Where does it get speed limits?

[TravisR100]

2026 Gen 2 R1T. Where does it get the speed limits from? I assumed it read the signs but I can tell it's obviously not doing so. I routinely pass speed limit signs on several routes I normally drive and the speed limit definitely doesn't update when I pass them. On some it doesn't update within 5 minutes of passing them.

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[Donald Stanfield]

It used to read the street signs; you could always tell when you passed one. Now I think it shakes a magic 8-ball.

 

[TravisR100]

I agree on the magic 8 ball. Doesn't seem to be any rhyme or reason to it and it's frequently wrong.

 

[VandalSibs]

Some of it comes from map data that is downloaded to the vehicle once in a blue moon, some of it is from the camera.

 

[Dark-Fx]

Reads signs but falls back to map data quickly.

 

[JacobAZ]

It's in the map data. Does not actually read speed signs. For example, the speed limit on 260 going into Payson AZ was 45. They lowered the speed and swapped out the 45 for a 35 sign, same spot. Took months before, the map software was updated and consequently months for speed to change in RIvian (and Tesla) display.

 

[godfodder0901]

It's in the map data. Does not actually read speed signs. For example, the speed limit on 260 going into Payson AZ was 45. They lowered the speed and swapped out the 45 for a 35 sign, same spot. Took months before, the map software was updated and consequently months for speed to change in RIvian (and Tesla) display.

Yes, it does read the signs as covered on this forum dozens of times. Does it do it for every road or sign? No. Is it the primary source? Who knows. Does it read speed limit signs? Absolutely, without question and provably.

 

[portdirect]

As long as it keeps thinking the highway near me is 85mph I'm happy.

This is one of the things mobileye is/was really good at - I think now (gen2) it's mostly relying on map data and using camera's when it can.

 

[BCondrey]

I asked RA about this. I was on a beach highway and the truck was reading the signs as 35, but would then change back to 45 a bit later. Kept happening. RA said the vehicles will "read" speed limit signs AND use recent map data to determine the speed limit. This can cause issues for roads that have seasonal changes in speed limits. The road I was on lowers the speed limit during the summer, raises it in the off-season. I've also observed that gen1 cameras aren't always great at reading signs. Like the ones that have flashing lights around them or the electronic signs.

 

[JeffnReno]

I can imagine explaining to a patrol officer that the car said it was 50 mph in that 15 mph school zone. Even FSD in Tesla still needs supervision or accept the consequences. I have noticed that some areas in our Tesla seem to read signs and others don't but if I see the sign, I adjust accordingly. The Rivian will probably be the same for some time so I accept it as Driver assist features only. Still a good question for discussion by the OP.

 

[Greg Chick]

As long as it keeps thinking the highway near me is 85mph I'm happy.

This is one of the things mobileye is/was really good at - I think now (gen2) it's mostly relying on map data and using camera's when it can.

My dash says the limit is 85 mph on Hwy 58 decending the grade out of Tehachapi Ca. this has not changed for 3 yrs. It does correct a few miles down the grade getting into the Central valley. My guess is that the cell signal there is out and the default is 85? Or a DOS Typo?

 

[Greg Chick]

I can imagine explaining to a patrol officer that the car said it was 50 mph in that 15 mph school zone. Even FSD in Tesla still needs supervision or accept the consequences. I have noticed that some areas in our Tesla seem to read signs and others don't but if I see the sign, I adjust accordingly. The Rivian will probably be the same for some time so I accept it as Driver assist features only. Still a good question for discussion by the OP.

I have had mine in cruze when set to speed limit and had it attempt to do 85. I reset it and drive happily down the hill.

 

[loqueid]

Our Honda Accord reads a 35mph as 100mph. I wish it would do that in the Rivian. zzzzOOOOOOOOOMMMMMMMM

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