Live incidentCarriageway closureNational Highways
M4 westbound carriageway closure between J20 and J21, live incident, started Sun 27 Sep, 21:03
- Road
- M4
- Direction
- Westbound
- Junctions
- J20 to J21
- Started
- Sun 27 Sep, 21:03
- Category
- Incident
M4 westbound lane closure between J20 and J21, 28 Sep 2026
Live incident
This incident on the M4 is in force now. It started at 03:23 on Mon 28 Sep.
Last updated by National Highways at 03:46 on Monday 28 September 2026.
Closure details and map
- Status
- Live incident
- Closure type
- Lane closure
- Category
- Incident
- Road
- M4
- Direction
- Westbound
- Junctions
- J20 to J21
- Location
- M4 westbound between J20 and J21
- Started
- 03:23 on Monday 28 September 2026
- Source
- National Highways
- Last updated by the source
- 03:46 on Monday 28 September 2026
Map of the M4 westbound lane closure between J20 and J21
Use the arrow keys to move the map and the plus and minus keys to zoom.
- Live incident
Other M4 closures and crash records
6 other closures are in force on the M4 right now, and 53 more are planned in the next 7 days.
The M4 accident statistics from 1979 to 2025 record 29,200 collisions on the road, 724 of them fatal.
- Active roadworksExit slip road closureTraffic Wales
M4 westbound exit slip road closure at J24 Coldra, active roadworks, started Sun 27 Sep, 20:00
- Road
- M4
- Direction
- Westbound
- Junctions
- J24
- Area
- J24 Coldra
- Started
- Sun 27 Sep, 20:00
- Expected to clear
- Thu 1 Oct, 06:00
- Category
- Clearance Work
- Active roadworksRoad closureTraffic Wales
M4 westbound road closure between J22 and J23, active roadworks, started Sat 26 Sep, 21:00
- Road
- M4
- Direction
- Westbound
- Junctions
- J22 to J23
- Area
- J22 Pilning/Prince of Wales Bridge to J23 Rogiet
- Started
- Sat 26 Sep, 21:00
- Expected to clear
- Fri 2 Oct, 06:00
- Category
- Roadworks
- Active roadworksExit slip road closureTraffic Wales
M4 eastbound exit slip road closure at J32 Coryton, active roadworks, started Fri 25 Sep, 20:00
- Road
- M4
- Direction
- Eastbound
- Junctions
- J32
- Area
- J32 Coryton
- Started
- Fri 25 Sep, 20:00
- Expected to clear
- Tue 29 Sep, 06:00
- Category
- Roadworks
- Active roadworksExit slip road closureTraffic Wales
M4 eastbound exit slip road closure at J35 Pencoed, active roadworks, started Tue 15 Sep, 19:00
- Road
- M4
- Direction
- Eastbound
- Junctions
- J35
- Area
- J35 Pencoed
- Started
- Tue 15 Sep, 19:00
- Expected to clear
- Fri 9 Oct, 06:00
- Category
- Clearance Work
- Active roadworksHard shoulder closureNational Highways
M4 eastbound hard shoulder closure between J17 and J16, active roadworks, started Tue 27 Apr 2021, 23:59
- Road
- M4
- Direction
- Eastbound
- Junctions
- J17 to J16
- Started
- Tue 27 Apr 2021, 23:59
- Expected to clear
- Fri 30 Jul 2027, 18:00
- Category
- Road Maintenance