Researchers at the Transport Research Institute at Edinburgh Napier University have estimated that making 20mph the default speed limit in Wales will generate a cost savings of around £100m in its first year alone, through a reduction in the number and severity of road collisions.

Critics of the default limit, which will apply from 17 September, have argued that it would be better to spend the money on other things. A week before the Napier research was published, the leader and deputy leader of Wrexham Council said the 20mph limit was the wrong priority during the cost of living crisis (see story below).