
20mph Speed Limits
for Safer and Healthier Welsh Streets
About 20mph in Carmarthenshire
On 17 September 2023, Welsh Government legislation came into force which reduced the speed limit to 20mph in most built-up areas with street lighting.
The Welsh Government has made this change for a number of reasons. Please visit their website to learn more about this change.
This legislation, brought in by Welsh Government, means that all restricted roads that were formerly 30mph, have now become 20mph, apart from certain roads where the County Council have made exceptions for specific lengths of roads and specific traffic orders made.
Restricted roads are usually located in residential and built-up areas where there are many different road users but especially where pedestrians and cyclists are mixing with traffic. They normally have streetlights on them, placed no more than 200 yards apart. As was the case with the default 30mph limit, the new default 20mph limits do not require repeater signs. The Welsh Government campaign is highlighting – See Streetlights – Think 20mph, unless there are speed limit signs telling you any different.
Exceptions before 17 September
Ahead of the legislation coming into force on 17 September 2023, Carmarthenshire County Council implemented a total of 106 exceptions across its 3,500km road network, which is the second largest road network in Wales.
Whilst exceptions can be made by each local authority, the criteria for exempting a restricted road must comply with Welsh Government’s guidance document and would have to be substantiated by a significant body of evidence for raising the default 20mph to 30mph. Please visit the Welsh Government’s website to view the guidance. The guidance also makes clear which roads should default to 20mph, based on a set criteria.
Local authorities do not choose or decide which roads are designated with a 20mph speed limit, however, we have had to assess and justify those roads that were deemed suitable to be subject to 30mph under the exception criteria and based on strong supporting evidence.
Traffic regulation orders are required to create the 30mph exceptions, even though the speed limits would have been 30mph before 17 September 2023.

About 20mph in Carmarthenshire
On 17 September 2023, Welsh Government legislation came into force which reduced the speed limit to 20mph in most built-up areas with street lighting.
The Welsh Government has made this change for a number of reasons. Please visit their website to learn more about this change.
This legislation, brought in by Welsh Government, means that all restricted roads that were formerly 30mph, have now become 20mph, apart from certain roads where the County Council have made exceptions for specific lengths of roads and specific traffic orders made.
Restricted roads are usually located in residential and built-up areas where there are many different road users but especially where pedestrians and cyclists are mixing with traffic. They normally have streetlights on them, placed no more than 200 yards apart. As was the case with the default 30mph limit, the new default 20mph limits do not require repeater signs. The Welsh Government campaign is highlighting – See Streetlights – Think 20mph, unless there are speed limit signs telling you any different.
Exceptions before 17 September
Ahead of the legislation coming into force on 17 September 2023, Carmarthenshire County Council implemented a total of 106 exceptions across its 3,500km road network, which is the second largest road network in Wales.
Whilst exceptions can be made by each local authority, the criteria for exempting a restricted road must comply with Welsh Government’s guidance document and would have to be substantiated by a significant body of evidence for raising the default 20mph to 30mph. Please visit the Welsh Government’s website to view the guidance. The guidance also makes clear which roads should default to 20mph, based on a set criteria.
Local authorities do not choose or decide which roads are designated with a 20mph speed limit, however, we have had to assess and justify those roads that were deemed suitable to be subject to 30mph under the exception criteria and based on strong supporting evidence.
Traffic regulation orders are required to create the 30mph exceptions, even though the speed limits would have been 30mph before 17 September 2023.
Will the Council be introducing further exceptions?
There is consideration being given to agree on a national approach, across Wales, to assess future requests for exceptions, by applying a common set of principles to ensure a consistent application and uniformity for motorists.
It is also suggested that a ‘settling-in’ period should apply to allow more meaningful discussions in advancing this matter, whilst drivers and communities get used to the new speed limits. The length of the suggested “settling period” is currently being discussed and considered nationally and the Council awaits Welsh Government’s guidance on this matter.
Once agreement has been reached, we will be in a position to consider a strategic approach to reviewing our network, possibly looking at our key roads of strategic importance as an initial priority. This approach will of course give us time to assess how the new speed limits have changed driver behaviour, affected traffic speed and contributed to road safety.
Whilst there will be a process whereby communities or individuals can request that we review a particular speed limit, it should be noted that we will have to apply a structured and prioritised approach to any such requests, as we will not be able to react to all requests simultaneously and where any changes are to be made, a Traffic Regulation Order will need to be created, which is a lengthy legal process subject to comment and potential objection.
Legal advice has been sought on the process and criteria for making exceptions to the 20mph default speed limit. Exceptions must, therefore, be based on fact and supporting evidence as opposed to an arbitrary assessment based on general opinion, or the number of requests received.
Each exception must be considered on its own merit and be supported by site specific evidence to support raising the speed limit from the default 20mph up to 30mph.
Each exemption must also follow a set legal process in making a traffic regulation order to raise the speed limit to 30mph.
How will future exemptions be funded?
Any future exceptions will be dependent on funding from Welsh Government.
What does the early data tell us?
Preliminary data at monitoring sites around Carmarthenshire are currently showing a marked reduction in traffic speeds ranging from 5mph up to 9mph since the introduction of the 20mph speed limits.
Reporting Speeding Concerns
The role of enforcing the existing speed limit rests with the Police and GoSafe rather than the County Council as we have no enforcement powers in this respect. You can submit a community speeding concern directly with GoSafe, and they will investigate.
You can learn more about the Police and GoSafe’s approach to enforcing the 20mph limit here:

Will the Council be introducing further exceptions?
There is consideration being given to agree on a national approach, across Wales, to assess future requests for exceptions, by applying a common set of principles to ensure a consistent application and uniformity for motorists.
It is also suggested that a ‘settling-in’ period should apply to allow more meaningful discussions in advancing this matter, whilst drivers and communities get used to the new speed limits. The length of the suggested “settling period” is currently being discussed and considered nationally and the Council awaits Welsh Government’s guidance on this matter.
Once agreement has been reached, we will be in a position to consider a strategic approach to reviewing our network, possibly looking at our key roads of strategic importance as an initial priority. This approach will of course give us time to assess how the new speed limits have changed driver behaviour, affected traffic speed and contributed to road safety.
Whilst there will be a process whereby communities or individuals can request that we review a particular speed limit, it should be noted that we will have to apply a structured and prioritised approach to any such requests, as we will not be able to react to all requests simultaneously and where any changes are to be made, a Traffic Regulation Order will need to be created, which is a lengthy legal process subject to comment and potential objection.
Legal advice has been sought on the process and criteria for making exceptions to the 20mph default speed limit. Exceptions must, therefore, be based on fact and supporting evidence as opposed to an arbitrary assessment based on general opinion, or the number of requests received.
Each exception must be considered on its own merit and be supported by site specific evidence to support raising the speed limit from the default 20mph up to 30mph.
Each exemption must also follow a set legal process in making a traffic regulation order to raise the speed limit to 30mph.
How will future exemptions be funded?
Any future exceptions will be dependent on funding from Welsh Government.
What does the early data tell us?
Preliminary data at monitoring sites around Carmarthenshire are currently showing a marked reduction in traffic speeds ranging from 5mph up to 9mph since the introduction of the 20mph speed limits.
Reporting Speeding Concerns
The role of enforcing the existing speed limit rests with the Police and GoSafe rather than the County Council as we have no enforcement powers in this respect. You can submit a community speeding concern directly with GoSafe, and they will investigate.
You can learn more about the Police and GoSafe’s approach to enforcing the 20mph limit here: