Only four of the 10 bridges the Government promised to double-lane in Northland will be worked on in the next three years - and some may never be upgraded.
The New Zealand Transport Agency (NZTA) has announced a $13.9 billion plan for spending on roads and public transport across the country over the next three years.
Transport Minister Simon Bridges promised the bridge upgrades during the Northland by-election earlier this year and said the work would be done over six years.
He said today that NZTA had ruled out double-laning three of the bridges.
Those bridges are Hallahans Bridge, Lowes Bridge, and Darby and Joan Bridge, which is between two large kauri trees and which the agency says cannot be double-laned.
Mr Bridges said he was not breaking his by-election promise.
"I don't think it is unusual, though, for the government to do projects that don't necessarily meet the transport agency's criteria... We've still got other options, like funding them from the Crown."
NZTA chief executive Geoff Dangerfield said councils in Northland only had four bridges on their priority list anyway.
"We can't put something into the national programme if it isn't in a regional programme first," he said.
"For some of those other bridges, we'll be wanting to use this period to develop corridor studies and to examine those.
"I suspect, when we see the next three-year programme, we'll see what progress we can make on those then."
The Northland by-election was won by New Zealand First leader Winston Peters.