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CrashStats

M4 accidents: crash map and statistics

Police recorded 29,200 collisions on the M4 from 1979 to 2025, with 46,338 casualties. Of those crashes, 724 were fatal and 4,059 serious, and 859 people were killed.

In 2025 there were 252 collisions on the M4, up 17% from 216 in 2024, with 385 casualties.

Live M4 closures, incidents and roadworks are checked every 5 minutes.

Collisions since 1979
29,200
17th highest of 4,923 roads
Casualties
46,338
1.59 per collision
Fatal collisions
724
859 people killed
Serious collisions
4,059
5,558 seriously injured
Collisions in 2025
252
Up 17% on 2024
Casualties in 2025
385
Up 26% on 2024

Crash severity on the M4

On the M4, 2.5% of collisions were fatal and 14% serious, against 1.6% and 18% across Great Britain.

Collisions by severity, 1979 to 2025

  • Fatal7242.5%
  • Serious4,05914%
  • Slight24,41784%

Where the M4 ranks among 4,923 roads

Most collisions
17th
Most casualties
14th
Most fatal collisions
13th
Most serious collisions
26th

M4 accidents by year

Collisions on the M4 peaked at 888 in 1990 and were down to 252 in 2025.

Collisions and casualties on the M4, 1979 to 2025

  • Collisions
  • Collisions in 2025: 252
  • Casualties

Source: Department for Transport, STATS19 road safety data

View as a table
YearCollisionsCasualties
2025252385
2024216306
2023220359
2022226339
2021238357
2020178258
2019362534
2018355568
2017400645
2016479765
2015525878
2014574944
2013534876
2012493825
2011530854
2010583903
2009538828
20086621,040
20077801,329
20068441,356
20057721,154
20048671,316
20038761,409
20028271,322
20018551,408
20008641,364
19998521,343
19988601,298
19978351,304
19967821,196
19958121,259
19947611,163
19937591,165
19927391,147
19917301,147
19908881,452
19898351,292
19887631,161
19876911,176
19867491,264
1985639957
19846401,081
1983606970
1982553876
1981564973
1980552861
1979540931

When crashes happen on the M4

Friday has the most collisions on the M4 (5,275), and 3pm to 6pm is the busiest time of day (6,544).

Collisions by day of the week

  • Monday4,145 (14%)
  • Tuesday3,926 (13%)
  • Wednesday3,959 (14%)
  • Thursday4,096 (14%)
  • Friday5,275 (18%)
  • Saturday3,795 (13%)
  • Sunday4,004 (14%)

Collisions by time of day

  • Midnight to 3am1,453 (5%)
  • 3am to 6am1,421 (4.9%)
  • 6am to 9am4,600 (16%)
  • 9am to noon4,270 (15%)
  • Noon to 3pm4,552 (16%)
  • 3pm to 6pm6,544 (22%)
  • 6pm to 9pm4,381 (15%)
  • 9pm to midnight1,979 (6.8%)

Collisions by month

  • January2,297 (7.9%)
  • February2,089 (7.2%)
  • March2,199 (7.5%)
  • April2,229 (7.6%)
  • May2,340 (8%)
  • June2,406 (8.2%)
  • July2,660 (9.1%)
  • August2,753 (9.4%)
  • September2,512 (8.6%)
  • October2,614 (9%)
  • November2,677 (9.2%)
  • December2,424 (8.3%)

Light conditions at the time

  • Daylight20,342 (70%)
  • Dark, street lights lit4,341 (15%)
  • Dark, no street lighting4,068 (14%)
  • Dark, lighting unknown265 (0.9%)
  • Dark, street lights unlit173 (0.6%)
  • Not recorded11 (under 0.1%)

Source: Department for Transport, STATS19 road safety data

Road and weather conditions in M4 crashes

On the M4, 87% of collisions happened where the speed limit was 70 mph and 68% on a dry road surface.

Speed limit at the scene

  • 10 mph1 (under 0.1%)
  • 15 mph1 (under 0.1%)
  • 20 mph5 (under 0.1%)
  • 30 mph530 (1.8%)
  • 40 mph662 (2.3%)
  • 50 mph2,090 (7.2%)
  • 60 mph496 (1.7%)
  • 70 mph25,415 (87%)

Weather at the time

  • Fine, no high winds22,018 (75%)
  • Raining, no high winds4,185 (14%)
  • Raining with high winds762 (2.6%)
  • Fine with high winds606 (2.1%)
  • Other1,287 (4.4%)
  • Not recorded342 (1.2%)

Road surface

  • Dry19,837 (68%)
  • Wet or damp8,729 (30%)
  • Frost or ice358 (1.2%)
  • Snow140 (0.5%)
  • Other84 (0.3%)
  • Not recorded52 (0.2%)

Type of road

  • Dual carriageway26,515 (91%)
  • One way street or slip road1,304 (4.5%)
  • Roundabout1,143 (3.9%)
  • Single carriageway190 (0.7%)
  • Not recorded48 (0.2%)

Source: Department for Transport, STATS19 road safety data

People hurt and vehicles involved in M4 crashes

Car occupants make up 82% of the people killed or injured on the M4, followed by van occupants (5%).

Casualties by road user

  • Car occupant37,947 (82%)
  • Van occupant2,302 (5%)
  • Motorcyclist2,021 (4.4%)
  • Goods vehicle occupant (over 3.5 tonnes)1,679 (3.6%)
  • Bus or coach occupant773 (1.7%)
  • Taxi or private hire car occupant509 (1.1%)
  • Minibus occupant493 (1.1%)
  • Other614 (1.3%)

Vehicles involved

  • Car50,096 (79%)
  • Goods vehicle over 3.5 tonnes6,108 (9.6%)
  • Van or goods vehicle up to 3.5 tonnes3,747 (5.9%)
  • Motorcycle1,919 (3%)
  • Taxi or private hire car645 (1%)
  • Bus or coach435 (0.7%)
  • Other659 (1%)
  • Not recorded49 (0.1%)

Casualties by age

  • 0 to 5891 (1.9%)
  • 6 to 10980 (2.1%)
  • 11 to 151,084 (2.3%)
  • 16 to 204,311 (9.3%)
  • 21 to 257,194 (16%)
  • 26 to 3511,711 (25%)
  • 36 to 457,881 (17%)
  • 46 to 555,802 (13%)
  • 56 to 653,443 (7.4%)
  • 66 to 751,546 (3.3%)
  • Over 75726 (1.6%)
  • Not recorded769 (1.7%)

Drivers, passengers and pedestrians

  • Driver or rider28,913 (62%)
  • Passenger17,042 (37%)
  • Pedestrian383 (0.8%)

Source: Department for Transport, STATS19 road safety data

Map of recent crashes on the M4

Map of the 25 most recent crashes on the M4

Use the arrow keys to move the map and the plus and minus keys to zoom.

  • 25 crashes
  • Fatal
  • Serious
  • Slight

M4 crashes by council area

Collisions on the M4 were recorded in 22 council areas. West Berkshire has the most, with 3,187, followed by Hounslow (2,930) and Hillingdon (2,870).

Collisions on the M4 in each area, 1979 to 2025
RankAreaCollisionsCasualtiesFatalSerious
1stWest Berkshire3,1875,218118605
2ndHounslow2,9304,36239371
3rdHillingdon2,8704,27719318
4thWiltshire2,7824,65295459
5thSouth Gloucestershire2,2413,66973320
6thSlough2,1403,43339212
7thNewport2,1033,29247259
8thWindsor and Maidenhead2,0363,10864270
9thSwindon1,2402,10639231
10thCardiff1,2091,91826130
11thWokingham1,1881,87229177
12thNeath Port Talbot1,1431,87020100
13thSwansea9811,56930111
14thBridgend8641,39226124
15thBuckinghamshire5698871685
16thRhondda Cynon Taf5088321572
17thMonmouthshire4617411498
18thReading209308336
19thVale of Glamorgan184314215
20thCarmarthenshire155224624
21stBracknell Forest116175124
22ndForest of Dean5279215

M4 crashes by town

Collisions on the M4 were recorded in 23 towns and built-up areas, led by Hounslow (1,004) and Newport, Newport (549).

Recent crashes on the M4

These are the 25 most recent collisions on the M4, from 20 November to 29 December 2025.

Severity