Research is under way for a second bridge across the Manukau Harbour.
The options being studied range from a new bridge, alongside the present one, to a cheaper plan of adding lanes to the existing structure.
Transit New Zealand's regional transportation engineer, John Hughes, says the existing bridge, connecting Mangere and Onehunga,
is operating at capacity.
The four-lane bridge carries 80,000 vehicles a day and traffic flows are often brought to a standstill at peak times or after accidents.
Mr Hughes says a final plan must allow for the future construction of a rapid transit link between the inner city and the airport.
Manukau City councillor John Kerr says residents want the project fast-tracked. "We've been saying for a long time that the traffic on the bridge is a continual problem."
The project is one of seven studies aimed at developing an alternative route to the Southern Motorway.
Opus International Consultants is doing preliminary research and has held meetings in Onehunga and Mangere.
