Cruise control slowdown in curves

[Mathme]

Yep...it's annoying as....well, it's really annoying. I find this feature unnaturally upsets the dynamics of the truck in a corner and once it starts its game, I turn cruise off. This even happens on the interstate -- if you've ever driven from Shasta Lake to Shasta on I-5, you know what I mean.

Lane Keep Assist is nice however, it also gets turned off as soon as the road gets twisty as I don't necessarily want to stay in the EXACT CENTER of my lane ALL the TIME.

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[bigsky]

I myself do not trust Rivian Driver+ yet.
Not sure how it can work in roundabouts when I believe this feature works on mapped roads, i.e., interstates.
Tesla FSD, light years ahead, is a completely different and better animal. Handles roundabouts now perfectly.
Also, Tesla FSD does tend to slow down when taking curves. I would think that this is a good thing.

 

[Meash20]

I just press the skinny pedal..

 

[Riviot]

lol the whole point of cruise control is not to use your foot. The original post has valid concern. I also noticed this and I think it's potential safety concern.

The safety Rivian (both the company via programmers, and the programmed vehicle itself) is concerned with is your speed in a curve. It either can't see far enough to accurately apply the right acceleration, or it requires turning further than its Driver+ limit.

Think of the accelerator as the "reassurance" button, telling your Rivian "it's okay, you got this!"

Watch this display next time it slows in a curve. I bet if you maintain speed instead of letting it slow, the little triangle gets small, meaning "too much turn, boss!" It occurs between 24-25°.

To all of the other curious folks on this or any other "Rivian problem," investigate the "problem" yourself and offer up your results to the group. It doesn't have to be a rigorous defensible dissertation, just give it the ol' college try before whining, you're very capable. Half of us are grease monkeys, half of us are computer-y nerds, and the rest fall somewhere in between (don't check my math, I work for the government).

https://www.britannica.com/science/scientific-method

 

[SwampNut]

It's extremely stupid behavior, and goes into my list of reasons why nobody should own a Rivian instead of a Tesla unless they need a truck. That was my only reason for changing. Waited too long trying to get a CT, and the Lightning is a bad joke.

 

[bd5400]

The slowing in curves in one of the most frustrating aspects of day to day Highway Assist usage for me. It slows down on curves that absolutely don’t need reduced speed, which then just annoys not only me (because I can feel it) but also cars behind me, which sometimes results in people trying to pass me only to have the truck speed up again after the curve.

I’ve wondered what the criteria is and whether curves get flagged with Highway Assist mapping or whether it uses the live data from the car. It doesn’t seem to slow to a set speed, so it’s not like the car is saying “X mph is safe for this curve so I will slow to X”. Instead, it just seems like “Flagged curve ahead, reduce speed a few MPH”, which is pretty meaningless if it’s not dynamic.

 

[jfoonly]

I’ve wondered what the criteria is and whether curves get flagged with Highway Assist mapping or whether it uses the live data from the car.

It seems to me to slow proactively on mapped roads and reactively in the middle of a curve on some unmapped
roads (HA not available).

 

[SwampNut]

I’ve wondered what the criteria is and whether curves get flagged with Highway Assist mapping or whether it uses the live data from the car.

It seems to coincide with passing the yellow speed warning signs. It reads the white speed limits, maybe those too?

 

[NC-Rivian]

When I’m in cruise control or adaptive cruise control on the curvy interstate I drive on, my R1T will slow down by 2-5 MPH in curves. This makes my cruise control worthless, as it makes traffic behind me slow down when there is no need to slow down. Is there a way to turn off the curve slowdown?

Many roads in WNC are curvy as they snake through valleys and the curve event is very frustrating. It sees that curves to the right showing the guardrail ahead are worse offenders than lest hand curves where the guardrail disappears. Anticipating the behavior, I keep constant pressure on the accelerator until the “curvy road” symbol disappears.

 

[MrMusAddict]

It seems to me to slow proactively on mapped roads and reactively in the middle of a curve on some unmapped
roads (HA not available).

It seems to coincide with passing the yellow speed warning signs. It reads the white speed limits, maybe those too?

Proactive behavior:

• If the camera detects an advisory reduced-speed limit sign, or
• If the road has been pre-mapped with Driver+, and some software engineer marked that particular curve as requiring a slowdown

Retroactive behavior:

• If neither of the pro-active scenarios are true, and the vehicle senses that the curve is suddenly too sharp to maintain its current speed.

 

[RivAW]

lol the whole point of cruise control is not to use your foot. The original post has valid concern. I also noticed this and I think it's potential safety concern.

....and you don't see the potential safety concern with keeping the speed constant through curves of varying degree if the software doesn't think it can keep the truck within the lines? Generally speaking, we are supposed to slow down entering curves.....if you don't like it and it occurs in the same areas regularly, take control before you get there and re-engage Drive + after. It's driver assistance....it's not supposed to do the driving for you (at least yet)...

 

[Brian A]

I have to agree. This is annoying and should be able to be turned off. I don't have this issue with adaptive cruise on my 2022 Tucson PHEV. It has a setting to turn this slow down thing off. Rivian also needs to raise the limit for cruise above 85mph. When I am in with others doing 88 to 90 I end up driving without the cruise. I don't have this issue on any other vehicles.

 

[SwampNut]

if the software doesn't think it can keep the truck within the lines?

If the software knows that it's garbage, then yes, it should take care to be safe. What a terrible solution.

 

[s4wrxttcs]

Lots of curves in Pacific County on US-101. My primary reason for wanting Cruise Control is to avoid inadvertently speeding and getting tickets.

In dry weather, Rivian's ACC slows me down a little more than I'd like in the curves.

In wet weather, ACC doesn't quite slow me down as much as I'd like.

I'm happy if Cruise Control gets me close to the correct speed, without going so fast as to attract police attention. As long as I'm getting that, I can "fine tune" my speed with accelerator and brake, or turn off ACC when appropriate.

Best to all!

I use it mostly for the same purposes and road types. The cops in these parts are serious about the speed limit.

My biggest issue with the slow down is where it occurs and not so much the degree of the slow down. It slows while in the curve when it should slow down BEFORE the curve.

It needs a little Sony AI racer technology.

 

[s4wrxttcs]

Yes there is a setting in Driver +

What setting are you referring to? I don't see any setting to enable or disable slow downs in corners.

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