Drivers who go above 50mph on some of Wales' most polluted roads could be fined under new rules on 'environmental speed limits'.

The Welsh Government has already brought in 50mph limits on five stretches of road across the nation, and said the schemes had been a success, so far cutting levels of nitrogen dioxide by up to 47 per cent.

By improving air quality, the scheme is having environmental and health benefits, the government added.

Senedd member Lee Waters, the deputy minister for climate change, said "slower speed limits are not a popular choice, but we need to do things differently and be bold if we are to stand a chance of tackling climate change".

He added: “It’s clear that the speed restrictions we’ve introduced on our most polluted roads are working - the results speak for themselves – but compliance with these limits is essential if we are to achieve the reductions we need to make in the shortest possible time." 

This means that from October 4, anyone speeding on those roads will receive a warning letter or a fine.

The roads affected by the new enforcement measures are:

• A494 Wales/England border to St David’s Interchange, Deeside;

• A483 Junction 5 to Junction 6, Wrexham;

• A470 Upper Boat Interchange to Bridge Street Interchange, Pontypridd;

• M4 Junction 41 to Junction 42, Port Talbot;

• M4 Junction 25 to Junction 26, Newport – a change from variable speed limit enforced by spot speed cameras to a permanent 50mph, to be enforced by average speed enforcement at a future date.

South Wales Police's assistant chief constable, Mark Travis, is in charge of roads policing in Wales. He said the nation's four police forces supported the new enforcement and would approach the new rules "in a consistent, proportionate and transparent manner".

It is also hoped the new enforcement will improve road safety by educating speeding drivers, as well as clamping down on the worst offenders.

Teresa Ciano, from Wales-wide partnership GoSafe, said the plans for a "first of its kind" advisory letter programme means the authorities "will be able to inform people of the importance of complying with the speed limit at these locations, while still prosecuting the most dangerous drivers.” 

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