Live M4 traffic news and updates for M4 junctions, plus real time travel reports on delays, accidents, roadworks and snow
The M4 is the main road running between London and South Wales, passing via Slough, Reading, Swindon, Bristol, Newport, Cardiff and Swansea along the way. Much like the rest of the UK’s road network, the M4 has its areas most likely to cause tail backs – primarily where it joins the M25 on the west of London and also where it meets the M5 near Bristol. Naturally, accidents, roadworks and other traffic issues cause delays, so it pays to be on top of your journey before you start your engine.
There used to be a toll road charge to cross the M4 Severn bridge that joins England and Wales, but after 52 years, the charge was scrapped on December 17th 2018.
Generally the majority of the M4 tends to stay relatively clear, but the 189-mile route can see extra congestion during rush hour and summer holidays. If you’re planning to use any section of the M4 motorway, this page will be a useful aid for travel alerts, live updates and an incident map for both westbound and eastbound lanes.
Tweets
Scroll down to find live tweets on the latest traffic conditions on the M4.
A Twitter List by AutoExpress
M4 live motorway cameras
If there is traffic disruption on the M4 you can keep up to date on any delays with live traffic cameras for the eastbound and westbound M4.
M4 weather report
Details of the latest weather warnings in the M5 area from the Met Office…
• Met Office South West weather report
The history of the M4
The Ministry of Transport first proposed a new road from London to South Wales in the 1930s. Plans for the M4 as one of the first major post-war trunk roads were produced in 1956 and construction began in 1961. The Chiswick flyover, a short section of elevated dual-carriageway built to reduce the impact of traffic travelling between central London and the west, opened in 1959 and later became part of the new M4 route. The section from J18 to the west of Newport was opened in 1966, including the Severn Bridge, which is now part of the M48.
The English section of the motorway was completed in December 1971 when the 50-mile stretch between Maidenhead and Swindon was opened for public use. The Welsh section was finished in 1993, when the Briton Ferry bridge opened. The Second Severn Crossing opened in 1996, and motorways on either side of the river carried the M4 over the new crossing when construction was finally completed.
• M5 traffic: live news updates
M4 junctions
All of the M4 junctions on the southbound and northbound carriageways are detailed below…
Eastbound exits (B carriageway) | Junction | Westbound exits (A carriageway) |
Road continues as A4 to Central London | J1 | Start of motorway |
North Circular A406
South Circular A205 Chiswick A315 |
J2 | Staines, Hounslow, Brentford A4 |
Heston services | Services | Heston services |
Heathrow (Terminals 4, 5 & Cargo), Hayes, Harrow, Hounslow A312 | J3 | Heathrow (Terminals 4, 5 & Cargo), Hayes, Harrow, Hounslow A312 |
Heathrow (Terminals 1, 2 & 3) (A4)
Uxbridge A408 |
J4a | Heathrow (Terminals 1, 2 & 3) (A4)
Uxbridge A408 |
Heathrow (Terminals 4, 5 & Cargo) , Gatwick Airport , Watford (M3), (M23), (M40), (M1) M25 | J4b | Heathrow (Terminals 4, 5&Cargo), Gatwick, Watford (M3), (M23), (M40), (M1), M25 |
Colnbrook, Langley, Slough (East) A4
Eton, Datchet B470 |
J5 | Colnbrook, Langley, Slough (East) A4, Datchet B470 |
Slough (Central) A355
Windsor A322 |
J6 | Slough (Central) A355
Windsor A322 |
Slough (West) A4 | J7 | Slough (West) A4 |
High Wycombe, Henley A404(M)
Maidenhead A308(M) |
J8/9 | High Wycombe, Henley A404(M)
Maidenhead A308(M) |
Reading (East), Wokingham, Bracknell A329(M) | J10 | Reading (East), Wokingham, Bracknell A329(M) |
Basingstoke, Reading (Central & South) A33 | J11 | Basingstoke, Reading (Central & South) A33 |
Reading services | Services | Reading services |
Reading (West), Theale A4 | J12 | Reading (West), Theale A4 |
Newbury, Oxford A34
Chieveley services (Moto) |
J13
Services |
Newbury, Oxford A34
Chieveley services (Moto) |
Hungerford, Wantage A338 | J14 | Hungerford, Wantage A338 |
Membury services | Services | Membury services |
Swindon (East) A419
Marlborough A346 Oxford (A420) |
J15 | Swindon A419, Marlborough A346 |
Swindon (West), Royal Wootton Bassett, Wroughton, RAF Lyneham, Calne A3102 | J16 | Swindon (West), Royal Wootton Bassett, Wroughton, RAF Lyneham, Calne A3102 |
Chippenham A350
Cirencester A429 |
J17 | Chippenham A350
Cirencester A429 |
Leigh Delamere services | Services | Leigh Delamere services |
Bath, Stroud A46 | J18 | Bath, Stroud A46 |
Bristol M32 | J19 | Bristol M32 |
The SOUTH WEST, Bristol (West), The MIDLANDS, Gloucester M5 | J20
Almondsbury Interchange |
The SOUTH WEST, Bristol (West) M5(S)
The MIDLANDS, Gloucester M5(N) |
No access | J21 | Chepstow M48 |
Avonmouth M49 | J22 | Avonmouth M49 |
Entry into England | Second Severn Crossing | Entry into Wales |
No toll plaza | Bridge Toll | Toll plaza |
Chepstow M48 | J23 | No access |
Magor, Caldicot A4810
Magor services |
J23A
Services |
Magor, Caldicot A4810
Magor services |
City centre A48
Newport (East) B4237 Monmouth A449 The MIDLANDS (M50) |
J24 | City centre A48
Newport (East) B4237 Monmouth A449 |
No access | J25 | Caerleon B4596 |
No access | J25A | Newport, Cwmbran A4042 |
Brynglas Tunnels | Tunnel | Brynglas Tunnels |
Newport, Cwmbran, Caerleon A4051 | J26 | Newport A4051 |
High Cross B4591 | J27 | High Cross B4591 |
Newport A48
Risca, Brynmawr A467 |
J28 | Newport A48
Risca, Brynmawr A467 |
No access | J29 | Cardiff (East and South) A48(M) |
Cardiff (East) A4232
Cardiff Gate services |
J30
Services |
Cardiff (East) A4232
Cardiff Gate services |
Merthyr Tydfil, Cardiff A470 | J32 | Cardiff (North), Merthyr Tydfil A470 |
Cardiff (West), Barry, Penarth A4232
Cardiff Airport Cardiff West services |
J33
Services |
Cardiff (West), Barry, Penarth A4232
Cardiff Airport Cardiff West services |
Llantrisant, Rhondda A4119
Royal Glamorgan Hospital |
J34 | Llantrisant, Rhondda A4119
Royal Glamorgan Hospital |
Pen-coed A473 | J35 | Bridgend, Pen-coed A473 |
Bridgend A4061
Maesteg A4063 Princess of Wales Hospital Sarn Park services |
J36
Services |
Bridgend A4061
Maesteg A4063 Princess of Wales Hospital Sarn Park services |
Pyle, Porthcawl A4229 | J37 | Porthcawl, Pyle A4229 |
Port Talbot A48 | J38 | Port Talbot A48 |
No access (on-ramp only) | J39 | No access |
Port Talbot A4107 | J40 | Port Talbot A4107 |
Port Talbot A48 | J41 | Briton Ferry A48 |
Briton Ferry A48
Swansea (South) A483 |
J42 | Swansea (South) A483 |
Neath, Merthyr Tydfil A465 | J43 | Neath, Merthyr Tydfil A465 |
Swansea (East) A48 | J44 | Swansea (East) A48 |
Pontardawe, Swansea (North) A4067 | J45 | Pontardawe, Swansea (North) A4067 |
Llangyfelach B4489
Felindre Morriston Hospital |
J46 | Llangyfelach B4489
Felindre Morriston Hospital |
Swansea (West) A483
Gorseinon A48 Swansea services |
J47
Services |
Swansea (West) A483
Gorseinon A48 Swansea services |
Pontarddulais, Llanelli A4138 | J48 | Pontarddulais, Llanelli A4138 |
Start of motorway | J49
Terminus Services |
Motorway terminates at a roundabout:
Carmarthen A48 Ammanford, Llandeilo A483 Pontarddulais A48 Pont Abraham services |
Keyword: Latest live M4 traffic news