Devon County Council is closing the A386 at Weare Giffard for 10 weeks to carry out structural repairs.
The A386 between Bideford and Torrington is being closed for 10 weeks to carry out structural repairs.
Devon County Council has closed the road today (Thursday) to carry out repairs, with a diversion in place.
A DCC spokesman said: “We have been monitoring a section of old highway retaining wall on the A386 at Landcross over the past year as it has been showing signs of structural distress and has resulted in major depressions and cracking in the road.
“Because the road is continuing to deteriorate we have closed the road from today (Thursday) in order to carry out full structural repairs, including building a new retaining wall.
“For the safety of the workforce and the public, the road will be closed for 10 weeks.
“The diversion route for HGV vehicles will be via A386 north towards Bideford, A39 to Roundswell, B3232, Great Torrington onto A386 and vice versa.
“The diversion route for small vehicles during this time will be via A388, Frithelstock onto A386 and vice versa.
“After the more complex construction work has been completed during the 10 weeks, temporary traffic lights will be installed for the completion of the remainder of the work.”
The road was also closed on November 12 after the landslip at Weare Giffard brought down five trees.
It is understood the council will use this road closure to try to address the landslide, but further closures may be needed.