ACC on Smart Motorways

[Goaty]

Indeed, just to put a bit more context against what I wrote above: it doesn’t brake excessively if it reads the wrong sign and tries to slow to 50 or even 30 on a 70mph road. It does it ‘gently but productively’ if that makes sense. I think it does activate the brake lights though, as I’ve had a muppet travelling too close to me, flash their lights at me when my Enyaq started to slow down for, as far as they were concerned, no obvious reason.

I do now just set the speed myself and then let ACC do what it’s really good at (preventing me from exceeding the speed I set, and preventing me from getting too close to the vehicle in front).

[TimP]

Hi
I encountered this issue with ACC on the M6 around Stoke yesterday. The smart motorway gantry signs were switched off but the car suddenly decided we were entering a 50 zone and braked, a little later it changed back to 70. This happened at least twice and definitely correlated with passing the blank overhead signs. Bizarrely the warning sign for deer crossing also briefly flashed up on the display and the map a couple of times as we passed a gantry. It’s quite disconcerting. In general I have found the ACC sign detection pretty reliable and a very useful driving aid. I am wondering whether the camera perhaps sees a little outside the visible spectrum and misreads reflections off the LED display lamps. Otherwise I am a very satisfied owner of an Enyaq iv80 2022 model

[Ken3966]

I also turn off the automatic slowing for bends, roundabouts, junctions etc. it is far too conservative such as dropping to 35 for a bend easily taken at 50 when acc set to 50 or slowing down on approaching roundabout so early you instinctively touch the accelerator to speed up again to the desired braking point.
Acc without speed limit response and hazard response is fantastic though and makes the car so easy to drive. I just set it to speed limit and then know I can’t be caught out by mistake as so easy to go over inadvertently.
So easy to quickly change with the 5mph increments up and down on stalk.

[CrowSysE243]

Hi
I encountered this issue with ACC on the M6 around Stoke yesterday. The smart motorway gantry signs were switched off but the car suddenly decided we were entering a 50 zone and braked, a little later it changed back to 70. This happened at least twice and definitely correlated with passing the blank overhead signs. Bizarrely the warning sign for deer crossing also briefly flashed up on the display and the map a couple of times as we passed a gantry. It’s quite disconcerting. In general I have found the ACC sign detection pretty reliable and a very useful driving aid. I am wondering whether the camera perhaps sees a little outside the visible spectrum and misreads reflections off the LED display lamps. Otherwise I am a very satisfied owner of an Enyaq iv80 2022 model

I experienced the same behaviour on the M4 going in to London recently. The areas where it changed to 50 were those where there had been a 50 speed limit before the "Smart" motorway works completed. As the speed limits used are derived from the map data and then modified by any signs that have been detected, this will be because map speed limit data have not been corrected since the roadworks completed. Our Kona also shows the speed limit changes at the same places, although this is not linked to the ACC. The M6 past Stoke had 50 limits through roadworks relatively recently.

I have found that the recognition of speed limit signs is pretty good on the Enyaq. There is a stretch of the M4 where the Kona read matrix signs set at 30 or 60 as being 80 due to the font used! It also occurred on the motorway near Belfast (I cannot remember whether it was the M1 or M2 at the time we experienced it). The more commonly used font did not cause the problem. When we went on the same stretch of M4 with the matrix set to 60 the Enyaq read it correctly.

I don't mind the ACC slowing down when it thinks the speed limit has reduced as it is easy to over-ride, however I am less keen on it increasing speed, particularly as I normally go at 60 to 65 when the limit is 70. Once I have a bit more experience with it I will decide whether to turn off the speed limit adjustment and revert to the behaviour of the Tiguan and Kona.

[TimP]

That sounds a very reasonable explanation thanks. Hopefully it will be sorted out as maps are updated. The deer crossing alert remains a bit of a mystery! As others have remarked Enyaq ACC is overall very effective and reliable. I have learned that it will safely slow you down in stop start motorway traffic jams, it’s even pretty good at coping with those people who like to cut in to the safe gap ACC has left between you and the car in front. The ability to fine tune that gap to your own preference is useful too.

[Choppsie]

Hi
I encountered this issue with ACC on the M6 around Stoke yesterday. The smart motorway gantry signs were switched off but the car suddenly decided we were entering a 50 zone and braked, a little later it changed back to 70. This happened at least twice and definitely correlated with passing the blank overhead signs. Bizarrely the warning sign for deer crossing also briefly flashed up on the display and the map a couple of times as we passed a gantry. It’s quite disconcerting. In general I have found the ACC sign detection pretty reliable and a very useful driving aid. I am wondering whether the camera perhaps sees a little outside the visible spectrum and misreads reflections off the LED display lamps. Otherwise I am a very satisfied owner of an Enyaq iv80 2022 model

I experienced the same behaviour on the M4 going in to London recently. The areas where it changed to 50 were those where there had been a 50 speed limit before the "Smart" motorway works completed. As the speed limits used are derived from the map data and then modified by any signs that have been detected, this will be because map speed limit data have not been corrected since the roadworks completed. Our Kona also shows the speed limit changes at the same places, although this is not linked to the ACC. The M6 past Stoke had 50 limits through roadworks relatively recently.

I have found that the recognition of speed limit signs is pretty good on the Enyaq. There is a stretch of the M4 where the Kona read matrix signs set at 30 or 60 as being 80 due to the font used! It also occurred on the motorway near Belfast (I cannot remember whether it was the M1 or M2 at the time we experienced it). The more commonly used font did not cause the problem. When we went on the same stretch of M4 with the matrix set to 60 the Enyaq read it correctly.

I don't mind the ACC slowing down when it thinks the speed limit has reduced as it is easy to over-ride, however I am less keen on it increasing speed, particularly as I normally go at 60 to 65 when the limit is 70. Once I have a bit more experience with it I will decide whether to turn off the speed limit adjustment and revert to the behaviour of the Tiguan and Kona.

I commute the M4 smart motorway from the A4 to the A33 and I haven't had that problem, the car tries to maintain 70 where possible but as some will know, a lot of drivers seem to slow to 60 along there. It does obey the signs if visible but uses sat nav speeds, no problem at all

[CrowSysE243]

That's interesting. The Enyaq has done it twice now, and the Kona three times, east bound on the stretch passing where the works area used to be between junction 10 and 8/9. Each time I was doing between 60 and 65 but always in lane 1. It is possible that the car is using the limit that was on the, no longer present, slip road into the works area, due to the uncertainty about the GPS position. The speed limit indication increased again once I was past where the on slip had been. I cannot remember exactly where the speed limit was reduced again nearer London, other than it was one of the areas where the roadwork speed limits were removed fairly late and it was around Slough. It is possible that it was picking up map speed for an adjacent road. I will have to experiment the next few times I am along that route. I did not experience it west bound because I came back a different route.