Noise barriers are to be installed to protect residents living near Auckland's Southern Motorway.
The New Zealand Transport Agency (NZTA) said it planned to begin construction by the middle of this year, and the project would cost $6 million.
Residents in the southern suburb of Ellerslie have long campaigned for the barriers to be installed.
The design has not been settled yet and there would be further community consultation but there would be trees planted, NZTA said.
The agency was investigating how noise barriers could be used near other sections of urban motorways in Auckland, it said.
Noise pollution from motorways has been linked in medical studies to stress, sleep deprivation and high blood pressure.