioning within the lane.
     
  3. yaun

    yaun Member

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    It does indeed feel right of center-ish. Maybe they did it to have more margin of error for oncoming traffic?

    I do find the system hard to use. In the left/middle lane of a highway the right centric positioning makes me fight the system too much when other cars are to the right. My preferred use is in the right lane of a highway. The only problem there are on/off ramps. If they are not well marked the car sometimes tries to re-center in the wider lane or looses tracking entirely. Off the highway the system is not very useful here in suburban MA. There are just too many driveways so that it frequently looses the right line.

    My main problem on the highway is with how opaque the system is. The only information you get from the display is if it can detect the lines. So when it steers I never know if it is just to re-center or if it has a bigger perception problem and I need to intervene. Since I prefer to err on the safe side I fight the system too much. It would be great if it could display the bigger picture of what it perceives, such as how centered in the lane it thinks it is.
     
    #3 yaun, Mar 4, 2021
    Last edited: Mar 4, 2021
  4. Tideland Prius

    Tideland Prius Moderator of the North
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    The LDW w/ SA on the 2017-2020 Prime's show a steady steering wheel light (can't remember if it's green or amber) when it corrects, does LTA do the same?
     
  5. Henrik Helmers

    Henrik Helmers Active Member

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    I feel mine is was positioned too close to the middle. There's like a constant tug-of-war between me and the car. I think I would enjoy it more if it exerted only a small amount of force, increasing as the vehicle approach lane "edges".

    Currently I turn LTA on when I'm going to adjust settings or fiddle with the infotainment. The added safety on demand is nice.
     
  6. mikpooh2

    mikpooh2 Junior Member

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    Finding this thread explains a lot. I didn't take much time at the dealership to learn all of the newer features since I've been a long time Prius owner and my latest was a 2019. I brought home a 2021 Prime Limited yesterday and I wondered if the car had an alignment issue or if I was just imagining things over a rough roadway. I've got my manual out and started reading and searching the chats and now understand that it is the lane tracing. It feels a little odd, but maybe just something I need to get used to. I do a 45 mile commute mostly over a country highway, winding roads so this will either be a really nice safety feature for me, or I will be fighting my car the whole way. No matter, I still love a Prius.
     
  7. Db17

    Db17 Member

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    After experimenting around a bit ... it seems to track better after I adjusted the sensitivity to high from standard.
     
  8. Gokhan

    Gokhan Senior Member

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    Yes, LTA corrects too frequently and sharply, instead of making slow, smooth correction. Nevertheless, it will come handy if you feel you need a copilot.

    I'm not sure if it actually doesn't center exactly or it's the driver's perception or the centering position varies according to the conditions. I wouldn't mess with the adjustment.

    As for your shoulder, it has nothing to do with the car. You have a shoulder injury, and you can try exercise and physical therapy. You can learn them on the Internet or pay a professional PT center.
     
    #8 Gokhan, Mar 7, 2021
    Last edited: Mar 7, 2021
  9. Gokhan

    Gokhan Senior Member

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    I tested the LTA centering tonight. It sometimes centers close to the right and sometimes to the left. Therefore, it's not clear what is going on. However, in any case, it's not unacceptably close to the lane mark.
     
  10. Db17

    Db17 Member

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    Thank you doctor, what would I do without you? :)
     
  11. Selbyevers

    Selbyevers Junior Member

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    My experience so far.. My first few times using the Radar Cruise with the LTA on I felt like I was fighting the system the whole time and it felt like the car was a ping pong ball bouncing between the the lane lines and I kept getting the pop-up image of the radar cruise screen. I then changed my screen in the center of the gauges to the radar cruise screen and then you can see in real time when it recognizes the lane lines and then it will show the "barriers" (or what it seems to me) and then its completely engaged and all you have to do is keep your hands on the wheel. I found if I don't resist the automatic movements in the steering wheel then it does it's own thing.
     
  12. yaun

    yaun Member

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    While LTA is engaged and lane markers are recognized there is a constant green light of a steering wheel on the dash. It's always on, regardless if/how-much steering force is applied by the system at a particular moment.
     
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  13. PiPLosAngeles

    PiPLosAngeles Senior Member

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    My LTA constantly goes back and forth like a bowling ball in an alley with bumpers. It drifts to the right and the corrects to the left, then corrects to the right, and then corrects to the left, etc. I imagine it makes it look like I'm drunk, but it's probably not that visible outside the car.
     
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  14. rdgrimes

    rdgrimes Senior Member

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    Check your tire pressure.
     
  15. Db17

    Db17 Member

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    Mine does the same and I corrected my tire pressures to 35 lbs even though my dealer delivered the car to me with the tires at about 45lbs
     
  16. Gokhan

    Gokhan Senior Member

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    Exaggerated but, yes, that's how it is.