The Welsh Labour Government has been accused of a “waste of time and resources” after new figures revealed speeds have reduced by 4mph since the imposition of the 20mph limit.

Data collected by Transport for Wales (TfW) shows average speeds on main roads in Wales have dropped from 28.9mph to 24.8mph following the rollout.

Welsh Conservative Shadow Minister for Transport Natasha Asghar said: “These findings prove what a monumental waste of time and resources from the Labour Government the 20mph limit has been.

“To sacrifice billions of pounds from the Welsh economy all for the sake of 4mph may satisfy Labour, but it is not a trade the Welsh Conservatives would be willing to make.

“On day one of a Welsh Conservative Government, this barmy policy would be scrapped, and common sense would prevail.”

Mark Drakeford’s administration sparked a backlash with the change which was implemented last September.

Lee Waters, Wales’s deputy minister for climate change, said: “The latest data published today is clear evidence that average speeds are coming down on roads across Wales.

“We also know from data published by Go Safe earlier this month that 97% of drivers are complying with the new slower speed limit – behaviours and attitudes towards 20mph are beginning to change.

“We’ve still got a way to go, but it’s encouraging to see that things are moving in the right direction. Every 1mph reduction in speed makes a real difference – so this is a real turning point.”

Mr Waters added that evidence was clear that lower speeds would help save lives, lead to fewer injuries and reduce the impact on the NHS.

It comes as a petition against the new speed limit on the Welsh Parliament’s website has now been signed by almost 469,000 people.