The national 20mph limit has had a 5-year history of wide support within the Senedd.

Since 1934, Welsh roads with lighting have had a national speed limit set by the Westminster government of 30mph. However, local Highway Authorities (usually city or county councils) have had the power and responsibility to set individual roads at different speeds (either lower or higher) by means of a Traffic Regulation Order. National governments provide guidance on the setting of such local variations on the 30mph national limit. The Welsh guidance dates from 2009 in the form of the "Setting Local Speed Limits in Wales" document.  This was modelled on the previous DfT guidance from 2006. In both of these 20mph speed limits were only advised for "individual roads or for a small network of roads".

Since 2006 many local authorities in England had been going beyond this guidance and setting 20mph limits for most roads in their jurisdiction with positive results. In 2013 the guidance for England was changed to include the implementation of 20mph limits over a large number of roads. This accelerated the adoption of 20mph as a norm in many English local authorities, and there was increasing recognition that setting 20mph as a norm in urban and village locations was beneficial. This was further enhanced in 2016 when changes to UK-wide signage regulations enabled 20mph repeater signs and roundels to be used as "traffic calming devices" within expanded 20mph zones. 

Some local authorities in England were calling on UK government to change the national limit from what they considered an unfit-for-purpose 30mph to 20mph and enable the local authority to set higher limits as exceptions on particular roads. 

At this time in Wales, there had been no change in the guidance on setting local speed limits from the Welsh Government and in Wales 20mph roads were expensive to implement (due to requiring physical calming) and hence relatively uncommon. However the Wales Act 2017 was enacted in 2018 by the current Conservative government and devolved the setting of national speed limits for restricted (lit) roads to the Welsh ministers with certain provisos on consulting with the UK Secretary of State and approved by a resolution in the National Assembly for Wales. This altered the Road Traffic Act 1984 to accommodate this.

It was in May 2018 that 20's Plenty were invited to discuss with Welsh political leaders and institutions specifically on how this Act enabled a far "smarter" and more cost-effective way to set 20mph limits by making them the national limit for restricted roads as a default and allowing local authorities to set higher exceptions. This included meetings with Andrew RT Davies AM (Welsh Conservatives), Vaughan Gething AM (Welsh Labour) and Leanne Wood AM (Plaid Cymru).  

Subsequent to this and discussions within and across parties in September 2018 a debate was held in Senedd tabled by Welsh Conservative members with cross party support from Welsh Labour, Plaid Cymru, Lib-Dems and Independents to "introduce legislation so that a 20mph speed limit becomes the standard speed limit in Welsh residential areas".

The following month Conservative AM David Melding and Labour AM John Griffiths MS spoke at the 20's Plenty conference held in Cardiff on Oct 2nd 2018. Both were advocating a national 20mph default within the conference. This specifically discussed setting 20mph as a national default limit and had wide political and institutional support.

This led to the Deputy Minister for Economy and Transport for the Welsh Government setting up a "Welsh 20mph Task Force Group" in May 2019 to "identify the outcomes which would be expected from changing the default speed limit for restricted roads in Wales to 20mph, and the practical actions needed to implement this change in law". This was chaired by Phil Jones and included a wide range of participants including police, local authorities, emergency service, government officers and NGOs, as well as motoring, public transport and freight organisations. The "Final Report" was published in July 2020 and included the case for change and 20 recommendations on how to implement such a change. On 15th July 2020 the Senedd duly debated the findings of the report in a plenary session and passed motion NDM7355 supporting the Welsh Government's intention to set a national 20mph limit for restricted roads subject to subsequent approval by resolution of Senedd.

This motion supported by 85% of the Members of Senedd showed a clear democratic and cross-party support for the proposal. It was particularly pleasing to see the wide support from Welsh Conservative Members of Senedd.

Listen to Janet Finch-Saunders AM speaking in favour of the recommendations in the report in the debate in Senedd.

Subsequent to this the intention to set such a 20mph national limit was specifically included in the 2021 election manifestos of two of the major Welsh political parties. These parties received 60.2% of the constituency votes and  56.9% of regional votes, with a combined majority of 43 out of 60 Senedd seats.

Based on the cross-party support in the 2020 debate and the inclusion of the national 20mph initiative as a key manifesto policy, the Welsh Government went on to propose legislation in the form of a Statutory Instrument to set a national 20mph limit for restricted roads in Wales and "The Restricted Roads (20mph Speed Limit) Order 2022 was debated (NDM8054) and passed in a plenary session in Senedd on 12th July 2022. It was passed by a majority 39 votes (72%) for and 15 (28%) against.

This legislation sets an effective date of 17th September 2023 for the national 30mph limit for restricted roads to change to 20mph. The Welsh Government has issued guidance to assist local authorities in setting exceptions. Note that the authority and responsibility to set local exceptions to a national speed lies exclusively with the local Highway Authority. The national guidance is simply guidance and not a mandatory rule. How local authorities interpret or adhere to that guidance is their responsibility rather than that of the national government.

Hence, the setting of a national 20mph limit for restricted roads has had consistent support over 5 years, since the devolution of such powers to the Senedd by the UK government.  It has had cross-party support for all the development work in the initiative and also been clearly publicised in the election manifestos of the two major political parties who comprise a majority in Senedd. It has had extensive consideration of the expected outcomes and method for implementation. It has received all the necessary requirements for legislation including two affirmative votes in the Senedd and the necessary consultation with the UK Secretary of State.

It has been through all appropriate and necessary democratic processes for setting such national legislation.