May be as well as cruise control-a limiter could be fitted into the electronics, get into a 30 zone, hit the 30 button and car wont go any faster till you cancel it. Think merc trucks do that-no chance of just accidently speeding.
Would be good on those open single lane carrigeways where speed just creeps up. and would also mean you can concentrate on driving not the speedo. foot down wont matter but u can slow down as and when u want.
There is no excuse for speeding-have accepted all my speeding points.