The A40: where people are seriously hurt
Over 2021–2025, 601 people were killed or seriously injured in 518 collisions on the A40, making it the 6th worst numbered road in Britain by that measure.
518
serious or fatal collisions
601
people killed or seriously injured
39
collisions that took a life
#6
of 150 numbered roads
What the record shows
The A40 carries 2,091 recorded injury collisions over the period, 518 of them serious or fatal. Serious injury concentrates in Westminster, Carmarthenshire, Buckinghamshire, with 3 further areas also recording collisions. Its fatal share, 8%, sits close to the 7% average for the numbered network. Most collisions were recorded on 30 mph sections. The worst year of the period was 2025 with 112 serious collisions, and the count is up 20% between 2021 and 2025.
Every serious and fatal collision on the A40
Blue markers are serious collisions, red crosses fatal. Click any marker for the year. Zoom in to see the specific junctions and stretches where they cluster.
Where along the route
- Westminster77 KSI
- Carmarthenshire51 KSI
- Buckinghamshire49 KSI
- Ealing47 KSI
- Cotswold32 KSI
- Pembrokeshire30 KSI
Local authority areas with the most serious collisions on this road.
The trend
Serious and fatal collisions on the A40
2025: 112 (up 4.7% on the year before) · peak 112 in 2025 · +20.4% across the period
Axis clipped to the data range to show year-on-year movement.
About the A40
How many accidents happen on the A40?
Police recorded 2,091 injury collisions on the A40 over 2021–2025, of which 518 were fatal or serious. Those serious collisions left 601 people killed or seriously injured, including 39 fatal collisions.
Is the A40 a dangerous road?
By volume of serious injury it ranks 6 of the 150 numbered roads we analyse, and 6 among a roads. That is a count rather than a rate: longer and busier roads accumulate more collisions, so a high ranking reflects exposure as well as risk.
Where on the A40 do collisions happen?
They concentrate in Westminster, Carmarthenshire, Buckinghamshire. The map on this page plots every serious and fatal collision recorded on the route, so you can see the specific stretches rather than the total.
Counts include every collision the police recorded on this road number across all authority areas. They are not adjusted for traffic volume or road length, so treat them as a measure of where injury concentrates rather than a per-mile risk rating. Method. Free to reuse with attribution to this page.
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