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Dynamic Cruise Control and erratic drivers

Discussion in 'Gen 4 Prius Care, Maintenance and Troubleshooting' started by annexedwa, Apr 6, 2016.

  1. annexedwa

    annexedwa Junior Member

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    How does the system handle a car suddenly slowly stopping in front of you. I've noticed that when a car merges and slows down suddenly, the Prius will almost slam on the brakes and I'm worried a car will rear end me. What say you?
     
  2. JC91006

    JC91006 Senior Member

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    The system worries about what's in front of you.....not what's behind you.
     
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  3. DonDNH

    DonDNH Senior Member

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    Prius can only handle avoiding what's in front of you. If the person following you is too close, he risks running into you; but that's not what DRCC is trying to avoid. When someone is tailgating me, I will take action to discourage that behavior such as encouraging them to pass me or moving to the right.
     
  4. bwilson4web

    bwilson4web BMW i3 and Model 3

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    You should not worry. To remove all doubt: just slam it into "R" and floor the accelerator. <grins>

    Consider the alternative. Would you prefer to hit the car in front?

    Bob Wilson
     
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  5. fuzzy1

    fuzzy1 Senior Member

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    Does the degree to which the Prius slows down seem reasonable based on the situation in front? If so, then it is working correctly.

    Generically speaking, hitting the car in front is not a reasonable approach for avoiding getting hit from behind. Any special corner cases where the former really is preferable, are also beyond the capabilities and judgement of existing automatic systems.
     
  6. annexedwa

    annexedwa Junior Member

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    it does not seem reasonable! It slams on the brakes anytime I get cut off, even if the vehicle cutting me off is not slowing
     
  7. DonDNH

    DonDNH Senior Member

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    It's going to slow down to regain distance to the jerk who cut you off because if he slams on his brakes, you still want to be able to stop in time. DRCC does its best to give you the opportunity to avoid a collision.
     
  8. fotomoto

    fotomoto Senior Member

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    Regardless of distance between you and them?
     
  9. kevindb

    kevindb Junior Member

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    I've noticed a distinct difference in behavior of the DRCC between getting cut-off and traffic ahead slowing/stopping. When I get cut-off, and the driver is maintaining mostly the same speed as myself, the DRCC will simply let off the accelerator to allow a safe distance to build up again. It does NOT hit the brakes, even if the distance is very short, as long as he is moving the same relative speed as me. If car in front of me is slowing (compared to me), that's when the DRCC uses the regen/brake.

    This sounds consistent with your observed behavior: if there is a car close in front of you and it is driving slower than you are (indicating a collision is imminent), the DRCC brakes to match speed and avoid a collision. I agree with DonDNH that cars in the right lane seem to be less interested in tailgating. You may want to spend some time in the right lane, and enjoy the fuel efficiency gains from driving at a lower speed. :)
     
  10. minnyprius

    minnyprius Member

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    I have the old 2012 version of the system, and yes, sometimes it over-reacts, and slows too much/too quickly, I anticipate that and either cancel the cruise before hand, or lightly depress the go pedal to tell the car "It's ok, Pearl...."

    85% of the time, though, I **LOVE** adaptive cruise control.
     
  11. I'mJp

    I'mJp Senior Member

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    Your foot on the accelerator will always override what the cruise wants to do.
    If some one cuts you off and you don't want to give it space, push on the accelerator...
    jp
     
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  12. Lawrence Rosenblum

    Lawrence Rosenblum New Member

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    Interesting. I'm finding that DCC is more laid back than me when I'm cut off. It seems to decelerate slowly, if at all, depending on how fast the car in front is going. I have it set to follow at the furthest distance from the car in front and I wonder if that may explain our different experiences.
     
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  13. annexedwa

    annexedwa Junior Member

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    Whatever you do, never press the go pedal when in traffic as it slams on the brakes when you let go.
     
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  14. bwilson4web

    bwilson4web BMW i3 and Model 3

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    Yea, but what if you want to ram the SOB! Anther alerative approach.

    Bob Wilson
     
  15. minnyprius

    minnyprius Member

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    Being "cut off" and having someone merge in front of you are two very different things. If you have it set at the longest following distance, people will always have enough room to get in front of you. In that situation, yes, it's much more gentle at adjusting and re-creating that space again. But in rush hour traffic, say, 30-40 mph, shortest following distance, and an opportunist jumps in front, the car doesn't like that. That's when I know to either cancel the cruise so I can manage it myself, or lightly push on the go pedal to reduce it's response and then gradually let back off when everything is happy again.
     
  16. annexedwa

    annexedwa Junior Member

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    The problem with the furthest distance from the other car is the cars behind you hate that and become aggressive. Is there any chance of an update to the system? How does Toyota implement updates? Over the air through entune and your phone or flash from the dealer?
     
  17. minnyprius

    minnyprius Member

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    I only use the longest following distance in the middle of nowhere, and even then, rarely. I almost always use the middle setting, but in heavy traffic, I use the shortest. I've used it enough to trust it will react quickly enough to most situations. But I'm always ready to take over anyway.
     
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  18. jdenenberg

    jdenenberg EE Professor

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    Updates are done during a dealer visit, not over the air.

    My wife's 2016 Subaru Crosstrek has "Eyesight" and an analogous smart cruise control. It also sometimes slows down more abruptly than I would when the distance between it and the car in front diminishes. I did not notice abrupt braking when cut off.

    JeffD
     
  19. I'mJp

    I'mJp Senior Member

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    If the car that just moved in front of your is going ever so slightly faster than you, the cruise does respond "laid back"

    If the car in front is = or less than, that's when the cruise react quickly.

    It's sorta weird, following in the middle lane a car at a respectable distance, and having a car in the left lane pass you, switch to the far right lane right in front of you, and the cruise control could not care less.. no reaction at all.
     
  20. ETP

    ETP 2021 Prime(Limit),Highlander HYB Plat,B52-D,G,F,H

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    I think the sensitivity is adjustable. Not sure????