All emergency services have been called to an upturned vehicle that has come to rest up an embankment near Membury services.
The driver is suspected to have had a medical episode moments before the collision and remains entrapped in the vehicle
Paramedics are carrying out cycles of CPR after the driver went into cardiac arrest. It is understood that the driver has been left with life-changing injuries.
Road users are advised to follow the hollow square diversion symbol on local road signs.
- Leave the M4 at J14, at the roundabout take the first exit and join the A338.
- At the A4 mini roundabout turn right on the A4 towards Hungerford avoiding Hungerford town centre. After a short distance to the next roundabout take the 2nd exit onto Charnham Park.
- Turn right onto the B4192 and follow for approximately 13 miles through Aldbourne to the A419 roundabout.
- Take the first exit and joint he A419, continue to rejoin the M4 at J15.