Road speed signs display

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Ruby12345#
Posts: 95
Joined: Wed Dec 13, 2023 9:17 pm

Post by Ruby12345# »

Never seen it before but this morning had the National speed limit sign come up on dash, was only displayed for a few seconds then went off it was then blank showing no speed limit..Yet when it reads a speed limit 30-40 etc it stays displayed on the dash..Is this something new or something I haven’t noticed before..

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Alexandrovich
Posts: 31
Joined: Wed Aug 25, 2021 3:12 pm

Post by Alexandrovich »

I've had this happen to me, and thought it may be when the road sign has not been read properly because it may have been partly obscured, and the vehicle then displays the symbol for national speed limit based on location. Just a guess, and didn't appear to interfere with displaying properly on other occasions.
Volvo XC40 T4 MY20 FWD Inscription Pro, Onyx Black, Blond interior, Winter Pack, Tempra Spare, Privacy Glass, Mudflaps, Dashcam and Reversing Camera. AutoGlym LifeShine.
Itsme
Posts: 37
Joined: Mon Jul 03, 2023 9:02 pm

Post by Itsme »

Whilst I can't help with the OP's original question, I can say that my cars recognition of road side speed signs and the actual speed limits is less than perfect.

For example one of the local roads had the speed limit reduced to thirty MPH, the change took place about two years ago. The road signage displays 30 MPH at the beginning of the reduced speed limit, my car displays the 30 MPH speed limit as I approach/pass the sign.
Then after about one hundred yards further on the car display reverts to the previous speed limit on the road of 40MPH.

Another example on a local road when leaving a 30MPH area going on to a national speed limit (and signed appropriately) road, 25 yards beyond this national speed limit sign and at a roundabout, my car then displays 30 MPH disregarding the previous speed limit signage. In this case the road I've joined is a dual carriage way with no other restricted speed limit signage!

I suspect this has something to do with Googles mapping data for the area which hasn't been updated to reflect the historic change in either speed limits or road layouts.
Peter
XC40 Mild Hybrid (Early2023)
Exmpa
Posts: 19
Joined: Sat Nov 06, 2021 7:33 pm

Post by Exmpa »

I have a Sensus driven system and have occasionally seen the National Speed Limit sign but it has been infrequent and caused no issues. In general the reading of signs is consistent and glitches few and far between. However that only applies to the normal function, on the occasions I have selected the Automatic Speed Limit (ASL) function I have noted some quite erratic indications with markedly different indications on roads where the advisory system functions correctly. I’ve no idea why, other than the algorithm used by ASL might differ in some ways.

The only real glaring error I have encountered was the time it advised me that the speed limit in Tesco’s car park was 120kph. That didn’t seem right!

exmpa
Imac
Posts: 13
Joined: Wed Aug 30, 2023 8:57 am

Post by Imac »

I have seen it once when going from a 30mph to 60mph. it flashed up for a second and then went to 60.
2023 XC40 B4 Plus Dark AWD Auto and Volvo Towbar.
UncJ
Posts: 11
Joined: Wed Apr 10, 2024 11:25 pm

Post by UncJ »

Had it quite a few times over the years using Sensus to be fair. Happened last about a week ago on the M5.
Ruby12345#
Posts: 95
Joined: Wed Dec 13, 2023 9:17 pm

Post by Ruby12345# »

Imac wrote: Mon Apr 15, 2024 7:59 pm I have seen it once when going from a 30mph to 60mph. it flashed up for a second and then went to 60.
It happened the morning going south the sign flashed up but then showed no speed.. Now on the same stretch of road going north went past a National speed limit sign it flashed up and went to 60 mph..work that one out.. I drive this stretch of road going to work every day, yet only today it happened.
RonFleet
Posts: 154
Joined: Sun Aug 16, 2020 4:48 pm
Location: Hampshire

Post by RonFleet »

In my car, the speed limit sign recognition is worse than useless. The car tells me the wrong speed limit as often as it does the correct limit. I've had 70mph show in a 30mph road, 20mph in a 60mph limit and everything in between. I no longer trust it.
Cheers,
Ron

XC40 B3 Plus Automatic
Fjord Blue
Cevoli21
Posts: 308
Joined: Sun Dec 05, 2021 8:38 am

Post by Cevoli21 »

Completely agree. Speed limit signs are hopeless. However it's not just Volvo. Our sons Ioniq 5 makes has the same errors as the Volvo. It appears it's not just the camera getting confused but also the underlying database. Doesn't bode well for full autonomous driving.
XC40 P8 Twin Motor Pro in Denim Blue with Tow bar, mudflaps
RonFleet
Posts: 154
Joined: Sun Aug 16, 2020 4:48 pm
Location: Hampshire

Post by RonFleet »

Well said!
Cheers,
Ron

XC40 B3 Plus Automatic
Fjord Blue
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