Whangarei motorists can expect months of traffic delays due to work on State Highway 1 through the city.
Contractors were beginning work on Monday to widen Western Hills Drive between the Caltex service station and Wilson Avenue.
The work involves relocating overhead power lines and underground phone lines, widening the highway and building new footpaths.
The Transport Agency says the project will benefit Whangarei but will cause widespread disruption while work is in progress.
The agency has apologised in advance and advised people to allow more time to get their destinations until the job is finished in April 2013.