The opening of the new Rose Valley Road Bridge has put the $329 million Princes Highway upgrade at Gerringong beyond the half-way point on the road to completion, according to Roads Minister Duncan Gay.
Mr Gay said the highway was on track to be completed mid-2015, weather permitting.
As the work takes place, the nearby Kiama Bends have been the subject of major traffic delays for southbound motorists with 10-kilometre queues during holiday periods.
Mr Gay said motorists would have to endure "just one more Christmas" before they could enjoy a new highway, but he was hopeful that Roads and Maritime Services would be able to deliver a solution to minimise the impacts next holiday season, similar to the strategies put in place at South Nowra last summer.
Kiama MP Gareth Ward said motorists would still be able to travel north and south from Rose Valley Road.
"A protected right-hand turn bay will again be installed for southbound vehicles entering Rose Valley Road from the Princes Highway to improve safety," Mr Ward said.
The new bridge over the rail line at Fern Street is on track to be completed in November. However the first cars will not use the bridge until February.
The $329 million highway upgrade will provide about 7.5 kilometres of four-lane highway between Mt Pleasant and Toolijooa with two new interchanges.