Police and the air ambulance were called to the scene on the southbound carriageway in Blunsdon shortly after 8pm. Both motorways are closed between Blunsdon and Castle Eaton and National Highways said on Twitter that the main route was unlikely to reopen until Thursday morning. The tweet read: “All emergency services including ambulance are working at the scene. “The road is closed southbound between the B4040 and B4019 and northbound between the A4311 and B4040. “Wiltshire Police have advised that the road will remain closed overnight.”
