Council spokesman Jack Barlow said a lot of the work has been completed, but from the end of this month contractors would be off site for the winter "no sealing" period and would not return until September.
He said work on the project began in December.
The council had worked closely with other agencies such as Aurora to replace more than 50 power poles along the road and telco providers to relocate current underground telco services and facilitate future upgrades to future-proof the network.
Contractors have completed sealing, widening and upgrades to drainage, as well as relocating fences along the western end of the road.
"Due to the extra scope of work [specifically the telco upgrades] it has taken a little longer to complete the work than expected.
"Unfortunately we are not able to complete the sealing of the eastern end of the road over the colder winter months," Mr Barlow said.
Jackson Aitchison (17) was killed when the car he was driving left the road and crashed head-on into a tree on Ballantyne Rd in October 2016.
Recent coronial findings found the gravel road might have contributed to the crash.
Coroner Brigitte Windley said there was a history of crashes in Ballantyne Rd, and the Queenstown Lakes District council was aware of her concerns.
"I do however, strongly encourage the prioritisation of these works, to the extent there is scope for that, and request that the Office of the Chief Coroner be notified once these works have been completed," Ms Windley said.
Mr Barlow said Wanaka residents could expect the current Ballantyne Rd closure to remain in place from Monday to Saturday, 6am to 9pm, until the end of June.
A temporary speed limit of 50kmh would be in place over this time.
"The road will also be regularly graded to keep the unsealed section tidy and safe," he said.
The contractors would return to the site in mid-September. The goal was for the remaining 2.4km of road sealed and the overall project to be completed by the end of October, Mr Barlow said.
