BUG Unreliable speed limit displayed

[Halodde]

My car regularly displays the wrong speed limit on the dash. Often it won't pick up a sign and change when it should. And I get that. A little frustrating but really NBD. But yesterday and today, it has displayed Speed Limit 75 at times and there's not one sign on these roads that has ever said 75.

 

[joec]

My car regularly displays the wrong speed limit on the dash. Often it won't pick up a sign and change when it should. And I get that. A little frustrating but really NBD. But yesterday and today, it has displayed Speed Limit 75 at times and there's not one sign on these roads that has ever said 75.

That's very strange behavior. I'd have CS check that one out.

 

[idiot900]

I don't remember whether my car has ever shown a fictitious limit, but it's otherwise so unreliable as to be completely useless. But it's a feature I have zero interest in. I turned off the warnings and just ignore it.

 

[BobFM]

My car regularly displays the wrong speed limit on the dash. Often it won't pick up a sign and change when it should. And I get that. A little frustrating but really NBD. But yesterday and today, it has displayed Speed Limit 75 at times and there's not one sign on these roads that has ever said 75.

Quick question, were you coming off a highway that had a 75 mph speed limit? In some cases, I've seen my car still show a 30 mph speed limit when I'm getting on a nearby highway. It changes up to 60 mph the second it sees the speed limit sign, but that's a half mile up the road from that light.

If not the case, I agree with @joec and would contact CS...

 

[noobzilla]

I don't really use it. Just happen to see it because it's there.

Last week it showed 75mph in a residential area lol

 

[Halodde]

Quick question, were you coming off a highway that had a 75 mph speed limit? In some cases, I've seen my car still show a 30 mph speed limit when I'm getting on a nearby highway. It changes up to 60 mph the second it sees the speed limit sign, but that's a half mile up the road from that light.

If not the case, I agree with @joec and would contact CS...

Nope. There are not any 75 mph limit roads (or signs) in NYS.

 

[Tâm]

My car regularly displays the wrong speed limit on the dash. Often it won't pick up a sign and change when it should. And I get that. A little frustrating but really NBD. But yesterday and today, it has displayed Speed Limit 75 at times and there's not one sign on these roads that has ever said 75.

It's accurate at times and not at other times.

There might be some reasons such as 45 mph minimum highway speed sign, 35 mph for trucks only sign, 25 mph when children are present... but other times, there's no reason that I could find at other times.

It's an imperfect science for me right now.

 

[emoylv]

Quick question, were you coming off a highway that had a 75 mph speed limit? In some cases, I've seen my car still show a 30 mph speed limit when I'm getting on a nearby highway. It changes up to 60 mph the second it sees the speed limit sign, but that's a half mile up the road from that light.

If not the case, I agree with @joec and would contact CS...

This has been my experience as well. The Lucid seems to memorize the latest speed limit sign. IMO, it does this pretty well. Two problems that I've noticed: When going from a surface street onto an Interstate highway, its speed is governed by the last speed limit on the surface street. Oftentimes, I see myself at 35mph until the next speed limit posted on the Interstate so I have to jump on the pedal lest I get rear-ended. Conversely, when I exit, I'm at the Interstate speed limit until the Lucid "sees" the next sign. If I'm on cruise control, I have to pay attention. I've developed the habit of not engaging cruise control until I'm on the Interstate and disengage before I exit. I've also noticed that if you override the CC, it can get a little wonky until you quit stepping on the accelerator pedal. Not a big deal so far, but would be a big concern if/when DDPro kicks in with an autonomous capability.

 

[Mondo316]

The only issue I have seen is my Touring will show up a 20 mph school zone sign and show that until the next speed limit sign appears. I realize my car cannot know when school zones are active or not, so no big deal.

Regarding emoylv's engaging cruise control prior to merging onto the interstate, that is something I would never do. I never use cruise control in city driving, and I don't think it's designed to be used that way. I want to be in full control of my vehicle when merging on or off interstates.

 

[emoylv]

The only issue I have seen is my Touring will show up a 20 mph school zone sign and show that until the next speed limit sign appears. I realize my car cannot know when school zones are active or not, so no big deal.

Regarding emoylv's engaging cruise control prior to merging onto the interstate, that is something I would never do. I never use cruise control in city driving, and I don't think it's designed to be used that way. I want to be in full control of my vehicle when merging on or off interstates.

No, I don't engage CC until I'm on the interstate and I turn it off before I exit. Like you, I don't use it in city driving.

 

[philco]

I don't know whether the car is actually reading speed limit signs or getting the data from a GPS data base, but I suspect the latter. It is disconcerting to be driving down the interstate with the car displaying a 20 mph speed limit, especially when I haven't been on a road with a 20 mph limit (including school zones) recently. The problem is inconsistent, as I drive the same route every time and sometimes the car displays the correct limit and other times it doesn't. I would like to be able to rely on the displayed speed limit, but I've learned to ignore it.

 

[Volund]

I don't know whether the car is actually reading speed limit signs or getting the data from a GPS data base, but I suspect the latter. It is disconcerting to be driving down the interstate with the car displaying a 20 mph speed limit, especially when I haven't been on a road with a 20 mph limit (including school zones) recently. The problem is inconsistent, as I drive the same route every time and sometimes the car displays the correct limit and other times it doesn't. I would like to be able to rely on the displayed speed limit, but I've learned to ignore it.

I was told by the techs that it is pulling the speed limit signs from the DOT database

 

[Halodde]

I was told by the techs that it is pulling the speed limit signs from the DOT database

It's not reading the actual speed limit signs via the camera behind the rear view mirror?

 

[borski]

I don't know whether the car is actually reading speed limit signs or getting the data from a GPS data base, but I suspect the latter. It is disconcerting to be driving down the interstate with the car displaying a 20 mph speed limit, especially when I haven't been on a road with a 20 mph limit (including school zones) recently. The problem is inconsistent, as I drive the same route every time and sometimes the car displays the correct limit and other times it doesn't. I would like to be able to rely on the displayed speed limit, but I've learned to ignore it.

It’s reading the signs, same as Tesla does. That’s why both screw up sometimes. When I first got the car, it read every “speed limit for trucks” sign, which was infuriating.

They may have switched it to using a database since then; not sure.

 

[idiot900]

I haven't done any kind of proper test but it seems that

1. The displayed speed limit changes the instant I pass a speed limit sign (when it works)
2. When I turn onto a new road without a speed limit sign in view, the speed limit display doesn't update, as it should if it were drawing from a database
3. It misses signs often enough that I simply don't trust it
4. Who cares, I'm looking at the road and reading the signs myself

 

[emoylv]

I haven't done any kind of proper test but it seems that

1. The displayed speed limit changes the instant I pass a speed limit sign (when it works)
2. When I turn onto a new road without a speed limit sign in view, the speed limit display doesn't update, as it should if it were drawing from a database
3. It misses signs often enough that I simply don't trust it
4. Who cares, I'm looking at the road and reading the signs myself

This has been my experience as well. When I pass a temporary 55mph sign on the highway, the car instantly reports and asks if I want to set the cruise to the new limit.

 

[DeaneG]

I haven't done any kind of proper test but it seems that

1. The displayed speed limit changes the instant I pass a speed limit sign (when it works)
2. When I turn onto a new road without a speed limit sign in view, the speed limit display doesn't update, as it should if it were drawing from a database
3. It misses signs often enough that I simply don't trust it
4. Who cares, I'm looking at the road and reading the signs myself

Agreed. FWIW our Volvo EV reads signs and acts very similarly to the Air.

 

[Steveinarizona]

My car regularly displays the wrong speed limit on the dash. Often it won't pick up a sign and change when it should. And I get that. A little frustrating but really NBD. But yesterday and today, it has displayed Speed Limit 75 at times and there's not one sign on these roads that has ever said 75.

Aspirational

 

[joec]

CarPlay gives me Speed Limit data. So I always double check that against what I see from Lucid. I find it works here in CO most of the time. But it does miss occasionally.

 

[donfenn]

Yesterday for about 10 miles on the 405 in L.A. my speed limit read 35 MPH... suddenly it corrected itself to correct limit, but wondering how this works?