Asked by: Baroness D'Souza (Crossbench - Life peer)
Question to the Department for Transport:
To ask His Majesty's Government, further to the Written Answer by Lord Hendy of Richmond Hill on 7 April 2025 (HL6099) and the remarks by Lord Hendy of Richmond Hill on 21 January (HL Deb col 279), what is the reason for the 20 miles per hour speed limit in London and other cities.
Answered by Lord Hendy of Richmond Hill - Minister of State (Department for Transport)
The power to impose 20mph speed limits rests with the local traffic authority. As well as influencing safety, such limits can positively affect quality of life, the environment and the local economy. The standard speed limit in urban areas is 30mph, which represents a balance between mobility, safety and other factors, but in specific areas traffic authorities can consider implementing of 20mph schemes, for example outside schools.
Authorities are asked to have regard to the Department for Transport’s guidance on Setting Local Speed Limits which as outlined in the Road Safety Strategy will be reviewed to further support local authorities in making well‑informed decisions about managing speed on their roads.
Asked by: Baroness D'Souza (Crossbench - Life peer)
Question to the Department for Transport:
To ask His Majesty's Government whether they have observed a reduction in death and injury caused by road traffic accidents in areas, such as central London, which have introduced a 20 miles per hour speed limit.
Answered by Lord Hendy of Richmond Hill - Minister of State (Department for Transport)
The Department for Transport published a comprehensive three-year evaluation of the effect of 20mph limits, which are 20mph schemes relying only on signage, on 22 November 2018.
The evaluation looked at twelve case studies including two in city centres (Brighton and Winchester). No case studies were in London.
It found insufficient evidence to conclude that that there had been a significant change in collisions and casualties following the introduction of 20mph limits in residential areas.
The only case study area showing a significant change in collisions and casualties, relative to its 30mph comparator area, was Brighton City Centre. This scheme covered both major and minor roads, with a 19% reduction in overall casualties, a 29% reduction in pedestrian casualties and a 51% reduction in casualties aged 75 or over. No significant change in casualties of cyclists or under 16s was found.
The evaluation stated that the changes appeared to be a reflection of the city characteristics, and the blanket implementation of 20mph limits across all roads within the scheme area, including higher flow A and B roads which were typically excluded from the residential case study schemes. There was a significant reduction in collisions across all road types, but the change was most pronounced on major strategic roads. The evaluation stressed that this represented just one case study, and the extent to which the findings were transferable to other locations was unclear.