The new stage of the work will also cause changes that mean access from Mornington Rd to Riselaw Rd and South Rd, via the highway, will no longer be available until the bridge is completed.
And project managers have called for increased attention by motorists to changing conditions as the work progresses, to keep workers safe.
The work is part of stage two of the improvement project.
In stage one, the highway between Andersons Bay Rd and Barnes Dr was widened to a consistent four lanes.
The second stage is widening and realigning the highway from Barnes Dr to Lookout Point, and includes the new bridge connecting Mornington Rd and Riselaw Rd.
The project hit substantial below-ground problems that pushed completion back to late May next year, and its budget upwards of $23 million.
New Zealand Transport Agency project manager Simon Underwood said the northern embankment of the bridge would begin to take shape soon on the Mornington side, as foundation work was complete.
On the other side of the road, pre-excavation and piling work would begin.
The bridge would be 6.5m above the highway, allowing trucks with large loads, such as houses or heavy machinery, to pass underneath.
The need for more space for contractors to work meant there would be restrictions on turning.
Those included an end to the right hand turn to Riselaw Rd and South Rd from vehicles on the highway heading to the city.
The agency said about 500 vehicles a day made the right-hand turn to Riselaw Rd.
About half had come from Mornington Rd and the rest was highway traffic headed towards the city.
The aim was for the change to be put in place next Monday week.
As well, the Concord off-ramp will be closed for Dunedin City Council road work from September 29 to October 12, meaning that option for accessing Corstorphine was also temporarily blocked.
Mr Underwood also said motorists needed to keep to speed limits as they drove through what was a work site.
''Speed through the site has at times been an issue,'' he said.
The issue was particularly important for those coming up the highway from Green Island, as it was not possible tell what would be happening over the rise.
Drivers needed to keep a close eye on signs through the stretch of road as the work took place.
