We have had a blanket 20mph limit in our area for several years now, supposedly introduced to reduce harmful emissions and make it safer for kids walking to school. Personally I stick to the limit which really winds up some drivers in a rush, and Amazon, supermarket vans, DPD, Tesco, EVri, DHL, FedEx, UPS, local postie...

Funny thing is I have NEVER seen the limit monitored or imposed, NEVER heard of anyone getting a speeding ticket despite seeing it happen on a daily basis, and as for kids walking to school, huh, it's the school run cars that are the worst offenders