I think a speed limiter with an over ride facility is not a speed limiter
A limiter with no override is fine if it only enforces a single (upper) limit, but this new technology has to adjust to
different limits.
Mrs L's car has a camera based speed limit recognition system (not enforced, information only). It occasionally misses a sign, so potentially it could state a 20 limit after you've driven from a town onto a motorway. Imagine that being enforced with no override!
Seems to be the limiter is a great idea (albeit with override). It also helps build the case for zero tolerance enforcement.
It also seems to me that a compulsory black box is going to make the most difference.