Where are 20mph speed limits in place across England and Wales?

Welsh ministers have claimed that the controversial new 20mph speed limit has proved successful after figures suggested average speeds had dropped by 4mph. 

Transport for Wales measured speeds from 3.4 million vehicles across nine locations in Wales over two weeks at the end of November and the start of December.

It found that average speeds on the 20mph roads it studied fell from 28.9mph before the rollout to 24.8mph.

Although this is above the new — which prompted backlash when implemented at the end of last year — the Welsh government said it was "very encouraged