EMERGENCY services have swarmed to M4 junction 15 after a two-car collision left a woman needing to be cut free from her car.
The woman was reportedly unconscious in her silver Vauxhall Astra following the incident at 8.10am this morning on the junction 15 roundabout.
Traffic is buliding along the A419 and one lane southbound will be shut for some time, a Wiltshire Police spokesman said.
The spokesman also warned motorists against attempting to avoid congestion at junction by leaving the motorway at junction 17 via the hard shoulder. This has caused traffic delays in that area.
Fire crews have been in attendance since 8.30am attempting to free the injured woman from the car, while the driver of the black Skoda Fabia was checked over but was unharmed.
A spokesman for South West Ambulance Service said: "We were called at 8.10am to a two-vehicle road traffic collision and treated one female patient with neck injuries. The injuries are not believed to be not life-changing or life-threatening.
"The fire service were called to free her from the car and she was taken to Great Western Hospital by ambulance."
The Highways Agency have said the roundabout is now clear but one lane on the southbound A419 remains shut for the time being.