Oh yes. Quite agree.
But if you look at the "Kill your speed not a child" including the "It's 30 for a reason" adverts in the last few years I can think of several acquaintances who would take no notice of the ads.
So, should there be more advertisements or whole programmes?
'Fraid I don't know the answer Alistair

Thinking about it, I haven't read the latest Highway Code, either