The four lane roadworks are not expected to be fully complete until the end of quarter one 2023.
Donegal County Council says the major road works on the main road into Letterkenny has been severely affected by global supply and inflation issues arising out of international events.
The Four Lane works between Dry Arch and Polestar Roundabouts have been significantly progressed, according to officials, with works on the road and footway elements up to 80% complete.
However, associated elements are not expected to be complete until the end of March next year.
The council also confirmed the works will be shut down from the period of December 16th to the first week in January to allow free movement of Christmas traffic.
