Road users are advised that one lane of the A303 westbound in Somerset between Podimore Roundabout and Cartgate Roundabout has been closed for urgent repairs.
A retaining wall next to the carriageway and the verge has become unstable and requires immediate attention to ensure lane one remains safe for road users.
Work has begun to fill the ditch next to the carriageway with 3,500 tonnes of stone and install a pipe.
We will be working around the clock to ensure the lane is opened again as quickly as possible.
Work on an approximately 200ft section of the wall and verge will continue until Friday evening (1 May).
Road users are advised to check their route before setting out and allow extra time to complete journeys.
Members of the public should contact Highways England Information Line on 0300 123 5000.
Journalists should contact the Highways England press office on 0844 693 1448 and use the menu to speak to the most appropriate press officer.