From the detail in the story it appears that the car won’t automatically reduce power:
“After lobbying from car manufacturers, the EU softened initial plans to make the more stringent ISA system, which cuts engine power once the speed limit has been reached, mandatory. Such a system, which can be overridden for a brief time by a driver pushing hard on the accelerator, has been shown to reduce road deaths by up to 20 per cent.”
Of course that is only slightly mitigating the issues caused by the changes. If I’m doing 70 and I’m briefly allowed to hit the accelerator when it thinks the limit is 30 it will eventually slow down to a crawl on the motorway
Do you assume that the system will read the speed limit sign incorrectly or are you suggesting that, if and where it exists, a 30 mph limit on motorways doesn’t need following?
If I understand it correctly, car manufacturers are now being giving the option to only implement an advisory system (which can be ignored by the driver). Let’s have a guess which one most of them will go for.
I am talking about the frequent occasions when the speed limiter is wrong. These situations are very common and a limiter would be dangerous.
You are correct the speed limiter can be advisory on the car manufacturers decision, but for European cars they will be compulsory. If the UK market cars are euro cars with the compulsory bit switched off there is an obvious gap that encourages EU drivers to use the same switch off. The EU won’t like that so they will be compulsory with no software disabling allowed OR you might not be allowed to drive your car into the EU
Besides, I’m not sure the point of an advisory speed indicator - I’ve got one - it’s called a speedo.
Of course in some ways this doesn’t worry me, my car doesn’t have the speed limiter and the next car I buy might well be self drive anyway (won’t be getting a new one for 3-4 years) and they will be limited
There’s an interesting line in the link you posted:
The new automatic detection software spots walkers, cyclists and vulnerable road users.
This implies the same camera tech that ‘reads’ the signs will also have some sort of collision avoidance software. That’s great news for everyone on the outside of the giant steel cages 
Seems to be already implemented in some high end cars, but hopefully this becomes mandatory too.
The best answer to speed awareness (aside from speedos) would be to simply have a chime that bings when you go over the speed limit for more than a few seconds, just like if you don’t put your seatbelt on. It doesn’t force you to wear one but it makes it very annoying if you don’t.
Meanwhile if you want to go fast, goto Silverstone, or goto Germany and get your Kraftwerk vibe on.
There seems to be a bit of a difference in how these devices are portrayed, favourable press has been calling them ISA or Intelligent Speed Assistance and the negative press Speed Limiters forgetting that there is a manual override. I think most of us just limit our speed due to years of seeing the unexpected appear and drive appropriately for road conditions often below the speed limit.
There is an existing use case where people invite black boxes into their cars to record their driving and that tends to be younger people who want insurance and can’t get it without paying £4-5k. Getting Black box insurance reduces their premiums by thousands and is a very good incentive to drive properly as you are getting paid to do so, if you don’t your premiums will go up.
I think it is likely that over time insurers will give a discount for having these ISAs/Speed Limiters switched on sending some data back encouraging usage. Let’s face it, they will consider a driver that doesn’t want the speed assistance a higher risk.
People’s attitudes change. Let’s face it seatbelt laws were seen originally as a restriction on our own freedom and it took 15 years between making it compulsory to fit them in cars to making it compulsory to wear them.
Agreed with all that but am very concerned with any software based system branded as intelligent. In almost all instances this is just a smart algorithm so best people are aware there is nothing intrinsically intelligent in that black box. If there was, you would have a devil of a time testing it.