"We understand the frustrations of motorists who've been delayed during the construction of this upgrade, but road users will now benefit from improved journey reliability, safety and freight efficiency through Whangarei," Brett Gliddon the Transport Agency's Northland Highway Manager said.
"This upgrade will improve safety for road users and reduce traffic queuing at the intersection at peak times as well as for road users and pedestrians accessing Kensington Park."
Improvements to the SH1/Kensington Avenue intersection include a new roundabout and central median barriers on the state highway between Kensington Avenue and Manse St.
The new roundabout has a dedicated northbound lane to allow vehicles travelling north to continue without stopping. This will reduce traffic queues as well as minimising potential road noise from heavy vehicles stopping on the hill at the approach to the intersection.