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TSS 2.0 LTA with mm-radar adaptive cruise control impressions

Discussion in 'Prime Main Forum (2017-2022)' started by Gokhan, Jan 5, 2022.

  1. Gokhan

    Gokhan Senior Member

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    I wanted to give TSS 2.0 LTA with adaptive cruise control a good try last night, setting at 57 mph (55 mph actual speed) on a freeway.

    What I found out is that, instead of trying to keep the car in the middle of the lane, LTA lets the car drift and then intervenes when it wanders closer toward one of the lane marks. This results in a choppy lane control, as the steering wheel moves abruptly every few seconds, with nothing happening in between. A much better control would be if the steering wheel moved slowly and continuously, like a good driver would use it.

    Then, at one point driving in the rightmost lane, I noticed a slow car ahead of me trying to merge from the right onto the freeway. I gave the adaptive cruise control a chance. It didn't work. My car wouldn't care about the car merging into my lane even until I was very close to it. If I didn't intervene and brake, there would either be a collision or perhaps the AEB would kick in the last second and slam the brakes to prevent an accident.

    So, don't count on the system at all.
     
  2. schja01

    schja01 One of very few in Chicagoland

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    I use Dynamic Radar Cruise Control frequently. I don't have LTA. Cruise failed me once but it was in heavy rain which is a situation where it's not recommended to be used so that was on me. TSS isn't autopilot so you do need to be on your toes.
    Question: You don't mention the weather (rain, snow, severe clear) or your cruise control distance setting (1,2,3 bars).
     
    #2 schja01, Jan 5, 2022
    Last edited: Jan 5, 2022
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  3. Ovation

    Ovation Active Member

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    I use the Dynamic Cruise Control very frequently. It’s very effective (1000 miles a week for my work commute—I’ve used it for 80%+ of those miles over a five month period). I adjust the “distance bars” as needed in any particular situation. Also, it disengages automatically and quickly if traction is not appropriate (tested it on a deserted stretch of road). Regular cruise control does not.

    The LTA, however, is not especially useful. After about 500 miles (over several days of driving in various situations) I gave up.
     
  4. fotomoto

    fotomoto Senior Member

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  5. Trollbait

    Trollbait It's a D&D thing

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    Is it even possible to determine comma's long term performance is?

    Teslas crashing while Autopilot is on make news, and the NHSTA is requesting incident rates from other car manufacturers involving their advanced driver aids. If someone gets in a crash with it active, how many 'forget' to mention it was in use? How many crash investigators know to even look for it?
     
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  6. MTN

    MTN Active Member

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    OP, TSS is not autopilot. I cannot/does not look at other lanes of traffic for DRCC, only directly in front of the car. If a vehicle is merging or even exiting, you will want to override the system to make appropriate adjustments. I agree that the LTA also ping-pongs a bit too much - it is actually smoother in my Rav4 Prime, for whatever reason.
    The DRCC is best used when there are few on/off ramps. We still find that it is very helpful on longer drives and relieves the stress of constant speed/distance adjusting for other drivers. I've been finding DRCC is more helpful for stress relief than LTA - much of the time I'm "fighting" LTA to drive smoothly in my lane.
    Hopefully the next system gets better. I'm not brave enough to take on the liability that comma ai thingy would introduce!
     
  7. Trollbait

    Trollbait It's a D&D thing

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    TSS and Autopilot are both advanced driver aids. Pretty sure every major car manufacturer now offers such. What each suite can handle on the road is going to vary. Autopilot looks into side lanes. Others may not. Best to read the manual before using them.
     
  8. Db17

    Db17 Member

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    I use the LTA on my 2021 Prime sometimes. But it tends to wiggle in the lane frequently. Makes me wonder if I might get pulled over for drunk driving and have to explain it.
     
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  9. triggerhappy007

    triggerhappy007 Active Member

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    I've been driving a Leaf that has ProPilot since 2019. It's one the reasons I switched to the Leaf. Even though I don't have experience with TSS 2.0 LTA, I can tell that Nissan's LTA is better from what @Gokhan is describing. I can't wait to try out Ford's BlueCruise, Kia/Hyundai Highway Driving Assist 2, and ProPilot 2.0.
     
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  10. Gokhan

    Gokhan Senior Member

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    TSS 2.0 LTA is really, really bad on the Prius Prime, to the point that one shouldn't be using it. What is surprising is that TSS 2.0 LKA on the Prius Prime is truly excellent. TSS 2.0 LKA on my 2021 Prius Prime glues me to my lane while I am at a freeway merge or near other ambiguous lane markings without even a warning on the MFD, but the LTA, when it is turned on, constantly ping-pongs my car between the lane markings, which is ridiculous. It is as if the two systems were designed by two different engineers with entirely opposite skill levels.