I always assumed it was about slowing cars from 35 to 25mph as hardly anybody sticks to the speed limit. Llywodraeth Cymru (Welsh Government) claims that a pub

I always assumed it was about slowing cars from 35 to 25mph as hardly anybody sticks to the speed limit. Llywodraeth Cymru (Welsh Government) claims that a public health study suggests its new 20mph limits will see, annually, a 40 per cent reduction in collisions, between six and ten lives saved, and anything from 1,200 to 2,000 people avoiding injury as a result. Scale that up across the country and you are looking at way more than "4 or 5 lives".