Work on the first damaged stretch of the A6 Rothwell-Desborough bypass is complete but the road cannot re-open just yet, says Northants County Council.
The stretch over the River Ise has been shut until mid-January and was scheduled to re-open by the end of February.
But while this work is now complete, a further closure between Braybrooke Road and the B576 means the first stretch cannot re-open.
A spokesman for Northamptonshire County Council said: “We appreciate that the emergency closure to the A6, although necessary, has caused much inconvenience and we would like to thank the travelling public and local residents for their patience.
“We have looked at all possibilities in getting the A6 near Desborough re-opened as soon as possible and will continue to do so.
“Repairs have been successfully carried out on the bridge over the Ise River and now work is being done at the railway bridge on the A6 between Braybrooke Road and the B576.
“However, it is not yet possible to re-open the A6 between junction 3 of the A14 and the Braybrooke Road.
“Any diversion route we put in place must be on a like-for-like road and if we were to open this section of road, in this instance, there would not be a suitable alternative route.
“If this section of the A6 was re-opened, traffic would have to travel through the villages of Braybrooke and Little Bowden, which is not appropriate.
“Additionally we had investigated re-opening the first section of the A6 to light vehicles only, restricting HGVs.
“However, regrettably, we cannot put restrictions just to allow cars as this is off the A14 junction roundabout, which would be difficult in practical terms and could introduce safety issues on the A14 itself.”
Work on the second damaged stretch of the A6 won’t be completed until the end of April at the earliest, meaning the stretch over the River Ise won’t be open until then either.