The introduction of a default 20mph speed limit for roads in Wales has been planned for April 2023.
Eight pilot areas have been chosen to trial the change this coming summer.
Lee Waters, Deputy Minister for Economy and Transport, said the move will reduce accidents and save lives.
The pilot areas will have a phased start from this summer until the end of the year.
The areas chosen are intended to be representative of different villages, towns and cities across Wales.
The Welsh Government said it is introducing the new speed limit to improve safety and help make Welsh streets a more welcoming place for cyclists and pedestrians.
Initial findings from a national public attitude survey have found support for the plans.
According to the Welsh Government, 92% of those surveyed who wanted a change to the speed limit on their street suggested a speed limit of 20mph or lower, while 77% said they wanted to see this speed limit applied throughout the area in which they live.
Lee Waters, Deputy Minister for Economy and Transport, said: “Making 20mph the default speed limit in residential areas is a bold step that will save lives.
“We have made progress on reducing deaths and serious injuries on our roads over the 21 years of devolution, but despite our considerable efforts the highest proportion of all casualties – 50% – occurred on 30mph roads during 2018.
“This cannot be tolerated, so a reduction to 20mph on our residential and other busy pedestrian urban roads has to be the way forward.”
The eight pilot locations are:
- Abergavenny, Monmouthshire
- Central North, Cardiff
- Severnside, Monmouthshire
- Buckley, Flintshire
- Cilfriw Village, Neath and Port Talbot
- St Dogmaels, Pembrokeshire
- St Brides Major, Vale of Glamorgan
- Llanelli North, Carmarthenshire