The final layer of surfacing will be completed in November.
Waka Kotahi NZTA asked road users to keep to the speed limits and watch out for crews on the roadside.
Signs are in place to advise road users of the upcoming road layout changes.
While the new roundabout will be open, the community is being advised to expect delays as people get used to the new road layout and while the roundabout continues to be an active worksite for the next few weeks as final works are completed.
Waka Kotahi acknowledged the upgrade was a disruptive piece of work and thanked the local community and road users, especially those who commute through the work site daily, for their patience during recent months.