Road
Crashes on the M4
13,792 recorded collisions since 2000.
13,792
All crashes
306
Fatal
1,419
Serious
12,067
Slight
Since 2000 the M4 has seen 13,792 collisions, 306 of them fatal and 1,419 serious. That ranks it 15th of 6,754 numbered A, B and M roads by total recorded collisions. Its fatal rate is 22.2 per 1,000 collisions, and 13% caused death or serious injury. Collisions have fallen by about 75% since 2000, from 864 to 216 in 2024. The heaviest local concentrations are in Slough, Wiltshire and West Berkshire.
Worst local authorities on the M4
Select a local authority for its full profile.
- Slough1,375 crashes · 21 fatal
- Wiltshire1,319 crashes · 43 fatal
- West Berkshire1,265 crashes · 35 fatal
- Hillingdon1,202 crashes · 9 fatal
- South Gloucestershire1,103 crashes · 31 fatal
- Newport1,025 crashes · 22 fatal
- Windsor and Maidenhead1,019 crashes · 18 fatal
- Hounslow793 crashes · 7 fatal
- Neath Port Talbot766 crashes · 13 fatal
- Cardiff717 crashes · 16 fatal
Crashes by year
2000–20241,0005000
200020052010201520202024
Figures cover collisions reported to police (STATS19) from 2000 onward. Source: DfT STATS19, Open Government Licence v3.0.