A30 between Yeovil and Crewkerne to face disruption for 13 weeks
A key A-road in Somerset will be closed or partially closed for 13 weeks while essential repairs take place.
The A30 will initially shut between Yeovil and Crewkerne, near to near the village of Haselbury Plucknett, for three weeks from 7 February, causing diversions of up to 18 miles (29km).
There will then be a single-lane closure and temporary traffic lights for 10 weeks.
Somerset County Council said a "deteriorating" wall must be replaced.
It said the wall was at risk of becoming "a serious road hazard".
The road will initially be fully closed immediately north of the junction with the A3066, which heads through Haselbury Plucknett to Bridport.
Motorists heading to Yeovil from Crewkerne will face a long diversion along the A356 and A303 and A3088, according to the Local Democracy Reporting Service.
But during this first phase, traffic heading to and from Haselbury Plucknett will still be able to head west on the A30 towards Crewkerne and Chard.
Some access maintained
From 28 February, a single lane of the A30 will reopen, with three-way traffic lights in operation.
The project is expected to be completed by 20 May.
County councillor John Woodman, cabinet member for highways and transport, said it was "critical" the wall was fixed now so that the Yeovil Road remained safe for the travelling public.
"Unfortunately, this means that the road needs to be closed while work is carried out, but the team has tried to keep this to the minimum amount of time possible and to plan it, so it doesn't affect the holiday season," he added.
Access to households and businesses in the area will be maintained throughout the roadworks on the A30, with pedestrian access also remaining in place.