Devon County Council is unable to say how long the work will take, although a geotechnical report has now been completed and design work is nearly finished.
The report blames the problems on subsidence, which has caused the road surface to crack. Traffic lights were first installed in March this year, when the subsidence problem was first noticed.
A council spokesman said: ‘Cracking and subsidence was discovered on this stretch of the A379 at the end of March, when planned fencing work was due to take place.
‘Site investigations were delayed while a gas main was located and necessary risk assessments were approved by Wales and West Utilities.
‘Soil samples have been analysed as part of the geotechnical report and work on the scheme design is nearing completion.
‘Until this is complete it isn’t possible to give an accurate duration of the scheme, but it is hoped that work will get under way at the start of the new year.’