A “multiple vehicle collision” has blocked a section of the M4 eastbound, with emergency services on the scene.
The crash happened at J20, and traffic officers have closed the road while emergency services work on the carriageways.
Avon Fire and Rescue has been contacted for further information.
National Highways said on Twitter that there is congestion of over two miles, and they advise motorists to allow extra time for journeys.
Traffic monitoring service Inrix says: “M4 Eastbound blocked, stationary traffic due to accident at J20 M5 J15 (Almondsbury Interchange). Congestion to M48 J21 (M48 Interchange). In the roadworks area.
“Camera confirms Traffic has been held, delays not helped by ongoing roadworks, affecting traffic approaching Bristol from Wales.”
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