New Study Reveals Driver Speeds on Wales’ 20mph Roads
Transport for Wales has recently released data on the driving speeds of motorists on Wales’ 20mph roads, shedding light on the average speeds nearly 18 months after the speed limit change was put into effect. The transition to a default 20mph limit on previously 30mph roads was completed in September 2023.
Conducting monitoring at 43 locations in 10 different regions across Wales since the summer of 2023, Transport for Wales collected data from approximately seven million vehicle journeys per monitoring period. The study focused on various statistics, including the proportion of drivers adhering to or below 24mph on roads that shifted from 30mph to 20mph, as well as the weighted average speed of all drivers.
Before the implementation of the new speed limit in the summer of 2023, 20.8% of drivers were found driving at or under 24mph. During the same period, about 37% of drivers were exceeding 30mph, with 10.4% reaching speeds of 35mph or higher. The weighted average speed of all drivers for that period was recorded at 28.7mph.
The monitoring process was repeated in subsequent periods, including the winter of 2023/24, summer of 2024, and winter of 2024/25. The latest data from January 2025 revealed that 54% of drivers at the monitored sites were driving at or below 24mph, marking a 33% increase compared to the figures from summer 2023.
The percentage of drivers exceeding 30mph on these roads decreased to 15.2%, with only 3.9% surpassing 35mph. The average speed of all drivers was documented at 24.9mph, showcasing a notable drop of approximately 4mph compared to the summer of 2023.
Studies from The Royal Society for the Prevention of Accidents highlight that the risk of a pedestrian being fatally struck at 20mph is estimated to be 1.5%, significantly lower than the 8% risk at 30mph. Despite the ongoing debate surrounding the 20mph limit, it has led to a reduction in road collisions, fatalities, and injuries across Wales.
Following the implementation of the default 20mph speed limit, police data indicated that around 100 fewer individuals were killed or severely injured on roads with 20mph and 30mph speed limits in the year post-implementation compared to the previous year. However, there has been an uptick in the number of drivers receiving fines, with violations rising from 62,742 in 2023 to 97,088 in 2024 in north Wales alone.
Concerns have been raised regarding the economic impact of the new speed limit, as average driving times have extended. Local authorities are considering the introduction of more ‘exception’ roads where the speed limit will revert to 30mph. Although the implementation of the 20mph limit came at a cost of over £32m, additional funding is anticipated for the modifications required for exception roads.