I read this as the speed limiter would work on GPS i.e. the limiter would work according to mapped speed limits.
That seems to be the case, but may also use a camera. According to the BBC report (link posted previously seems to have disappeared?):
“Under the ISA system, cars receive information via GPS and a digital map, telling the vehicle what the speed limit is.
This can be combined with a video camera capable of recognising road signs.”
At least there is a recognition that the technology has some way to go yet:
“However, there is concern over whether current technology is sufficiently advanced for the system to work effectively.
In particular, many cars already have a forward-facing camera, but there is a question mark over whether the sign-recognition technology is up to scratch.”
It’ll be interesting to see which positioning system will be used. It may not be coincidental that EU has mandated this at about the same time as EU’s Galileo is coming on line, with its promise of greater position accuracy (allegedly even the open public system is accurate enough to detect which lane a car is in, not just which road it’s on) and independence of the US military system that we all use at present.