My speed limit reminders work of GPS I think, fairly accurate but some strange anomalies here and there. I do have a speed limiter, but it's up to me whether to turn it on, and at what speed to set it, don't really use it to be honest. The Renault Megane I drove last year used cameras like a Tesla to read the signs.

Interesting. If it can be done, I'm sure MOST everyone turns off that feature.