The work is expected to take 10 weeks and be completed in early December.
The new layout will improve safety for motorists, cyclists and pedestrians. The current roundabout has no protected centre islands for pedestrians attempting to navigate its wide crossings.
The rebuild includes removing left turn slip lanes to improve safety, improving merging facilities for cyclists, and creating safe crossing points for pedestrians. It will operate similarly to the Albert/Ferguson Street roundabout.
NZTA is meeting half the cost of the upgrade.
Higgins Contractors are carrying out the work, with the expected hours to be between Mondays and Fridays from 6.30am to 6.30pm. There may be some weekend work depending on weather. Property owners in the vicinity of the construction site have been informed of the work.
The roundabout will continue to operate during most of the construction period, however Council advises people to travel with caution or avoid the intersection if possible.