20mph limits in London linked to sharp fall in road injuries and deaths, new report finds
A new study published by Transport for London (TfL) has shown that the introduction of 20mph speed limits and zones on local authority-managed roads in London between 1989 and 2013 led to significant reductions in collisions, injuries, and deaths, particularly among children and vulnerable road users.
The report, based on data from 157 individual 20mph schemes and a comparative analysis using a control group of all borough roads, provides strong evidence of the benefits of reducing speed limits in urban areas. The findings support the wider roll-out of lower speed limits as a core component of Vision Zero — London’s plan to eliminate road deaths and serious injuries by 2041.
Across all the schemes studied, the results were consistently positive:
- Total collisions fell by 35% (compared to 12% in the control group)
- All casualties fell by 36%
- Fatal or serious injuries fell by 34%
- Child casualties dropped by 46%, and children killed by 75%
- Among people walking, cycling, or riding motorcycles, killed or seriously injured (KSI) figures were reduced by 28%
The report not only confirms the road safety benefits of lower speed limits, but also echoes findings from other UK cities such as Edinburgh, Bristol and Portsmouth, as well as initial data from Wales following its implementation of a default 20mph limit. These schemes contribute to broader public health, environmental and economic benefits by encouraging active travel, improving air quality, reducing noise, and lowering emergency and healthcare costs associated with road crashes.
ETSC welcomes the publication of this study and sees it as a vital contribution to the growing body of evidence supporting reduced speed limits in urban areas. With road deaths stagnating across Europe, proven interventions such as lower speed limits should be central to national and local strategies to improve road safety.