I never knew the speed limit recognition was so bad

[Rolfe]

I started disabling the speed limit recognition on my car on day 2, along with the LKA, because the LKA was frankly diabolical and the speed limit thing was obviously lying to me. I kept doing that until I got the LKA fix last week, when I decided to discontinue the pre-flight routine to see what would happen.

I knew the speed limit recognition was poor on the A701, because almost all "national speed limit" signs are followed soon afterwards by a reminder that the HGV speed limit is 40 mph, so the car sees that and flashes 40 at you for the next 20 miles. But I've seen it behaving really badly on most roads I've been on recently. It seems not to notice the national speed limit sign when leaving villages quite a lot of the time, so that it's flashing 30 or even 20 at me for miles. I've seen it flashing 30 or 20 when I've been on the motorway and I have no idea where that came from. It also cancels itself any time I turn a corner or even go round a roundabout (or even, on one occasion, just drew into a layby then drove on), even when the speed limit hasn't changed, and stays showing three lines until it happens to see another sign.

Is this typical, or is mine faulty in some way?

 

[TerryN]

Mine is much the same. I thought it was because I haven't had any updates applied (yet). Even when it does see national speed limit signs that means 60mph so no good on the motorway. Also on the motorway it often spots the 30mph sign on the slip roads as I go past.

As an aside I have recently noticed that it does recognize other signs like the blue motorway sign. When it sees this it switches to 70mph with the 3 dots underneath. I wonder if there are other signs it does it's own interpretation for.

 

[siteguru]

Ditto with mine ... Sign detection is sporadic; it's certainly not good enough to use for an auto-speed-limiter. However when mine does see a NSL sign it now reverts to the 3 dashes rather than flash 60 at me when on a 70 NSL road.

 

[webhiker]

As already said, yes it crap. Save your senses, worry no more about it. You don't even need to turn it off, just ignore it.

 

[Rolfe]

Ditto with mine ... Sign detection is sporadic; it's certainly not good enough to use for an auto-speed-limiter. However when mine does see a NSL sign it now reverts to the 3 dashes rather than flash 60 at me when on a 70 NSL road.

Mine doesn't do that. It flashes at me when I'm doing more than 60 on a dual carriageway. How would it know, anyway? (I think you're probably seeing the three dashes for a different reason.)

As already said, yes it crap. Save your senses, worry no more about it. You don't even need to turn it off, just ignore it.

I find it annoying. I think I'm going to turn it off. (And I'll probably turn off LKA while I'm at it because although it is no longer trying to rip the steering wheel out of my hand, I don't sense that it's actually doing any good.)

 

[webhiker]

Mine doesn't do that. It flashes at me when I'm doing more than 60 on a dual carriageway. How would it know, anyway? (I think you're probably seeing the three dashes for a different reason.)



I find it annoying. I think I'm going to turn it off. (And I'll probably turn off LKA while I'm at it because although it is no longer trying to rip the steering wheel out of my hand, I don't sense that it's actually doing any good.)

It's a matter of you feeling good about being annoyed or not. I just ignore what I don't like. I don't bother turning off sign recon or LKA. the bad they are doing is less than the conscious effort of (remembering) to turn them off.
But you are right, neither is doing any good to me

 

[siteguru]

Mine doesn't do that. It flashes at me when I'm doing more than 60 on a dual carriageway. How would it know, anyway? (I think you're probably seeing the three dashes for a different reason.)

No, I 100% guarantee that every time I pass a NSL sign (and the car has seen it) the 3 dashes now appear rather than 60. Every. Single. Time. So it's a change by design IMO.

Perhaps this was another update unrelated to SC077, and my car just happened to get it at the same time whilst yours didn't.

 

[Rolfe]

Very odd. When I pass an NSL sign I get this on the driver's screen.

And if I exceed 60 mph then that will flash, even if I'm on a dual carriageway. It's very annoying. I may inquire about getting this seen to at a future date, if you have a fix.

 

[Ferretusmaximus]

Agree with all the above. The most annoying feature is travelling the length of the M4 at 60mph with the delimited sign displayed on the driver's screen and it flashing for the whole journey - suspect the system was never tested in this country and, as seems the norm now, the manufacturer waits for the customers to test their systems for them.

 

[Rolfe]

I was a bit concerned that even if the LKA was acceptable, I would still have to do the pre-flight routine because of the speed limit thing. It looks as if that's going to be the case, and I might as well turn off the LKA while I'm at it for all the benefit it offers. The main advantage now is that if I forget to turn off the LKA I'm not going to get the fright of my life at the first bend.

 

[NLMGSAN]

And now you have the mandatory isa system in the cars after june 2024....

I always disable it. And even after the update it causes to many stupid errors and it freaks out ACC. Only alert mode doesn't. As before the update. So I always change to Alert, but with the irritating beep off.

 

[pjmmk]

I disable speed limit recognition and LKA every time I get in the car.
LKA because I don't like the vibration, feels to me like something's about to break.
Speed limit recognition because it's completely useless. It has no concept of the national speed limit, it thinks dual carriageways are 60 (should be 70), single carriageways are 40 (should be 60) and 30's are all over the place, sometimes 20, sometimes 30. It's hardly ever correct.
On the other hand, Waze gets it right nearly all the time so it can be done.

 

[Kithmo]

Sign recognition has been rubbish in each car I've had it in, the Prius was the same, I'm just glad it doesn't actually limit the car's speed to match the signs.

 

[Rolfe]

It better not. Miles on the motorway the other day with 30 flashing at me. No idea why. More miles on the A721 with either 20 or 30 flashing, because I don't think the car saw the national speed limit sign at the end of a couple of villages. And the notorious A701 where every national speed limit sign is shortly followed by this.

They need to sort this out comprehensively before that feature will ever be usable.

 

[Kenp1]

I don't bother turning either off. I don't notice the sign recognition, so couldn't even tell you what it was doing, and the LKA was set to it's lowest sensitivity when I got the car and very rarely kicks in.

 

[pjmmk]

Whether LKA is useful or not really depends on the sorts of roads you're driving on. Where I usually drive, the roads are almost all national speed limit single and dual carriageways and you are forced to get close to the lines in order to avoid potholes, etc. LKA is nothing more than a nuisance as far as I'm concerned. I could see it being useful on a long boring trip on a motorway or something like that, but my car has never actually seen one!

 

[Vaasref]

LKA is a major system to improve stafety.

It is a highly sofisticated system that forces you to actually always be focusing on the road. If you fail to be in complete control of your vehicle it will remove you from the road by autonomously storing the car in the closest ditch.

 

[Anon70]

I have only had traffic sign recognition on the MG4 and my previous car a Mini Clubman. On both cars there were many issues with the system including:
The system being driven by POI data points in the sat nav that were not updated with the maps
20mph signs being too small to be recognised by the camera
Picking up speed limit signs from side roads
Not recognising changed speed limits unless they were clearly signposted multiple times
The display updates after you pass the speed limit sign not as you approach


All of which means for me the system is next to useless 99% of the time

 

[DixieTGS]

Any system that relies on a camera only is going to get it wrong much of the time. However I'd be quite happy if it just displayed the last sign it saw, perhaps flashing for a few seconds on each change. That would actually be both useful and not annoying for me.

 

[gDallasK]

Sign recognition has been rubbish in each car I've had it in, the Prius was the same, I'm just glad it doesn't actually limit the car's speed to match the signs.

It worked perfectly in the Jaguar E-Pace which preceded my current MG4. So it can't be rocket science!