Motorists asked to avoid A34 after car transporter overturns
Published: 09:00, 19 February 2015
| Updated: 16:23, 04 March 2015
Only one lane is running on the southbound carriageway.
Police have told motorists to expect significant delays and to find alternative routes wherever possible.
The Highways Agency says the road is not expected to reopen until 1pm.
Traffic for the A34 north is advised to remain on the M4 westbound to J14, then follow the Black Diamond symbol signed diversion route, to rejoin the A34 at the A4130 (Milton Interchange).
Reports on social media suggest that the air ambulance is in attendance.
This picture was posted on Twitter by Phill Davis.
More to follow.