M4 postcode district road traffic accidents
The M4 postcode district recorded 1,256 collisions in the STATS19 data between 1999 and 2025, involving 1,758 casualties. Of these collisions, 16 were fatal and 148 were serious. Recorded collisions in 2025 were down 56% on 2024.
Severity Breakdown
- Fatal
- 16
- Serious
- 148
- Casualties
- 1,758
- Fatal
- 16
- Serious
- 148
- Casualties
- 1,758
Collisions by Year
Areas covering M4
Towns in M4
Roads in M4
Planning applications nearby
Data from PlanIndex, an index of UK planning registers.
Data from PlanIndex, an index of UK planning registers.
Accidents in the M4 postcode district
Road collision statistics for the M4 postcode district
Collisions recorded
1,256
Police-reported road traffic collisions captured in the STATS19 data.
People injured or killed
1,758
Casualties recorded across every collision in this area.
Fatal collisions
16
Collisions in which at least one person died.
Serious collisions
148
13.1% of collisions here ended in a death or serious injury.
Severity of collisions
What the data shows in the M4 postcode district
Collisions in the M4 postcode district are most frequently recorded on a Saturday (15.5% of the total), with 33.4% happening in darkness rather than daylight. The most common posted speed limit at the scene is 30 mph.
57.4% of recorded collisions in the M4 postcode district happen on a single carriageway. Around 22.5% were recorded in adverse weather such as rain, snow or fog.
The collisions in the M4 postcode district have produced 1,758 casualties. Pedestrians account for 28.5% of those casualties, a marker of the risk to people on foot here.
Collisions by day of the week
Collisions by day of the week: Sunday 167 collisions, Monday 175 collisions, Tuesday 158 collisions, Wednesday 193 collisions, Thursday 179 collisions, Friday 189 collisions, Saturday 195 collisions.
Light conditions
Light conditions: Daylight 836 collisions, Darkness 420 collisions.
Road type
Road type: Single carriageway 721 collisions, Dual carriageway 208 collisions, One way street 174 collisions, One way street/Slip road 112 collisions, Unknown 36 collisions, Slip road 5 collisions.
Speed limit at the scene
Speed limit at the scene: 20 mph 136 collisions, 30 mph 1,119 collisions, 40 mph 1 collisions.
Weather at the time
Weather at the time: Fine no high winds 974 collisions, Raining no high winds 190 collisions, Unknown 29 collisions, Raining + high winds 25 collisions, Other 24 collisions.
Who was hurt
Who was hurt: Driver or rider 680 casualties, Passenger 577 casualties, Pedestrian 501 casualties.
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Recent Accidents
Showing 20 of 1,256 accidents
Accident 201606A010462
SlightAccident 201506A009877
SlightAccident 201506A009855
SlightAccident 201506A008932
SlightAccident 201506A008275
SlightAccident 201506A007110
SeriousAccident 201506A008257
SlightAccident 201506A008089
SeriousAccident 201506A007562
SlightAccident 201506A006050
SlightAccident 201506A006072
SlightAccident 201506A004796
SlightAccident 201506A004318
SeriousAccident 201506A003851
SlightAccident 201506A004006
SlightAccident 201506A002987
SlightAccident 201506A002864
SeriousAccident 201506A001625
SlightAccident 201506A001379
SeriousAccident 201506A001166
SlightFrequently asked questions about road accidents in the M4 postcode district
How many road accidents have there been in the M4 postcode district?
1,256 collisions have been recorded in the M4 postcode district in the STATS19 road safety data between 1999 and 2025, involving 1,758 casualties.
How many of the collisions in the M4 postcode district were serious or fatal?
16 were fatal and 148 were serious — 13.1% of all recorded collisions in the M4 postcode district resulted in a death or serious injury.
When do most road accidents happen in the M4 postcode district?
Saturday is the most common day for collisions in the M4 postcode district, accounting for 15.5% of them, and 33.4% of all collisions here happen in darkness.
What kind of roads do collisions in the M4 postcode district happen on?
57.4% of collisions in the M4 postcode district are recorded on a single carriageway, most often where the limit is 30 mph.
Are pedestrians often hurt in collisions in the M4 postcode district?
Pedestrians make up 28.5% of the 1,758 casualties recorded in the M4 postcode district.
Is road safety in the M4 postcode district getting better or worse?
Recorded collisions in the M4 postcode district fell 56% in 2025 compared with 2024, though year-on-year figures move with both genuine risk and changes in reporting.
Where does the road accident data for the M4 postcode district come from?
It comes from STATS19, the official record of personal-injury road collisions reported to the police and published by the Department for Transport. The figures for the M4 postcode district cover 1999 to 2025.