Live M4 Traffic Cameras — London to South Wales, Updated in Real Time

Check live M4 traffic cameras before you travel between London and South Wales. We currently stream 174 camera feeds along the route, including directional coverage northbound, southbound, and at key junctions, refreshed roughly every minute. Below you'll find live route weather, any approved hazard reports, and the full camera grid by junction.

About the M4 Motorway

The M4 runs roughly 190 miles from west London to Pont Abraham near Swansea, making it the main road link between London, Reading, Bristol, and South Wales. Junction 4b connects directly to Heathrow Airport via the M4 spur, making this stretch one of the busiest airport-access corridors in the country. Further west, the motorway crosses into Wales via the Prince of Wales Bridge (formerly the Second Severn Crossing) at Junction 23, a route regularly affected by high winds due to its exposed position over the Severn Estuary.

Why Check M4 Traffic Cameras Before You Travel

Live camera access lets you:

  • Check Heathrow spur conditions — the M4/J4b link to the airport sees heavy peak and event-driven traffic
  • Monitor the Prince of Wales Bridge crossing — high winds can trigger speed restrictions or closures on this stretch
  • Spot congestion around Reading and Bristol — two of the busiest sections on the route
  • Confirm active hazards — verify reported incidents before rerouting

M4 Live Weather & Road Conditions

Our route weather snapshot is calculated from the geolocated positions of all 174 M4 cameras, giving a real average condition across the route rather than a single-point forecast.

Live route weather

M4 Weather & Driving Conditions
17°C Drizzle

Updated 22:00 UK time

Feels like 17.5°C
Rain next 3 hours 50%
Wind 2.9 mph N
Visibility 13.3 miles
Generally good conditions

No significant weather-related driving risk is indicated for this route snapshot.

23:00 Drizzle · 50% rain
16°
Route snapshot calculated from 174 geolocated cameras. Weather data by Open-Meteo

Active M4 Road Hazards

Approved driver reports for this route.

Report a Hazard
No approved active hazards are currently listed for M4.

M4 Camera Coverage by Junction

Browse M4 traffic cameras by junction below, from J1 in west London to the Welsh sections near Newport, Cardiff, and Swansea. Cameras are labelled by direction (northbound/southbound) where available.

Frequently Asked Questions

How many M4 traffic cameras are there?

There are currently 174 live camera feeds covering the M4, from west London through to South Wales.

How often do M4 camera images update?

Camera feeds refresh approximately every minute, giving a near real-time view of current traffic conditions.

Does the M4 go to Heathrow Airport?

Yes. Junction 4b connects to the M4 spur road, which leads directly to Heathrow Airport's terminals.

What is the Prince of Wales Bridge on the M4?

The Prince of Wales Bridge (formerly the Second Severn Crossing) carries the M4 across the Severn Estuary into Wales near Junction 23. It's known for being affected by high winds, which can lead to speed restrictions.

Is there a live incident or hazard report for the M4 today?

Yes — our Active M4 Road Hazards section above shows any approved driver-submitted reports in real time. If none are listed, no hazards are currently confirmed.

What are the busiest sections of the M4?

The stretch near Reading and the approach to Bristol are among the busiest, along with the Heathrow spur at Junction 4b during peak travel times.