The M3: where people are seriously hurt
Over 2021–2025, 136 people were killed or seriously injured in 119 collisions on the M3, making it the 95th worst numbered road in Britain by that measure.
119
serious or fatal collisions
136
people killed or seriously injured
9
collisions that took a life
#95
of 150 numbered roads
What the record shows
The M3 carries 571 recorded injury collisions over the period, 119 of them serious or fatal. Serious injury concentrates in Winchester, Surrey Heath, Runnymede, 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 70 mph sections. The worst year of the period was 2024 with 31 serious collisions, and the count is down 57% between 2021 and 2025.
Every serious and fatal collision on the M3
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
- Winchester37 KSI
- Surrey Heath23 KSI
- Runnymede20 KSI
- Hart15 KSI
- Basingstoke and Deane10 KSI
- Eastleigh8 KSI
Local authority areas with the most serious collisions on this road.
The trend
Serious and fatal collisions on the M3
2025: 13 (down 58.1% on the year before) · peak 31 in 2024 · -56.7% across the period
Axis clipped to the data range to show year-on-year movement.
About the M3
How many accidents happen on the M3?
Police recorded 571 injury collisions on the M3 over 2021–2025, of which 119 were fatal or serious. Those serious collisions left 136 people killed or seriously injured, including 9 fatal collisions.
Is the M3 a dangerous road?
By volume of serious injury it ranks 95 of the 150 numbered roads we analyse, and 8 among motorways. 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 M3 do collisions happen?
They concentrate in Winchester, Surrey Heath, Runnymede. 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.
Need this data for your own work?
Site and junction reports from £95, next working day. Free for community groups, campaigners and journalists.