30mph roads in Conwy and Denbighshire will be reduced to 20mph, apart from those exempt following a special application.

But exemptions will be granted only if ‘significant’ numbers of pedestrians and cyclists aren’t present.

Both councils will see the speed limits reduced from 30mph to 20mph as part of Welsh Government legislation aimed at reducing serious injuries and encouraging more people to cycle or walk.

The new legislation says councils can apply for roads to be exempt if there aren’t ‘significant’ numbers of pedestrians and cyclists travelling along or across the road.

But speed limits on roads in built-up areas are likely to be reduced.

According to the legislation on the Welsh Government website, decisions on exceptions to the new speed limit shouldn’t be influenced by existing speed limits, and sections of roads being on bus routes is also not considered a reason for an exception.

The change in speed limit will come into effect on September 17 this year, but councils across Wales are announcing exempt roads at different times – with authorities like Anglesey carrying out a public consultation on the plans.

The speed limit changes brought in by the Labour Government have attracted criticism from the Conservatives, who claim it could damage businesses.

Councils had been urged to engage with local communities about the changes.

A spokeswoman for Conwy County Council commented: “The legislation coming into force in September 2023 will change the default speed limit in all urban and residential areas from 30 mph to 20 mph.

“The speed limit on restricted roads will usually be changed to 20 mph. Restricted roads include streetlights placed no more than 200 yards apart. They are usually located in residential and built-up areas with high pedestrian activity.

“There are nationally agreed criteria to identify roads which are exceptions and will remain at 30 mph.”

She added: “The final list for Conwy is yet to be confirmed.”

A spokesman for Denbighshire County Council said: “The council is responding to the legislative change made by the Welsh Government in respect to the introduction of the 20 mph limit in September across towns and villages in Wales.

“We are discussing the introduction of the 20mph limit with our elected members and will be engaging with our city, town and community councils., This will all help inform officers of potential exemptions that need to be identified. “