The Labour Party is promising to fund half the cost of Auckland's planned city rail link by abandoning a highway upgrade north of the city.
Leader Phil Goff said the party would halt the $1.7 billion plan to upgrade State Highway 1 between Puhoi and Wellsford.
Announcing the policy in Auckland on Sunday, Mr Goff committed Labour to providing $1.2 billion towards the rail link, representing half the cost of the project.
Auckland Council would have to find the rest of the money.
The Labour leader says the rail investment would get Auckland moving and is the next step in building a modern public transport system for the city.
"This city's population is going to near-double in the next 40 years. They're not going to be in cars on the road, they're going to be on a public transport system.
"Lets get that system in place, up and running - that's what Aucklanders want, that's what the council has voted for."
Mr Goff says people in Auckland are fed up with sitting in endless traffic jams.
The party would allocate $320 million for on safety improvements on the existing Puhoi to Welllsford road.
