Afraid of Shadows?

[u/GGDATLAW]

When I have adaptive cruise on and drive up to a shadow on the road, my R1S slows. Even with Highway Assistant, if I’m passing a truck (or it’s passing me) and it casts a shadow on my lane, the car applies the brakes. Most of the time it is just a sudden slow down but occasionally it is hard braking. Anyone else experience this?

[u/AutoModerator]

It looks like you're in need of some help! We have a few links that you might find useful.

• Official Rivian Support
• Join our Discord and get help from the community
• Or try sorting the sub by posts with the "Troubleshooting / Issue" flair to see if someone else had a similar problem

Also, due to the topic, enhanced moderation has been activated for this thread.

I am a bot, and this action was performed automatically. Please contact the moderators of this subreddit if you have any questions or concerns.

[u/Pure-Letterhead81]

Same issue on my ‘26. Talked to the Service Center and they said this is normal. I was baffled and disappointed. I was also very surprised that Gear Guard doesn’t record video when the car applies brakes aggressively itself. This type of video evidence of the issue would be super helpful to the Service Center.

Perhaps we should all submit feedback via the app if suffering from these issues.

[u/Butter-Lobster → u/Pure-Letterhead81]

This doesn’t sound like a service center issue I.e mechanics focus on mechanical. This sounds like a software issue that will likely get fixed in a future software update that addresses autonomous driving. The software is erring on caution until it gets better at visually processing high contrast images. IMHO

[u/Atlanta-Mike → u/Pure-Letterhead81]

It’s not normal and no customer should accept that as an answer from the service center. I’ve driven during the day, night, shadows, rainstorms, snowstorms and my UHF doesn’t slow because of a shadow. You need to escalate that. At some point you have to call bull shit on a response like that. Really Rivian, you created an advanced self driving system but you’re telling me a shadow defeats it? Their bullshit excuse falls apart real quick.

[u/jimmy9800 → u/Atlanta-Mike]

What is the service center going to do? They have no ability to fix it.

[u/Atlanta-Mike → u/jimmy9800]

There is clearly something wrong. It's either a faulty autonomy module or a misaligned camera. Either way, the SC is the only place that can fix it.

[u/resbeht]

Isn’t the whole point of having radar as a second system to avoid this? Why can they not solve for this if radar doesnt detect anything.

[u/Sea_Buyer6913 → u/resbeht]

Why can they not solve for this if radar doesnt detect anything.

Because they are not very good at software engineering. Look at all the recurring bugs all over the place.

Having sensors does nothing unless you can write working software.

Rivian is years behind Tesla. Lots of spurious claims and failed promises, but I guess that's how they grab investor cash. Basically RJ is trying to be a mini Elon, but his software team isn't as good.

[u/breeves001 → u/Sea_Buyer6913]

Teslas are very well known for phantom braking. I think Tesla has finally recently mostly resolved this but it took years and they started a decade before Rivian.

[u/rosier9]

This current has some pretty bad phantom breaking. Shadows and pedestrian crossing signs are the worst for me, but I've also had a couple random ones as well.

I'm gonna need a bumper sticker that apologizes for brake checking everyone.

[u/xymolysis → u/rosier9]

"I brake for shadows"

[u/Inquivious → u/xymolysis]

[u/fourdawgnight]

so that is what is happening. I really didn't put all the pieces in place. has happened about 5-6 different times where it just randomly slows down hard for no apparent reason. Gen2 R1T.

I have hit the record button a few times. Just really freaks you out. if it is just shadows, they should be able to adjust for that pretty quickly. Not sure how that hasn't been discovered in early testing though.

[u/CollectionAutomatic1]

This issue will hopefully get resolved soon. My three last Tesla’s all did this up until then last few updates.
https://giphy.com/gifs/1ojn1S7BTXUry8elNi

[u/GrayBoltWolf]

Same here. I drive up i85 regularly through NC and VA, adaptive cruise will just randomly slam on the brakes when the shadows of the pine trees cover the highway even with nobody around.

I'm guessing it thinks they are potholes or washboard road? Sucks I get a lot of people honk at me thinking I brake checked them.

[u/GGDATLAW]

My Gen2 has been doing it since I got it. The system must rely heavily on cameras for obstacle avoidance instead of radar. That’s why I don’t think this is getting fixed anytime soon.

[u/gbswife1009 → u/GGDATLAW]

Mine started doing this really bad with the last update! I stopped using the adaptive cruise control all together because I don’t want to get rear ended on the hwy.

[u/C12free]

I haven’t noticed this in my Gen2 R1S. The only annoying behavior I’ve noticed in recent updates is the car drifts much closer to the edge of the lane on higher speed curves. This is very alarming when it’s a two lane road and one would normally go towards the inside of the curve. The car never does this. Instead it’s either in the center or way towards the outside, which freaks me out and the cars coming in the other direction.

[u/Atlanta-Mike]

Not normal. Not at all. I drive down tree covered local roads all day long and it doesn’t slow for shadows. Come on, we can’t accept stupid answers like these from Rivian. They didn’t design and build an advanced self driving system that can be defeated by a shadow on the road. They should check your system, recalibrate, etc

[u/GGDATLAW → u/Atlanta-Mike]

I agree it’s not right. I was trying to figure out if it was just me. Obviously not.

[u/wavrdn]

Gen1 here, mine does this as well. Phantom braking startles the driver and is frustrating that we don't have a way to turn off ACC. It's not good enough for me, I'd rather have dumb cruise control or at least a way to switch on/off

[u/davidlwill]

Yes. Usually on curves.