It was stated that the 20 MPH limit also requires traffic calming measures, this was the reason given for the use of the non enforceable 20 MPH signs with red 20 inside a black ring used at schools in Flintshire, the problem was as not enforceable they had no cancel signs, so drivers in Flintshire got use to slowing down past school then speeding up again without any end of speed limit sign.
But signs on side roads often look as if they are for major routes, and often the signs have faded in the sun, so it is hard to work out which are valid and which are not, the temporary signs which change from 30 to 20 at school opening and closing times are good, but the real danger is parked cars near school entrances, and cars doing U turns. I know one school would have gates open until coming out time and then closed until all pupils had stopped milling around, i.e. were in the cars, then gates opened, so no cars should have been on the road, and no pupils walking around while cars were moving, seemed so simple, but only seen at one school.
However that is not what the tread was about, although it does show the problems understanding what should be done, and what needs to be done.
As a home owner I can weigh up pros and cons and decide if I want AFDD, SPD, RCD, or any other protection, and decide if I want to risk a freezer failing, or other things which the tripping of a RCD can result in, so do I spend out on RCBO's or take the chance a RCD covering many circuits will not trip.
Where this does not work is with rented accommodation, as cost to fit all RCBO's is the landlords but the cost of loss of food when a freezer fails is the tenants, forcing landlords to fit RCD protection is not always in the tenants interest.