ACC not calculating speed with a mobile speed camera

[London1910]

Hi there reaching out to the community.

I had a strange issue. On Sunday I was driving up the A1 north of Beeston - I use the ACC on the ID3 (8 weeks old) and it correctly approximates the speed at every road without fail. However I found an odd issue. On the A1 there is roadworks reducing speed to 40 which the car correctly understands however about 200 meters before a Carnell mobile speed camera the car detects 60 and speeds up towards the camera so you have to override (by which point you are speeding and hoping you have not got a ticket) as without traffic the car is at 40. Straight after the camera 40 is detected. Doing 200 miles up and down the A1 I did not encounter this issue I also tried it further 2 times (after detection immedietly breaking) and this did it exactly the same.

I have reached out to VW to try to understand what’s causing this and they don’t want to know.

I have two theories on what might be causing this bith could be totally wrong.

1) that the route information that ACC has been somehow entered into the database incorrectly for the speed camera (understanding how and who updates this would be useful) - causing the ACC to have the actual road speed rather than modified
2) that the camera on the ID3 observes the mobile camera and the software prioritises this speed for the road rather than route information

Obviously would be nice to understand what causes this and if this is a general issue with mobile cameras when placed in roadworks or this is a one off as the car deciding to speed towards a speed camera is not ideal !

[London1910]

I managed to find this which was really useful and also checked again. It seems that the 40mph was picked up by a road sign as you see that sign in the ACC but the 60 there is no sign it just displays ‘is detected’ suggesting this is route information and or the camera is aware of speed cameras and there is some weird logic here.

- The Camera also "read's" speed signs (in the UK / Europe these are in a standard red circle - so I guess easy for the Camera / ACC system to read), the car identifies the speed and adjusts the speed accordingly, particularly in temporary speed limit areas, which the sat-nav database may not know about.

- The "camera sign read" - has priority over the sat nav speed database.

- It's also worth mentioning, when there are road-works signs (which are a standard red triangle with person digging in the UK / Europe), the car recognises it and puts an appropriate warning on the display.

[smyth1492]

Unfortunately ACC is not perfect yet and you have to remain aware of these little things happening. In my experience they tend to reoccur in the same locations so at least you will become ready for when its going to happen if using a road frequently.

Mine sometimes slows the car down because it things I have taken the slip road on a dual carriageway or motorway and often, more on the continent due to sign placement in France, the car reads the speed sign in the slip road and starts to slow you down even though you are still on the main road.

I think it is next year in Europe that all cars by law need to be able read road signs and adapt the speed, I do think the system is flawed but I ham living with it as in general the advantages outweigh the small issues

[Scratch]

Unfortunately ACC is not perfect yet and you have to remain aware of these little things happening. In my experience they tend to reoccur in the same locations so at least you will become ready for when its going to happen if using a road frequently.

Mine sometimes slows the car down because it things I have taken the slip road on a dual carriageway or motorway and often, more on the continent due to sign placement in France, the car reads the speed sign in the slip road and starts to slow you down even though you are still on the main road.

I think it is next year in Europe that all cars by law need to be able read road signs and adapt the speed, I do think the system is flawed but I ham living with it as in general the advantages outweigh the small issues

" think it is next year in Europe that all cars by law need to be able read road signs and adapt the speed"
Really???? ALL cars? Retrospective? Surely not?

[roybosh]

Driving north over the Queensferry Crossing and up the M90 my car sees a 40 zone and drops from 70.
It doesn't revert to 70 until near Kinross, maybe 10 miles up the road. It's happened both times I've driven this road with ACC on. No temporary limits were evident.
I did think the car might have seen a 40mph sign on the off ramp from the M90 near the park and ride at the Rosyth/Inverkeithing exits or a sign on one of the roads running under the M90, but I can't be sure.
I'll pay attention next time I'm on that part of the road

[chrisfs]

Driving north over the Queensferry Crossing and up the M90 my car sees a 40 zone and drops from 70.
It doesn't revert to 70 until near Kinross, maybe 10 miles up the road. It's happened both times I've driven this road with ACC on. No temporary limits were evident.
I did think the car might have seen a 40mph sign on the off ramp from the M90 near the park and ride at the Rosyth/Inverkeithing exits or a sign on one of the roads running under the M90, but I can't be sure.
I'll pay attention next time I'm on that part of the road

The same thing happens if you leave the M25 northbound to join the M40 westbound. For many miles the car thinks the limit is 60mph. I’ve learned to manually override the ACC speed to reset to 70 until it eventually catches up.

Generally though the ACC is a great feature of the car.

[London1910]

Thanks …I got a response from the police and raised this with VW. My belief is still it didn’t get this from the road side signs as no sign notification comes up so this must be from the route information which the national highways supply’s to a central DB and this data was wrong. So the fault is not with ACC but the data in my opinion. But I’ll see what I can find out.

[sidehaas]

In the context of the OP, it is worth adding for the unaware that the ID3 is unreliable at reading speed limit signs on overhead gantries, of the type you now often get on motorways. Sometimes it will see them but more often it won't. It's only reliable at reading normal roadside signs.

[London1910]

Just want to state really thankful for the responses and input much appreciated your time

[smyth1492]

Unfortunately ACC is not perfect yet and you have to remain aware of these little things happening. In my experience they tend to reoccur in the same locations so at least you will become ready for when its going to happen if using a road frequently.

Mine sometimes slows the car down because it things I have taken the slip road on a dual carriageway or motorway and often, more on the continent due to sign placement in France, the car reads the speed sign in the slip road and starts to slow you down even though you are still on the main road.

I think it is next year in Europe that all cars by law need to be able read road signs and adapt the speed, I do think the system is flawed but I ham living with it as in general the advantages outweigh the small issues

" think it is next year in Europe that all cars by law need to be able read road signs and adapt the speed"
Really???? ALL cars? Retrospective? Surely not?

All new cars - sorry

[Scratch]

Unfortunately ACC is not perfect yet and you have to remain aware of these little things happening. In my experience they tend to reoccur in the same locations so at least you will become ready for when its going to happen if using a road frequently.

Mine sometimes slows the car down because it things I have taken the slip road on a dual carriageway or motorway and often, more on the continent due to sign placement in France, the car reads the speed sign in the slip road and starts to slow you down even though you are still on the main road.

I think it is next year in Europe that all cars by law need to be able read road signs and adapt the speed, I do think the system is flawed but I ham living with it as in general the advantages outweigh the small issues

" think it is next year in Europe that all cars by law need to be able read road signs and adapt the speed"
Really???? ALL cars? Retrospective? Surely not?

All new cars - sorry

That's ok. I just wondered. Mind you, even if all new cars have these systems, you don't have to use it. Or are they making that compulsory as well?

[TimF]

Since our car was updated to 2.4, it has a tendency to think that something other than a proper speed limit sign has been detected. There's a rural 40mph road nearby where, as we pass side roads, the car claims to detect a 30 limit. There's no such sign in the side roads or anywhere near the junctions. Conversely, it WILL detect limit signs on motorway slip roads and on adjacent roads and claim the motorway is no longer 70mph limit.

[G43FAN]

If it's the same place every time it will be from the GPS data, the car uses multiple sources for the info. There is a URL somewhere to let you report issues, but I reported an issue near here and nothing ever happened. (30mph was extended as for about 1/2 mile it went 30 - 60 - 50) they removed the 60 section but the car still speeds up as it passes the old posts which are still there minus National signs. Was changed 5+ years ago.

Surprised you got a response from the Police, the car is not Automated, you are in control at all times. (unless that was their response).

From previous discussions, I believe the data is obtained from here.. https://mapcreator.here.com/ and you can submit corrections (as I say, I wasn't very successful)

[roybosh]

Driving north over the Queensferry Crossing and up the M90 my car sees a 40 zone and drops from 70.
It doesn't revert to 70 until near Kinross, maybe 10 miles up the road. It's happened both times I've driven this road with ACC on. No temporary limits were evident.
I did think the car might have seen a 40mph sign on the off ramp from the M90 near the park and ride at the Rosyth/Inverkeithing exits or a sign on one of the roads running under the M90, but I can't be sure.
I'll pay attention next time I'm on that part of the road

Ha, mystery solved.

Today, returning from Edinburgh, I drove on the northbound carriageway on the M90 over the Queensferry crossing, I spotted a temporary 40mph sigh that had been left leaning against the central reservation. It's one of those that is like an A frame. As the car didn't see any 'end of restrictions' signs it thought it was 40mph for miles.
Technology eh!!

[LonnyLonLon]

As with all modern tech there are going to be issues and with ACC and speed you have to be especially alert.

The reason I say this?

1) Near us a 40mph has been lowered to 20. So I do 20 but as the car approaches a bend the ACC says “sharp bend” and drops the speed to 16mph. However, as soon as we go past the bend the speed goes up to 40 until it sees a 20 repeater sign at which point it drops back down to 20. As this is repeatable I suspect the sharp bend drops the ACC back to GPS mode.

2) While on the motorway with the ACC set to 60mph, I went past a foreign lorry doing 56mph. The next thing I know the ACC has a new target speed of 100!!! I suspect what happened here was the cars camera saw the 100km/h sticker on the rear of the lorry and acted on that.

Luckily I was awake so could quickly override the ACC but it’s really something that should be on the (software) engineers to-do list.

[sidehaas]

You have to be alert to what the ACC is doing and ready to cancel it immediately if it does something silly. That's why these systems are still a long way from autonomous driving. Lots of investment is certainly going in to these systems' development but the issues exist for many cars at the moment - the problems are caused by fundamental shortfalls rather than bugs. Such as, what to do about a 40mph sign that's been left lying by the side of the road, or a 100kph sign on the back of a lorry. No straightforward visual system will ever be able to deal with these things, it has to be able to constantly understand the context and make intelligent decisions, which is a level beyond visual recognition.
In case it's not clear, if you don't like the smart functions you can easily turn them off in the Assist menu so that you just have a "normal" ACC system in the ID3.

[Midgex]

than I do, I think.

Between us, even fewer than either.

[TimF]

As with other aspects of this car and - it seems - many other cars, the various sub-systems can be very good at recognising things (eg speed limit signs), but very poor at incorporating that properly into a full "awareness" of the road situation when it comes to controlling the car's speed. Same with impending collision detection (which doesn't understand that flowers drooping over a drive are not an obstruction), same with lane-keeping. Each time a sensor or sub-system is improved or has features added, this offers potential for improving overall safety, comfort, convenience etc. But it also increases the system complexity and opportunities for unexpected outcomes of low-probability situations.

And, of course, the more elaborate a system becomes, the longer it takes to test thoroughly, to the point where it becomes almost certain that it will be commercially released as passing all tests and checks, but once in use by millions of people in thousands of millions of specific situations, it behaves in unexpected ways.